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1
+ from sympy.core import Add, Mul, Pow, S
2
+ from sympy.core.basic import Basic
3
+ from sympy.core.expr import Expr
4
+ from sympy.core.numbers import _sympifyit, oo, zoo
5
+ from sympy.core.relational import is_le, is_lt, is_ge, is_gt
6
+ from sympy.core.sympify import _sympify
7
+ from sympy.functions.elementary.miscellaneous import Min, Max
8
+ from sympy.logic.boolalg import And
9
+ from sympy.multipledispatch import dispatch
10
+ from sympy.series.order import Order
11
+ from sympy.sets.sets import FiniteSet
12
+
13
+
14
+ class AccumulationBounds(Expr):
15
+ r"""An accumulation bounds.
16
+
17
+ # Note AccumulationBounds has an alias: AccumBounds
18
+
19
+ AccumulationBounds represent an interval `[a, b]`, which is always closed
20
+ at the ends. Here `a` and `b` can be any value from extended real numbers.
21
+
22
+ The intended meaning of AccummulationBounds is to give an approximate
23
+ location of the accumulation points of a real function at a limit point.
24
+
25
+ Let `a` and `b` be reals such that `a \le b`.
26
+
27
+ `\left\langle a, b\right\rangle = \{x \in \mathbb{R} \mid a \le x \le b\}`
28
+
29
+ `\left\langle -\infty, b\right\rangle = \{x \in \mathbb{R} \mid x \le b\} \cup \{-\infty, \infty\}`
30
+
31
+ `\left\langle a, \infty \right\rangle = \{x \in \mathbb{R} \mid a \le x\} \cup \{-\infty, \infty\}`
32
+
33
+ `\left\langle -\infty, \infty \right\rangle = \mathbb{R} \cup \{-\infty, \infty\}`
34
+
35
+ ``oo`` and ``-oo`` are added to the second and third definition respectively,
36
+ since if either ``-oo`` or ``oo`` is an argument, then the other one should
37
+ be included (though not as an end point). This is forced, since we have,
38
+ for example, ``1/AccumBounds(0, 1) = AccumBounds(1, oo)``, and the limit at
39
+ `0` is not one-sided. As `x` tends to `0-`, then `1/x \rightarrow -\infty`, so `-\infty`
40
+ should be interpreted as belonging to ``AccumBounds(1, oo)`` though it need
41
+ not appear explicitly.
42
+
43
+ In many cases it suffices to know that the limit set is bounded.
44
+ However, in some other cases more exact information could be useful.
45
+ For example, all accumulation values of `\cos(x) + 1` are non-negative.
46
+ (``AccumBounds(-1, 1) + 1 = AccumBounds(0, 2)``)
47
+
48
+ A AccumulationBounds object is defined to be real AccumulationBounds,
49
+ if its end points are finite reals.
50
+
51
+ Let `X`, `Y` be real AccumulationBounds, then their sum, difference,
52
+ product are defined to be the following sets:
53
+
54
+ `X + Y = \{ x+y \mid x \in X \cap y \in Y\}`
55
+
56
+ `X - Y = \{ x-y \mid x \in X \cap y \in Y\}`
57
+
58
+ `X \times Y = \{ x \times y \mid x \in X \cap y \in Y\}`
59
+
60
+ When an AccumBounds is raised to a negative power, if 0 is contained
61
+ between the bounds then an infinite range is returned, otherwise if an
62
+ endpoint is 0 then a semi-infinite range with consistent sign will be returned.
63
+
64
+ AccumBounds in expressions behave a lot like Intervals but the
65
+ semantics are not necessarily the same. Division (or exponentiation
66
+ to a negative integer power) could be handled with *intervals* by
67
+ returning a union of the results obtained after splitting the
68
+ bounds between negatives and positives, but that is not done with
69
+ AccumBounds. In addition, bounds are assumed to be independent of
70
+ each other; if the same bound is used in more than one place in an
71
+ expression, the result may not be the supremum or infimum of the
72
+ expression (see below). Finally, when a boundary is ``1``,
73
+ exponentiation to the power of ``oo`` yields ``oo``, neither
74
+ ``1`` nor ``nan``.
75
+
76
+ Examples
77
+ ========
78
+
79
+ >>> from sympy import AccumBounds, sin, exp, log, pi, E, S, oo
80
+ >>> from sympy.abc import x
81
+
82
+ >>> AccumBounds(0, 1) + AccumBounds(1, 2)
83
+ AccumBounds(1, 3)
84
+
85
+ >>> AccumBounds(0, 1) - AccumBounds(0, 2)
86
+ AccumBounds(-2, 1)
87
+
88
+ >>> AccumBounds(-2, 3)*AccumBounds(-1, 1)
89
+ AccumBounds(-3, 3)
90
+
91
+ >>> AccumBounds(1, 2)*AccumBounds(3, 5)
92
+ AccumBounds(3, 10)
93
+
94
+ The exponentiation of AccumulationBounds is defined
95
+ as follows:
96
+
97
+ If 0 does not belong to `X` or `n > 0` then
98
+
99
+ `X^n = \{ x^n \mid x \in X\}`
100
+
101
+ >>> AccumBounds(1, 4)**(S(1)/2)
102
+ AccumBounds(1, 2)
103
+
104
+ otherwise, an infinite or semi-infinite result is obtained:
105
+
106
+ >>> 1/AccumBounds(-1, 1)
107
+ AccumBounds(-oo, oo)
108
+ >>> 1/AccumBounds(0, 2)
109
+ AccumBounds(1/2, oo)
110
+ >>> 1/AccumBounds(-oo, 0)
111
+ AccumBounds(-oo, 0)
112
+
113
+ A boundary of 1 will always generate all nonnegatives:
114
+
115
+ >>> AccumBounds(1, 2)**oo
116
+ AccumBounds(0, oo)
117
+ >>> AccumBounds(0, 1)**oo
118
+ AccumBounds(0, oo)
119
+
120
+ If the exponent is itself an AccumulationBounds or is not an
121
+ integer then unevaluated results will be returned unless the base
122
+ values are positive:
123
+
124
+ >>> AccumBounds(2, 3)**AccumBounds(-1, 2)
125
+ AccumBounds(1/3, 9)
126
+ >>> AccumBounds(-2, 3)**AccumBounds(-1, 2)
127
+ AccumBounds(-2, 3)**AccumBounds(-1, 2)
128
+
129
+ >>> AccumBounds(-2, -1)**(S(1)/2)
130
+ sqrt(AccumBounds(-2, -1))
131
+
132
+ Note: `\left\langle a, b\right\rangle^2` is not same as `\left\langle a, b\right\rangle \times \left\langle a, b\right\rangle`
133
+
134
+ >>> AccumBounds(-1, 1)**2
135
+ AccumBounds(0, 1)
136
+
137
+ >>> AccumBounds(1, 3) < 4
138
+ True
139
+
140
+ >>> AccumBounds(1, 3) < -1
141
+ False
142
+
143
+ Some elementary functions can also take AccumulationBounds as input.
144
+ A function `f` evaluated for some real AccumulationBounds `\left\langle a, b \right\rangle`
145
+ is defined as `f(\left\langle a, b\right\rangle) = \{ f(x) \mid a \le x \le b \}`
146
+
147
+ >>> sin(AccumBounds(pi/6, pi/3))
148
+ AccumBounds(1/2, sqrt(3)/2)
149
+
150
+ >>> exp(AccumBounds(0, 1))
151
+ AccumBounds(1, E)
152
+
153
+ >>> log(AccumBounds(1, E))
154
+ AccumBounds(0, 1)
155
+
156
+ Some symbol in an expression can be substituted for a AccumulationBounds
157
+ object. But it does not necessarily evaluate the AccumulationBounds for
158
+ that expression.
159
+
160
+ The same expression can be evaluated to different values depending upon
161
+ the form it is used for substitution since each instance of an
162
+ AccumulationBounds is considered independent. For example:
163
+
164
+ >>> (x**2 + 2*x + 1).subs(x, AccumBounds(-1, 1))
165
+ AccumBounds(-1, 4)
166
+
167
+ >>> ((x + 1)**2).subs(x, AccumBounds(-1, 1))
168
+ AccumBounds(0, 4)
169
+
170
+ References
171
+ ==========
172
+
173
+ .. [1] https://en.wikipedia.org/wiki/Interval_arithmetic
174
+
175
+ .. [2] https://fab.cba.mit.edu/classes/S62.12/docs/Hickey_interval.pdf
176
+
177
+ Notes
178
+ =====
179
+
180
+ Do not use ``AccumulationBounds`` for floating point interval arithmetic
181
+ calculations, use ``mpmath.iv`` instead.
182
+ """
183
+
184
+ is_extended_real = True
185
+ is_number = False
186
+
187
+ def __new__(cls, min, max):
188
+
189
+ min = _sympify(min)
190
+ max = _sympify(max)
191
+
192
+ # Only allow real intervals (use symbols with 'is_extended_real=True').
193
+ if not min.is_extended_real or not max.is_extended_real:
194
+ raise ValueError("Only real AccumulationBounds are supported")
195
+
196
+ if max == min:
197
+ return max
198
+
199
+ # Make sure that the created AccumBounds object will be valid.
200
+ if max.is_number and min.is_number:
201
+ bad = max.is_comparable and min.is_comparable and max < min
202
+ else:
203
+ bad = (max - min).is_extended_negative
204
+ if bad:
205
+ raise ValueError(
206
+ "Lower limit should be smaller than upper limit")
207
+
208
+ return Basic.__new__(cls, min, max)
209
+
210
+ # setting the operation priority
211
+ _op_priority = 11.0
212
+
213
+ def _eval_is_real(self):
214
+ if self.min.is_real and self.max.is_real:
215
+ return True
216
+
217
+ @property
218
+ def min(self):
219
+ """
220
+ Returns the minimum possible value attained by AccumulationBounds
221
+ object.
222
+
223
+ Examples
224
+ ========
225
+
226
+ >>> from sympy import AccumBounds
227
+ >>> AccumBounds(1, 3).min
228
+ 1
229
+
230
+ """
231
+ return self.args[0]
232
+
233
+ @property
234
+ def max(self):
235
+ """
236
+ Returns the maximum possible value attained by AccumulationBounds
237
+ object.
238
+
239
+ Examples
240
+ ========
241
+
242
+ >>> from sympy import AccumBounds
243
+ >>> AccumBounds(1, 3).max
244
+ 3
245
+
246
+ """
247
+ return self.args[1]
248
+
249
+ @property
250
+ def delta(self):
251
+ """
252
+ Returns the difference of maximum possible value attained by
253
+ AccumulationBounds object and minimum possible value attained
254
+ by AccumulationBounds object.
255
+
256
+ Examples
257
+ ========
258
+
259
+ >>> from sympy import AccumBounds
260
+ >>> AccumBounds(1, 3).delta
261
+ 2
262
+
263
+ """
264
+ return self.max - self.min
265
+
266
+ @property
267
+ def mid(self):
268
+ """
269
+ Returns the mean of maximum possible value attained by
270
+ AccumulationBounds object and minimum possible value
271
+ attained by AccumulationBounds object.
272
+
273
+ Examples
274
+ ========
275
+
276
+ >>> from sympy import AccumBounds
277
+ >>> AccumBounds(1, 3).mid
278
+ 2
279
+
280
+ """
281
+ return (self.min + self.max) / 2
282
+
283
+ @_sympifyit('other', NotImplemented)
284
+ def _eval_power(self, other):
285
+ return self.__pow__(other)
286
+
287
+ @_sympifyit('other', NotImplemented)
288
+ def __add__(self, other):
289
+ if isinstance(other, Expr):
290
+ if isinstance(other, AccumBounds):
291
+ return AccumBounds(
292
+ Add(self.min, other.min),
293
+ Add(self.max, other.max))
294
+ if other is S.Infinity and self.min is S.NegativeInfinity or \
295
+ other is S.NegativeInfinity and self.max is S.Infinity:
296
+ return AccumBounds(-oo, oo)
297
+ elif other.is_extended_real:
298
+ if self.min is S.NegativeInfinity and self.max is S.Infinity:
299
+ return AccumBounds(-oo, oo)
300
+ elif self.min is S.NegativeInfinity:
301
+ return AccumBounds(-oo, self.max + other)
302
+ elif self.max is S.Infinity:
303
+ return AccumBounds(self.min + other, oo)
304
+ else:
305
+ return AccumBounds(Add(self.min, other), Add(self.max, other))
306
+ return Add(self, other, evaluate=False)
307
+ return NotImplemented
308
+
309
+ __radd__ = __add__
310
+
311
+ def __neg__(self):
312
+ return AccumBounds(-self.max, -self.min)
313
+
314
+ @_sympifyit('other', NotImplemented)
315
+ def __sub__(self, other):
316
+ if isinstance(other, Expr):
317
+ if isinstance(other, AccumBounds):
318
+ return AccumBounds(
319
+ Add(self.min, -other.max),
320
+ Add(self.max, -other.min))
321
+ if other is S.NegativeInfinity and self.min is S.NegativeInfinity or \
322
+ other is S.Infinity and self.max is S.Infinity:
323
+ return AccumBounds(-oo, oo)
324
+ elif other.is_extended_real:
325
+ if self.min is S.NegativeInfinity and self.max is S.Infinity:
326
+ return AccumBounds(-oo, oo)
327
+ elif self.min is S.NegativeInfinity:
328
+ return AccumBounds(-oo, self.max - other)
329
+ elif self.max is S.Infinity:
330
+ return AccumBounds(self.min - other, oo)
331
+ else:
332
+ return AccumBounds(
333
+ Add(self.min, -other),
334
+ Add(self.max, -other))
335
+ return Add(self, -other, evaluate=False)
336
+ return NotImplemented
337
+
338
+ @_sympifyit('other', NotImplemented)
339
+ def __rsub__(self, other):
340
+ return self.__neg__() + other
341
+
342
+ @_sympifyit('other', NotImplemented)
343
+ def __mul__(self, other):
344
+ if self.args == (-oo, oo):
345
+ return self
346
+ if isinstance(other, Expr):
347
+ if isinstance(other, AccumBounds):
348
+ if other.args == (-oo, oo):
349
+ return other
350
+ v = set()
351
+ for a in self.args:
352
+ vi = other*a
353
+ v.update(vi.args or (vi,))
354
+ return AccumBounds(Min(*v), Max(*v))
355
+ if other is S.Infinity:
356
+ if self.min.is_zero:
357
+ return AccumBounds(0, oo)
358
+ if self.max.is_zero:
359
+ return AccumBounds(-oo, 0)
360
+ if other is S.NegativeInfinity:
361
+ if self.min.is_zero:
362
+ return AccumBounds(-oo, 0)
363
+ if self.max.is_zero:
364
+ return AccumBounds(0, oo)
365
+ if other.is_extended_real:
366
+ if other.is_zero:
367
+ if self.max is S.Infinity:
368
+ return AccumBounds(0, oo)
369
+ if self.min is S.NegativeInfinity:
370
+ return AccumBounds(-oo, 0)
371
+ return S.Zero
372
+ if other.is_extended_positive:
373
+ return AccumBounds(
374
+ Mul(self.min, other),
375
+ Mul(self.max, other))
376
+ elif other.is_extended_negative:
377
+ return AccumBounds(
378
+ Mul(self.max, other),
379
+ Mul(self.min, other))
380
+ if isinstance(other, Order):
381
+ return other
382
+ return Mul(self, other, evaluate=False)
383
+ return NotImplemented
384
+
385
+ __rmul__ = __mul__
386
+
387
+ @_sympifyit('other', NotImplemented)
388
+ def __truediv__(self, other):
389
+ if isinstance(other, Expr):
390
+ if isinstance(other, AccumBounds):
391
+ if other.min.is_positive or other.max.is_negative:
392
+ return self * AccumBounds(1/other.max, 1/other.min)
393
+
394
+ if (self.min.is_extended_nonpositive and self.max.is_extended_nonnegative and
395
+ other.min.is_extended_nonpositive and other.max.is_extended_nonnegative):
396
+ if self.min.is_zero and other.min.is_zero:
397
+ return AccumBounds(0, oo)
398
+ if self.max.is_zero and other.min.is_zero:
399
+ return AccumBounds(-oo, 0)
400
+ return AccumBounds(-oo, oo)
401
+
402
+ if self.max.is_extended_negative:
403
+ if other.min.is_extended_negative:
404
+ if other.max.is_zero:
405
+ return AccumBounds(self.max / other.min, oo)
406
+ if other.max.is_extended_positive:
407
+ # if we were dealing with intervals we would return
408
+ # Union(Interval(-oo, self.max/other.max),
409
+ # Interval(self.max/other.min, oo))
410
+ return AccumBounds(-oo, oo)
411
+
412
+ if other.min.is_zero and other.max.is_extended_positive:
413
+ return AccumBounds(-oo, self.max / other.max)
414
+
415
+ if self.min.is_extended_positive:
416
+ if other.min.is_extended_negative:
417
+ if other.max.is_zero:
418
+ return AccumBounds(-oo, self.min / other.min)
419
+ if other.max.is_extended_positive:
420
+ # if we were dealing with intervals we would return
421
+ # Union(Interval(-oo, self.min/other.min),
422
+ # Interval(self.min/other.max, oo))
423
+ return AccumBounds(-oo, oo)
424
+
425
+ if other.min.is_zero and other.max.is_extended_positive:
426
+ return AccumBounds(self.min / other.max, oo)
427
+
428
+ elif other.is_extended_real:
429
+ if other in (S.Infinity, S.NegativeInfinity):
430
+ if self == AccumBounds(-oo, oo):
431
+ return AccumBounds(-oo, oo)
432
+ if self.max is S.Infinity:
433
+ return AccumBounds(Min(0, other), Max(0, other))
434
+ if self.min is S.NegativeInfinity:
435
+ return AccumBounds(Min(0, -other), Max(0, -other))
436
+ if other.is_extended_positive:
437
+ return AccumBounds(self.min / other, self.max / other)
438
+ elif other.is_extended_negative:
439
+ return AccumBounds(self.max / other, self.min / other)
440
+ if (1 / other) is S.ComplexInfinity:
441
+ return Mul(self, 1 / other, evaluate=False)
442
+ else:
443
+ return Mul(self, 1 / other)
444
+
445
+ return NotImplemented
446
+
447
+ @_sympifyit('other', NotImplemented)
448
+ def __rtruediv__(self, other):
449
+ if isinstance(other, Expr):
450
+ if other.is_extended_real:
451
+ if other.is_zero:
452
+ return S.Zero
453
+ if (self.min.is_extended_nonpositive and self.max.is_extended_nonnegative):
454
+ if self.min.is_zero:
455
+ if other.is_extended_positive:
456
+ return AccumBounds(Mul(other, 1 / self.max), oo)
457
+ if other.is_extended_negative:
458
+ return AccumBounds(-oo, Mul(other, 1 / self.max))
459
+ if self.max.is_zero:
460
+ if other.is_extended_positive:
461
+ return AccumBounds(-oo, Mul(other, 1 / self.min))
462
+ if other.is_extended_negative:
463
+ return AccumBounds(Mul(other, 1 / self.min), oo)
464
+ return AccumBounds(-oo, oo)
465
+ else:
466
+ return AccumBounds(Min(other / self.min, other / self.max),
467
+ Max(other / self.min, other / self.max))
468
+ return Mul(other, 1 / self, evaluate=False)
469
+ else:
470
+ return NotImplemented
471
+
472
+ @_sympifyit('other', NotImplemented)
473
+ def __pow__(self, other):
474
+ if isinstance(other, Expr):
475
+ if other is S.Infinity:
476
+ if self.min.is_extended_nonnegative:
477
+ if self.max < 1:
478
+ return S.Zero
479
+ if self.min > 1:
480
+ return S.Infinity
481
+ return AccumBounds(0, oo)
482
+ elif self.max.is_extended_negative:
483
+ if self.min > -1:
484
+ return S.Zero
485
+ if self.max < -1:
486
+ return zoo
487
+ return S.NaN
488
+ else:
489
+ if self.min > -1:
490
+ if self.max < 1:
491
+ return S.Zero
492
+ return AccumBounds(0, oo)
493
+ return AccumBounds(-oo, oo)
494
+
495
+ if other is S.NegativeInfinity:
496
+ return (1/self)**oo
497
+
498
+ # generically true
499
+ if (self.max - self.min).is_nonnegative:
500
+ # well defined
501
+ if self.min.is_nonnegative:
502
+ # no 0 to worry about
503
+ if other.is_nonnegative:
504
+ # no infinity to worry about
505
+ return self.func(self.min**other, self.max**other)
506
+
507
+ if other.is_zero:
508
+ return S.One # x**0 = 1
509
+
510
+ if other.is_Integer or other.is_integer:
511
+ if self.min.is_extended_positive:
512
+ return AccumBounds(
513
+ Min(self.min**other, self.max**other),
514
+ Max(self.min**other, self.max**other))
515
+ elif self.max.is_extended_negative:
516
+ return AccumBounds(
517
+ Min(self.max**other, self.min**other),
518
+ Max(self.max**other, self.min**other))
519
+
520
+ if other % 2 == 0:
521
+ if other.is_extended_negative:
522
+ if self.min.is_zero:
523
+ return AccumBounds(self.max**other, oo)
524
+ if self.max.is_zero:
525
+ return AccumBounds(self.min**other, oo)
526
+ return (1/self)**(-other)
527
+ return AccumBounds(
528
+ S.Zero, Max(self.min**other, self.max**other))
529
+ elif other % 2 == 1:
530
+ if other.is_extended_negative:
531
+ if self.min.is_zero:
532
+ return AccumBounds(self.max**other, oo)
533
+ if self.max.is_zero:
534
+ return AccumBounds(-oo, self.min**other)
535
+ return (1/self)**(-other)
536
+ return AccumBounds(self.min**other, self.max**other)
537
+
538
+ # non-integer exponent
539
+ # 0**neg or neg**frac yields complex
540
+ if (other.is_number or other.is_rational) and (
541
+ self.min.is_extended_nonnegative or (
542
+ other.is_extended_nonnegative and
543
+ self.min.is_extended_nonnegative)):
544
+ num, den = other.as_numer_denom()
545
+ if num is S.One:
546
+ return AccumBounds(*[i**(1/den) for i in self.args])
547
+
548
+ elif den is not S.One: # e.g. if other is not Float
549
+ return (self**num)**(1/den) # ok for non-negative base
550
+
551
+ if isinstance(other, AccumBounds):
552
+ if (self.min.is_extended_positive or
553
+ self.min.is_extended_nonnegative and
554
+ other.min.is_extended_nonnegative):
555
+ p = [self**i for i in other.args]
556
+ if not any(i.is_Pow for i in p):
557
+ a = [j for i in p for j in i.args or (i,)]
558
+ try:
559
+ return self.func(min(a), max(a))
560
+ except TypeError: # can't sort
561
+ pass
562
+
563
+ return Pow(self, other, evaluate=False)
564
+
565
+ return NotImplemented
566
+
567
+ @_sympifyit('other', NotImplemented)
568
+ def __rpow__(self, other):
569
+ if other.is_real and other.is_extended_nonnegative and (
570
+ self.max - self.min).is_extended_positive:
571
+ if other is S.One:
572
+ return S.One
573
+ if other.is_extended_positive:
574
+ a, b = [other**i for i in self.args]
575
+ if min(a, b) != a:
576
+ a, b = b, a
577
+ return self.func(a, b)
578
+ if other.is_zero:
579
+ if self.min.is_zero:
580
+ return self.func(0, 1)
581
+ if self.min.is_extended_positive:
582
+ return S.Zero
583
+
584
+ return Pow(other, self, evaluate=False)
585
+
586
+ def __abs__(self):
587
+ if self.max.is_extended_negative:
588
+ return self.__neg__()
589
+ elif self.min.is_extended_negative:
590
+ return AccumBounds(S.Zero, Max(abs(self.min), self.max))
591
+ else:
592
+ return self
593
+
594
+
595
+ def __contains__(self, other):
596
+ """
597
+ Returns ``True`` if other is contained in self, where other
598
+ belongs to extended real numbers, ``False`` if not contained,
599
+ otherwise TypeError is raised.
600
+
601
+ Examples
602
+ ========
603
+
604
+ >>> from sympy import AccumBounds, oo
605
+ >>> 1 in AccumBounds(-1, 3)
606
+ True
607
+
608
+ -oo and oo go together as limits (in AccumulationBounds).
609
+
610
+ >>> -oo in AccumBounds(1, oo)
611
+ True
612
+
613
+ >>> oo in AccumBounds(-oo, 0)
614
+ True
615
+
616
+ """
617
+ other = _sympify(other)
618
+
619
+ if other in (S.Infinity, S.NegativeInfinity):
620
+ if self.min is S.NegativeInfinity or self.max is S.Infinity:
621
+ return True
622
+ return False
623
+
624
+ rv = And(self.min <= other, self.max >= other)
625
+ if rv not in (True, False):
626
+ raise TypeError("input failed to evaluate")
627
+ return rv
628
+
629
+ def intersection(self, other):
630
+ """
631
+ Returns the intersection of 'self' and 'other'.
632
+ Here other can be an instance of :py:class:`~.FiniteSet` or AccumulationBounds.
633
+
634
+ Parameters
635
+ ==========
636
+
637
+ other : AccumulationBounds
638
+ Another AccumulationBounds object with which the intersection
639
+ has to be computed.
640
+
641
+ Returns
642
+ =======
643
+
644
+ AccumulationBounds
645
+ Intersection of ``self`` and ``other``.
646
+
647
+ Examples
648
+ ========
649
+
650
+ >>> from sympy import AccumBounds, FiniteSet
651
+ >>> AccumBounds(1, 3).intersection(AccumBounds(2, 4))
652
+ AccumBounds(2, 3)
653
+
654
+ >>> AccumBounds(1, 3).intersection(AccumBounds(4, 6))
655
+ EmptySet
656
+
657
+ >>> AccumBounds(1, 4).intersection(FiniteSet(1, 2, 5))
658
+ {1, 2}
659
+
660
+ """
661
+ if not isinstance(other, (AccumBounds, FiniteSet)):
662
+ raise TypeError(
663
+ "Input must be AccumulationBounds or FiniteSet object")
664
+
665
+ if isinstance(other, FiniteSet):
666
+ fin_set = S.EmptySet
667
+ for i in other:
668
+ if i in self:
669
+ fin_set = fin_set + FiniteSet(i)
670
+ return fin_set
671
+
672
+ if self.max < other.min or self.min > other.max:
673
+ return S.EmptySet
674
+
675
+ if self.min <= other.min:
676
+ if self.max <= other.max:
677
+ return AccumBounds(other.min, self.max)
678
+ if self.max > other.max:
679
+ return other
680
+
681
+ if other.min <= self.min:
682
+ if other.max < self.max:
683
+ return AccumBounds(self.min, other.max)
684
+ if other.max > self.max:
685
+ return self
686
+
687
+ def union(self, other):
688
+ # TODO : Devise a better method for Union of AccumBounds
689
+ # this method is not actually correct and
690
+ # can be made better
691
+ if not isinstance(other, AccumBounds):
692
+ raise TypeError(
693
+ "Input must be AccumulationBounds or FiniteSet object")
694
+
695
+ if self.min <= other.min and self.max >= other.min:
696
+ return AccumBounds(self.min, Max(self.max, other.max))
697
+
698
+ if other.min <= self.min and other.max >= self.min:
699
+ return AccumBounds(other.min, Max(self.max, other.max))
700
+
701
+
702
+ @dispatch(AccumulationBounds, AccumulationBounds) # type: ignore # noqa:F811
703
+ def _eval_is_le(lhs, rhs): # noqa:F811
704
+ if is_le(lhs.max, rhs.min):
705
+ return True
706
+ if is_gt(lhs.min, rhs.max):
707
+ return False
708
+
709
+
710
+ @dispatch(AccumulationBounds, Basic) # type: ignore # noqa:F811
711
+ def _eval_is_le(lhs, rhs): # noqa: F811
712
+
713
+ """
714
+ Returns ``True `` if range of values attained by ``lhs`` AccumulationBounds
715
+ object is greater than the range of values attained by ``rhs``,
716
+ where ``rhs`` may be any value of type AccumulationBounds object or
717
+ extended real number value, ``False`` if ``rhs`` satisfies
718
+ the same property, else an unevaluated :py:class:`~.Relational`.
719
+
720
+ Examples
721
+ ========
722
+
723
+ >>> from sympy import AccumBounds, oo
724
+ >>> AccumBounds(1, 3) > AccumBounds(4, oo)
725
+ False
726
+ >>> AccumBounds(1, 4) > AccumBounds(3, 4)
727
+ AccumBounds(1, 4) > AccumBounds(3, 4)
728
+ >>> AccumBounds(1, oo) > -1
729
+ True
730
+
731
+ """
732
+ if not rhs.is_extended_real:
733
+ raise TypeError(
734
+ "Invalid comparison of %s %s" %
735
+ (type(rhs), rhs))
736
+ elif rhs.is_comparable:
737
+ if is_le(lhs.max, rhs):
738
+ return True
739
+ if is_gt(lhs.min, rhs):
740
+ return False
741
+
742
+
743
+ @dispatch(AccumulationBounds, AccumulationBounds)
744
+ def _eval_is_ge(lhs, rhs): # noqa:F811
745
+ if is_ge(lhs.min, rhs.max):
746
+ return True
747
+ if is_lt(lhs.max, rhs.min):
748
+ return False
749
+
750
+
751
+ @dispatch(AccumulationBounds, Expr) # type:ignore
752
+ def _eval_is_ge(lhs, rhs): # noqa: F811
753
+ """
754
+ Returns ``True`` if range of values attained by ``lhs`` AccumulationBounds
755
+ object is less that the range of values attained by ``rhs``, where
756
+ other may be any value of type AccumulationBounds object or extended
757
+ real number value, ``False`` if ``rhs`` satisfies the same
758
+ property, else an unevaluated :py:class:`~.Relational`.
759
+
760
+ Examples
761
+ ========
762
+
763
+ >>> from sympy import AccumBounds, oo
764
+ >>> AccumBounds(1, 3) >= AccumBounds(4, oo)
765
+ False
766
+ >>> AccumBounds(1, 4) >= AccumBounds(3, 4)
767
+ AccumBounds(1, 4) >= AccumBounds(3, 4)
768
+ >>> AccumBounds(1, oo) >= 1
769
+ True
770
+ """
771
+
772
+ if not rhs.is_extended_real:
773
+ raise TypeError(
774
+ "Invalid comparison of %s %s" %
775
+ (type(rhs), rhs))
776
+ elif rhs.is_comparable:
777
+ if is_ge(lhs.min, rhs):
778
+ return True
779
+ if is_lt(lhs.max, rhs):
780
+ return False
781
+
782
+
783
+ @dispatch(Expr, AccumulationBounds) # type:ignore
784
+ def _eval_is_ge(lhs, rhs): # noqa:F811
785
+ if not lhs.is_extended_real:
786
+ raise TypeError(
787
+ "Invalid comparison of %s %s" %
788
+ (type(lhs), lhs))
789
+ elif lhs.is_comparable:
790
+ if is_le(rhs.max, lhs):
791
+ return True
792
+ if is_gt(rhs.min, lhs):
793
+ return False
794
+
795
+
796
+ @dispatch(AccumulationBounds, AccumulationBounds) # type:ignore
797
+ def _eval_is_ge(lhs, rhs): # noqa:F811
798
+ if is_ge(lhs.min, rhs.max):
799
+ return True
800
+ if is_lt(lhs.max, rhs.min):
801
+ return False
802
+
803
+ # setting an alias for AccumulationBounds
804
+ AccumBounds = AccumulationBounds
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/finite_diff.py ADDED
@@ -0,0 +1,476 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ Finite difference weights
3
+ =========================
4
+
5
+ This module implements an algorithm for efficient generation of finite
6
+ difference weights for ordinary differentials of functions for
7
+ derivatives from 0 (interpolation) up to arbitrary order.
8
+
9
+ The core algorithm is provided in the finite difference weight generating
10
+ function (``finite_diff_weights``), and two convenience functions are provided
11
+ for:
12
+
13
+ - estimating a derivative (or interpolate) directly from a series of points
14
+ is also provided (``apply_finite_diff``).
15
+ - differentiating by using finite difference approximations
16
+ (``differentiate_finite``).
17
+
18
+ """
19
+
20
+ from sympy.core.function import Derivative
21
+ from sympy.core.singleton import S
22
+ from sympy.core.function import Subs
23
+ from sympy.core.traversal import preorder_traversal
24
+ from sympy.utilities.exceptions import sympy_deprecation_warning
25
+ from sympy.utilities.iterables import iterable
26
+
27
+
28
+
29
+ def finite_diff_weights(order, x_list, x0=S.One):
30
+ """
31
+ Calculates the finite difference weights for an arbitrarily spaced
32
+ one-dimensional grid (``x_list``) for derivatives at ``x0`` of order
33
+ 0, 1, ..., up to ``order`` using a recursive formula. Order of accuracy
34
+ is at least ``len(x_list) - order``, if ``x_list`` is defined correctly.
35
+
36
+ Parameters
37
+ ==========
38
+
39
+ order: int
40
+ Up to what derivative order weights should be calculated.
41
+ 0 corresponds to interpolation.
42
+ x_list: sequence
43
+ Sequence of (unique) values for the independent variable.
44
+ It is useful (but not necessary) to order ``x_list`` from
45
+ nearest to furthest from ``x0``; see examples below.
46
+ x0: Number or Symbol
47
+ Root or value of the independent variable for which the finite
48
+ difference weights should be generated. Default is ``S.One``.
49
+
50
+ Returns
51
+ =======
52
+
53
+ list
54
+ A list of sublists, each corresponding to coefficients for
55
+ increasing derivative order, and each containing lists of
56
+ coefficients for increasing subsets of x_list.
57
+
58
+ Examples
59
+ ========
60
+
61
+ >>> from sympy import finite_diff_weights, S
62
+ >>> res = finite_diff_weights(1, [-S(1)/2, S(1)/2, S(3)/2, S(5)/2], 0)
63
+ >>> res
64
+ [[[1, 0, 0, 0],
65
+ [1/2, 1/2, 0, 0],
66
+ [3/8, 3/4, -1/8, 0],
67
+ [5/16, 15/16, -5/16, 1/16]],
68
+ [[0, 0, 0, 0],
69
+ [-1, 1, 0, 0],
70
+ [-1, 1, 0, 0],
71
+ [-23/24, 7/8, 1/8, -1/24]]]
72
+ >>> res[0][-1] # FD weights for 0th derivative, using full x_list
73
+ [5/16, 15/16, -5/16, 1/16]
74
+ >>> res[1][-1] # FD weights for 1st derivative
75
+ [-23/24, 7/8, 1/8, -1/24]
76
+ >>> res[1][-2] # FD weights for 1st derivative, using x_list[:-1]
77
+ [-1, 1, 0, 0]
78
+ >>> res[1][-1][0] # FD weight for 1st deriv. for x_list[0]
79
+ -23/24
80
+ >>> res[1][-1][1] # FD weight for 1st deriv. for x_list[1], etc.
81
+ 7/8
82
+
83
+ Each sublist contains the most accurate formula at the end.
84
+ Note, that in the above example ``res[1][1]`` is the same as ``res[1][2]``.
85
+ Since res[1][2] has an order of accuracy of
86
+ ``len(x_list[:3]) - order = 3 - 1 = 2``, the same is true for ``res[1][1]``!
87
+
88
+ >>> res = finite_diff_weights(1, [S(0), S(1), -S(1), S(2), -S(2)], 0)[1]
89
+ >>> res
90
+ [[0, 0, 0, 0, 0],
91
+ [-1, 1, 0, 0, 0],
92
+ [0, 1/2, -1/2, 0, 0],
93
+ [-1/2, 1, -1/3, -1/6, 0],
94
+ [0, 2/3, -2/3, -1/12, 1/12]]
95
+ >>> res[0] # no approximation possible, using x_list[0] only
96
+ [0, 0, 0, 0, 0]
97
+ >>> res[1] # classic forward step approximation
98
+ [-1, 1, 0, 0, 0]
99
+ >>> res[2] # classic centered approximation
100
+ [0, 1/2, -1/2, 0, 0]
101
+ >>> res[3:] # higher order approximations
102
+ [[-1/2, 1, -1/3, -1/6, 0], [0, 2/3, -2/3, -1/12, 1/12]]
103
+
104
+ Let us compare this to a differently defined ``x_list``. Pay attention to
105
+ ``foo[i][k]`` corresponding to the gridpoint defined by ``x_list[k]``.
106
+
107
+ >>> foo = finite_diff_weights(1, [-S(2), -S(1), S(0), S(1), S(2)], 0)[1]
108
+ >>> foo
109
+ [[0, 0, 0, 0, 0],
110
+ [-1, 1, 0, 0, 0],
111
+ [1/2, -2, 3/2, 0, 0],
112
+ [1/6, -1, 1/2, 1/3, 0],
113
+ [1/12, -2/3, 0, 2/3, -1/12]]
114
+ >>> foo[1] # not the same and of lower accuracy as res[1]!
115
+ [-1, 1, 0, 0, 0]
116
+ >>> foo[2] # classic double backward step approximation
117
+ [1/2, -2, 3/2, 0, 0]
118
+ >>> foo[4] # the same as res[4]
119
+ [1/12, -2/3, 0, 2/3, -1/12]
120
+
121
+ Note that, unless you plan on using approximations based on subsets of
122
+ ``x_list``, the order of gridpoints does not matter.
123
+
124
+ The capability to generate weights at arbitrary points can be
125
+ used e.g. to minimize Runge's phenomenon by using Chebyshev nodes:
126
+
127
+ >>> from sympy import cos, symbols, pi, simplify
128
+ >>> N, (h, x) = 4, symbols('h x')
129
+ >>> x_list = [x+h*cos(i*pi/(N)) for i in range(N,-1,-1)] # chebyshev nodes
130
+ >>> print(x_list)
131
+ [-h + x, -sqrt(2)*h/2 + x, x, sqrt(2)*h/2 + x, h + x]
132
+ >>> mycoeffs = finite_diff_weights(1, x_list, 0)[1][4]
133
+ >>> [simplify(c) for c in mycoeffs] #doctest: +NORMALIZE_WHITESPACE
134
+ [(h**3/2 + h**2*x - 3*h*x**2 - 4*x**3)/h**4,
135
+ (-sqrt(2)*h**3 - 4*h**2*x + 3*sqrt(2)*h*x**2 + 8*x**3)/h**4,
136
+ (6*h**2*x - 8*x**3)/h**4,
137
+ (sqrt(2)*h**3 - 4*h**2*x - 3*sqrt(2)*h*x**2 + 8*x**3)/h**4,
138
+ (-h**3/2 + h**2*x + 3*h*x**2 - 4*x**3)/h**4]
139
+
140
+ Notes
141
+ =====
142
+
143
+ If weights for a finite difference approximation of 3rd order
144
+ derivative is wanted, weights for 0th, 1st and 2nd order are
145
+ calculated "for free", so are formulae using subsets of ``x_list``.
146
+ This is something one can take advantage of to save computational cost.
147
+ Be aware that one should define ``x_list`` from nearest to furthest from
148
+ ``x0``. If not, subsets of ``x_list`` will yield poorer approximations,
149
+ which might not grand an order of accuracy of ``len(x_list) - order``.
150
+
151
+ See also
152
+ ========
153
+
154
+ sympy.calculus.finite_diff.apply_finite_diff
155
+
156
+ References
157
+ ==========
158
+
159
+ .. [1] Generation of Finite Difference Formulas on Arbitrarily Spaced
160
+ Grids, Bengt Fornberg; Mathematics of computation; 51; 184;
161
+ (1988); 699-706; doi:10.1090/S0025-5718-1988-0935077-0
162
+
163
+ """
164
+ # The notation below closely corresponds to the one used in the paper.
165
+ order = S(order)
166
+ if not order.is_number:
167
+ raise ValueError("Cannot handle symbolic order.")
168
+ if order < 0:
169
+ raise ValueError("Negative derivative order illegal.")
170
+ if int(order) != order:
171
+ raise ValueError("Non-integer order illegal")
172
+ M = order
173
+ N = len(x_list) - 1
174
+ delta = [[[0 for nu in range(N+1)] for n in range(N+1)] for
175
+ m in range(M+1)]
176
+ delta[0][0][0] = S.One
177
+ c1 = S.One
178
+ for n in range(1, N+1):
179
+ c2 = S.One
180
+ for nu in range(n):
181
+ c3 = x_list[n] - x_list[nu]
182
+ c2 = c2 * c3
183
+ if n <= M:
184
+ delta[n][n-1][nu] = 0
185
+ for m in range(min(n, M)+1):
186
+ delta[m][n][nu] = (x_list[n]-x0)*delta[m][n-1][nu] -\
187
+ m*delta[m-1][n-1][nu]
188
+ delta[m][n][nu] /= c3
189
+ for m in range(min(n, M)+1):
190
+ delta[m][n][n] = c1/c2*(m*delta[m-1][n-1][n-1] -
191
+ (x_list[n-1]-x0)*delta[m][n-1][n-1])
192
+ c1 = c2
193
+ return delta
194
+
195
+
196
+ def apply_finite_diff(order, x_list, y_list, x0=S.Zero):
197
+ """
198
+ Calculates the finite difference approximation of
199
+ the derivative of requested order at ``x0`` from points
200
+ provided in ``x_list`` and ``y_list``.
201
+
202
+ Parameters
203
+ ==========
204
+
205
+ order: int
206
+ order of derivative to approximate. 0 corresponds to interpolation.
207
+ x_list: sequence
208
+ Sequence of (unique) values for the independent variable.
209
+ y_list: sequence
210
+ The function value at corresponding values for the independent
211
+ variable in x_list.
212
+ x0: Number or Symbol
213
+ At what value of the independent variable the derivative should be
214
+ evaluated. Defaults to 0.
215
+
216
+ Returns
217
+ =======
218
+
219
+ sympy.core.add.Add or sympy.core.numbers.Number
220
+ The finite difference expression approximating the requested
221
+ derivative order at ``x0``.
222
+
223
+ Examples
224
+ ========
225
+
226
+ >>> from sympy import apply_finite_diff
227
+ >>> cube = lambda arg: (1.0*arg)**3
228
+ >>> xlist = range(-3,3+1)
229
+ >>> apply_finite_diff(2, xlist, map(cube, xlist), 2) - 12 # doctest: +SKIP
230
+ -3.55271367880050e-15
231
+
232
+ we see that the example above only contain rounding errors.
233
+ apply_finite_diff can also be used on more abstract objects:
234
+
235
+ >>> from sympy import IndexedBase, Idx
236
+ >>> x, y = map(IndexedBase, 'xy')
237
+ >>> i = Idx('i')
238
+ >>> x_list, y_list = zip(*[(x[i+j], y[i+j]) for j in range(-1,2)])
239
+ >>> apply_finite_diff(1, x_list, y_list, x[i])
240
+ ((x[i + 1] - x[i])/(-x[i - 1] + x[i]) - 1)*y[i]/(x[i + 1] - x[i]) -
241
+ (x[i + 1] - x[i])*y[i - 1]/((x[i + 1] - x[i - 1])*(-x[i - 1] + x[i])) +
242
+ (-x[i - 1] + x[i])*y[i + 1]/((x[i + 1] - x[i - 1])*(x[i + 1] - x[i]))
243
+
244
+ Notes
245
+ =====
246
+
247
+ Order = 0 corresponds to interpolation.
248
+ Only supply so many points you think makes sense
249
+ to around x0 when extracting the derivative (the function
250
+ need to be well behaved within that region). Also beware
251
+ of Runge's phenomenon.
252
+
253
+ See also
254
+ ========
255
+
256
+ sympy.calculus.finite_diff.finite_diff_weights
257
+
258
+ References
259
+ ==========
260
+
261
+ Fortran 90 implementation with Python interface for numerics: finitediff_
262
+
263
+ .. _finitediff: https://github.com/bjodah/finitediff
264
+
265
+ """
266
+
267
+ # In the original paper the following holds for the notation:
268
+ # M = order
269
+ # N = len(x_list) - 1
270
+
271
+ N = len(x_list) - 1
272
+ if len(x_list) != len(y_list):
273
+ raise ValueError("x_list and y_list not equal in length.")
274
+
275
+ delta = finite_diff_weights(order, x_list, x0)
276
+
277
+ derivative = 0
278
+ for nu in range(len(x_list)):
279
+ derivative += delta[order][N][nu]*y_list[nu]
280
+ return derivative
281
+
282
+
283
+ def _as_finite_diff(derivative, points=1, x0=None, wrt=None):
284
+ """
285
+ Returns an approximation of a derivative of a function in
286
+ the form of a finite difference formula. The expression is a
287
+ weighted sum of the function at a number of discrete values of
288
+ (one of) the independent variable(s).
289
+
290
+ Parameters
291
+ ==========
292
+
293
+ derivative: a Derivative instance
294
+
295
+ points: sequence or coefficient, optional
296
+ If sequence: discrete values (length >= order+1) of the
297
+ independent variable used for generating the finite
298
+ difference weights.
299
+ If it is a coefficient, it will be used as the step-size
300
+ for generating an equidistant sequence of length order+1
301
+ centered around ``x0``. default: 1 (step-size 1)
302
+
303
+ x0: number or Symbol, optional
304
+ the value of the independent variable (``wrt``) at which the
305
+ derivative is to be approximated. Default: same as ``wrt``.
306
+
307
+ wrt: Symbol, optional
308
+ "with respect to" the variable for which the (partial)
309
+ derivative is to be approximated for. If not provided it
310
+ is required that the Derivative is ordinary. Default: ``None``.
311
+
312
+ Examples
313
+ ========
314
+
315
+ >>> from sympy import symbols, Function, exp, sqrt, Symbol
316
+ >>> from sympy.calculus.finite_diff import _as_finite_diff
317
+ >>> x, h = symbols('x h')
318
+ >>> f = Function('f')
319
+ >>> _as_finite_diff(f(x).diff(x))
320
+ -f(x - 1/2) + f(x + 1/2)
321
+
322
+ The default step size and number of points are 1 and ``order + 1``
323
+ respectively. We can change the step size by passing a symbol
324
+ as a parameter:
325
+
326
+ >>> _as_finite_diff(f(x).diff(x), h)
327
+ -f(-h/2 + x)/h + f(h/2 + x)/h
328
+
329
+ We can also specify the discretized values to be used in a sequence:
330
+
331
+ >>> _as_finite_diff(f(x).diff(x), [x, x+h, x+2*h])
332
+ -3*f(x)/(2*h) + 2*f(h + x)/h - f(2*h + x)/(2*h)
333
+
334
+ The algorithm is not restricted to use equidistant spacing, nor
335
+ do we need to make the approximation around ``x0``, but we can get
336
+ an expression estimating the derivative at an offset:
337
+
338
+ >>> e, sq2 = exp(1), sqrt(2)
339
+ >>> xl = [x-h, x+h, x+e*h]
340
+ >>> _as_finite_diff(f(x).diff(x, 1), xl, x+h*sq2)
341
+ 2*h*((h + sqrt(2)*h)/(2*h) - (-sqrt(2)*h + h)/(2*h))*f(E*h + x)/((-h + E*h)*(h + E*h)) +
342
+ (-(-sqrt(2)*h + h)/(2*h) - (-sqrt(2)*h + E*h)/(2*h))*f(-h + x)/(h + E*h) +
343
+ (-(h + sqrt(2)*h)/(2*h) + (-sqrt(2)*h + E*h)/(2*h))*f(h + x)/(-h + E*h)
344
+
345
+ Partial derivatives are also supported:
346
+
347
+ >>> y = Symbol('y')
348
+ >>> d2fdxdy=f(x,y).diff(x,y)
349
+ >>> _as_finite_diff(d2fdxdy, wrt=x)
350
+ -Derivative(f(x - 1/2, y), y) + Derivative(f(x + 1/2, y), y)
351
+
352
+ See also
353
+ ========
354
+
355
+ sympy.calculus.finite_diff.apply_finite_diff
356
+ sympy.calculus.finite_diff.finite_diff_weights
357
+
358
+ """
359
+ if derivative.is_Derivative:
360
+ pass
361
+ elif derivative.is_Atom:
362
+ return derivative
363
+ else:
364
+ return derivative.fromiter(
365
+ [_as_finite_diff(ar, points, x0, wrt) for ar
366
+ in derivative.args], **derivative.assumptions0)
367
+
368
+ if wrt is None:
369
+ old = None
370
+ for v in derivative.variables:
371
+ if old is v:
372
+ continue
373
+ derivative = _as_finite_diff(derivative, points, x0, v)
374
+ old = v
375
+ return derivative
376
+
377
+ order = derivative.variables.count(wrt)
378
+
379
+ if x0 is None:
380
+ x0 = wrt
381
+
382
+ if not iterable(points):
383
+ if getattr(points, 'is_Function', False) and wrt in points.args:
384
+ points = points.subs(wrt, x0)
385
+ # points is simply the step-size, let's make it a
386
+ # equidistant sequence centered around x0
387
+ if order % 2 == 0:
388
+ # even order => odd number of points, grid point included
389
+ points = [x0 + points*i for i
390
+ in range(-order//2, order//2 + 1)]
391
+ else:
392
+ # odd order => even number of points, half-way wrt grid point
393
+ points = [x0 + points*S(i)/2 for i
394
+ in range(-order, order + 1, 2)]
395
+ others = [wrt, 0]
396
+ for v in set(derivative.variables):
397
+ if v == wrt:
398
+ continue
399
+ others += [v, derivative.variables.count(v)]
400
+ if len(points) < order+1:
401
+ raise ValueError("Too few points for order %d" % order)
402
+ return apply_finite_diff(order, points, [
403
+ Derivative(derivative.expr.subs({wrt: x}), *others) for
404
+ x in points], x0)
405
+
406
+
407
+ def differentiate_finite(expr, *symbols,
408
+ points=1, x0=None, wrt=None, evaluate=False):
409
+ r""" Differentiate expr and replace Derivatives with finite differences.
410
+
411
+ Parameters
412
+ ==========
413
+
414
+ expr : expression
415
+ \*symbols : differentiate with respect to symbols
416
+ points: sequence, coefficient or undefined function, optional
417
+ see ``Derivative.as_finite_difference``
418
+ x0: number or Symbol, optional
419
+ see ``Derivative.as_finite_difference``
420
+ wrt: Symbol, optional
421
+ see ``Derivative.as_finite_difference``
422
+
423
+ Examples
424
+ ========
425
+
426
+ >>> from sympy import sin, Function, differentiate_finite
427
+ >>> from sympy.abc import x, y, h
428
+ >>> f, g = Function('f'), Function('g')
429
+ >>> differentiate_finite(f(x)*g(x), x, points=[x-h, x+h])
430
+ -f(-h + x)*g(-h + x)/(2*h) + f(h + x)*g(h + x)/(2*h)
431
+
432
+ ``differentiate_finite`` works on any expression, including the expressions
433
+ with embedded derivatives:
434
+
435
+ >>> differentiate_finite(f(x) + sin(x), x, 2)
436
+ -2*f(x) + f(x - 1) + f(x + 1) - 2*sin(x) + sin(x - 1) + sin(x + 1)
437
+ >>> differentiate_finite(f(x, y), x, y)
438
+ f(x - 1/2, y - 1/2) - f(x - 1/2, y + 1/2) - f(x + 1/2, y - 1/2) + f(x + 1/2, y + 1/2)
439
+ >>> differentiate_finite(f(x)*g(x).diff(x), x)
440
+ (-g(x) + g(x + 1))*f(x + 1/2) - (g(x) - g(x - 1))*f(x - 1/2)
441
+
442
+ To make finite difference with non-constant discretization step use
443
+ undefined functions:
444
+
445
+ >>> dx = Function('dx')
446
+ >>> differentiate_finite(f(x)*g(x).diff(x), points=dx(x))
447
+ -(-g(x - dx(x)/2 - dx(x - dx(x)/2)/2)/dx(x - dx(x)/2) +
448
+ g(x - dx(x)/2 + dx(x - dx(x)/2)/2)/dx(x - dx(x)/2))*f(x - dx(x)/2)/dx(x) +
449
+ (-g(x + dx(x)/2 - dx(x + dx(x)/2)/2)/dx(x + dx(x)/2) +
450
+ g(x + dx(x)/2 + dx(x + dx(x)/2)/2)/dx(x + dx(x)/2))*f(x + dx(x)/2)/dx(x)
451
+
452
+ """
453
+ if any(term.is_Derivative for term in list(preorder_traversal(expr))):
454
+ evaluate = False
455
+
456
+ Dexpr = expr.diff(*symbols, evaluate=evaluate)
457
+ if evaluate:
458
+ sympy_deprecation_warning("""
459
+ The evaluate flag to differentiate_finite() is deprecated.
460
+
461
+ evaluate=True expands the intermediate derivatives before computing
462
+ differences, but this usually not what you want, as it does not
463
+ satisfy the product rule.
464
+ """,
465
+ deprecated_since_version="1.5",
466
+ active_deprecations_target="deprecated-differentiate_finite-evaluate",
467
+ )
468
+ return Dexpr.replace(
469
+ lambda arg: arg.is_Derivative,
470
+ lambda arg: arg.as_finite_difference(points=points, x0=x0, wrt=wrt))
471
+ else:
472
+ DFexpr = Dexpr.as_finite_difference(points=points, x0=x0, wrt=wrt)
473
+ return DFexpr.replace(
474
+ lambda arg: isinstance(arg, Subs),
475
+ lambda arg: arg.expr.as_finite_difference(
476
+ points=points, x0=arg.point[0], wrt=arg.variables[0]))
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infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/tests/test_accumulationbounds.py ADDED
@@ -0,0 +1,336 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.numbers import (E, Rational, oo, pi, zoo)
2
+ from sympy.core.singleton import S
3
+ from sympy.core.symbol import Symbol
4
+ from sympy.functions.elementary.exponential import (exp, log)
5
+ from sympy.functions.elementary.miscellaneous import (Max, Min, sqrt)
6
+ from sympy.functions.elementary.trigonometric import (cos, sin, tan)
7
+ from sympy.calculus.accumulationbounds import AccumBounds
8
+ from sympy.core import Add, Mul, Pow
9
+ from sympy.core.expr import unchanged
10
+ from sympy.testing.pytest import raises, XFAIL
11
+ from sympy.abc import x
12
+
13
+ a = Symbol('a', real=True)
14
+ B = AccumBounds
15
+
16
+
17
+ def test_AccumBounds():
18
+ assert B(1, 2).args == (1, 2)
19
+ assert B(1, 2).delta is S.One
20
+ assert B(1, 2).mid == Rational(3, 2)
21
+ assert B(1, 3).is_real == True
22
+
23
+ assert B(1, 1) is S.One
24
+
25
+ assert B(1, 2) + 1 == B(2, 3)
26
+ assert 1 + B(1, 2) == B(2, 3)
27
+ assert B(1, 2) + B(2, 3) == B(3, 5)
28
+
29
+ assert -B(1, 2) == B(-2, -1)
30
+
31
+ assert B(1, 2) - 1 == B(0, 1)
32
+ assert 1 - B(1, 2) == B(-1, 0)
33
+ assert B(2, 3) - B(1, 2) == B(0, 2)
34
+
35
+ assert x + B(1, 2) == Add(B(1, 2), x)
36
+ assert a + B(1, 2) == B(1 + a, 2 + a)
37
+ assert B(1, 2) - x == Add(B(1, 2), -x)
38
+
39
+ assert B(-oo, 1) + oo == B(-oo, oo)
40
+ assert B(1, oo) + oo is oo
41
+ assert B(1, oo) - oo == B(-oo, oo)
42
+ assert (-oo - B(-1, oo)) is -oo
43
+ assert B(-oo, 1) - oo is -oo
44
+
45
+ assert B(1, oo) - oo == B(-oo, oo)
46
+ assert B(-oo, 1) - (-oo) == B(-oo, oo)
47
+ assert (oo - B(1, oo)) == B(-oo, oo)
48
+ assert (-oo - B(1, oo)) is -oo
49
+
50
+ assert B(1, 2)/2 == B(S.Half, 1)
51
+ assert 2/B(2, 3) == B(Rational(2, 3), 1)
52
+ assert 1/B(-1, 1) == B(-oo, oo)
53
+
54
+ assert abs(B(1, 2)) == B(1, 2)
55
+ assert abs(B(-2, -1)) == B(1, 2)
56
+ assert abs(B(-2, 1)) == B(0, 2)
57
+ assert abs(B(-1, 2)) == B(0, 2)
58
+ c = Symbol('c')
59
+ raises(ValueError, lambda: B(0, c))
60
+ raises(ValueError, lambda: B(1, -1))
61
+ r = Symbol('r', real=True)
62
+ raises(ValueError, lambda: B(r, r - 1))
63
+
64
+
65
+ def test_AccumBounds_mul():
66
+ assert B(1, 2)*2 == B(2, 4)
67
+ assert 2*B(1, 2) == B(2, 4)
68
+ assert B(1, 2)*B(2, 3) == B(2, 6)
69
+ assert B(0, 2)*B(2, oo) == B(0, oo)
70
+ l, r = B(-oo, oo), B(-a, a)
71
+ assert l*r == B(-oo, oo)
72
+ assert r*l == B(-oo, oo)
73
+ l, r = B(1, oo), B(-3, -2)
74
+ assert l*r == B(-oo, -2)
75
+ assert r*l == B(-oo, -2)
76
+ assert B(1, 2)*0 == 0
77
+ assert B(1, oo)*0 == B(0, oo)
78
+ assert B(-oo, 1)*0 == B(-oo, 0)
79
+ assert B(-oo, oo)*0 == B(-oo, oo)
80
+
81
+ assert B(1, 2)*x == Mul(B(1, 2), x, evaluate=False)
82
+
83
+ assert B(0, 2)*oo == B(0, oo)
84
+ assert B(-2, 0)*oo == B(-oo, 0)
85
+ assert B(0, 2)*(-oo) == B(-oo, 0)
86
+ assert B(-2, 0)*(-oo) == B(0, oo)
87
+ assert B(-1, 1)*oo == B(-oo, oo)
88
+ assert B(-1, 1)*(-oo) == B(-oo, oo)
89
+ assert B(-oo, oo)*oo == B(-oo, oo)
90
+
91
+
92
+ def test_AccumBounds_div():
93
+ assert B(-1, 3)/B(3, 4) == B(Rational(-1, 3), 1)
94
+ assert B(-2, 4)/B(-3, 4) == B(-oo, oo)
95
+ assert B(-3, -2)/B(-4, 0) == B(S.Half, oo)
96
+
97
+ # these two tests can have a better answer
98
+ # after Union of B is improved
99
+ assert B(-3, -2)/B(-2, 1) == B(-oo, oo)
100
+ assert B(2, 3)/B(-2, 2) == B(-oo, oo)
101
+
102
+ assert B(-3, -2)/B(0, 4) == B(-oo, Rational(-1, 2))
103
+ assert B(2, 4)/B(-3, 0) == B(-oo, Rational(-2, 3))
104
+ assert B(2, 4)/B(0, 3) == B(Rational(2, 3), oo)
105
+
106
+ assert B(0, 1)/B(0, 1) == B(0, oo)
107
+ assert B(-1, 0)/B(0, 1) == B(-oo, 0)
108
+ assert B(-1, 2)/B(-2, 2) == B(-oo, oo)
109
+
110
+ assert 1/B(-1, 2) == B(-oo, oo)
111
+ assert 1/B(0, 2) == B(S.Half, oo)
112
+ assert (-1)/B(0, 2) == B(-oo, Rational(-1, 2))
113
+ assert 1/B(-oo, 0) == B(-oo, 0)
114
+ assert 1/B(-1, 0) == B(-oo, -1)
115
+ assert (-2)/B(-oo, 0) == B(0, oo)
116
+ assert 1/B(-oo, -1) == B(-1, 0)
117
+
118
+ assert B(1, 2)/a == Mul(B(1, 2), 1/a, evaluate=False)
119
+
120
+ assert B(1, 2)/0 == B(1, 2)*zoo
121
+ assert B(1, oo)/oo == B(0, oo)
122
+ assert B(1, oo)/(-oo) == B(-oo, 0)
123
+ assert B(-oo, -1)/oo == B(-oo, 0)
124
+ assert B(-oo, -1)/(-oo) == B(0, oo)
125
+ assert B(-oo, oo)/oo == B(-oo, oo)
126
+ assert B(-oo, oo)/(-oo) == B(-oo, oo)
127
+ assert B(-1, oo)/oo == B(0, oo)
128
+ assert B(-1, oo)/(-oo) == B(-oo, 0)
129
+ assert B(-oo, 1)/oo == B(-oo, 0)
130
+ assert B(-oo, 1)/(-oo) == B(0, oo)
131
+
132
+
133
+ def test_issue_18795():
134
+ r = Symbol('r', real=True)
135
+ a = B(-1,1)
136
+ c = B(7, oo)
137
+ b = B(-oo, oo)
138
+ assert c - tan(r) == B(7-tan(r), oo)
139
+ assert b + tan(r) == B(-oo, oo)
140
+ assert (a + r)/a == B(-oo, oo)*B(r - 1, r + 1)
141
+ assert (b + a)/a == B(-oo, oo)
142
+
143
+
144
+ def test_AccumBounds_func():
145
+ assert (x**2 + 2*x + 1).subs(x, B(-1, 1)) == B(-1, 4)
146
+ assert exp(B(0, 1)) == B(1, E)
147
+ assert exp(B(-oo, oo)) == B(0, oo)
148
+ assert log(B(3, 6)) == B(log(3), log(6))
149
+
150
+
151
+ @XFAIL
152
+ def test_AccumBounds_powf():
153
+ nn = Symbol('nn', nonnegative=True)
154
+ assert B(1 + nn, 2 + nn)**B(1, 2) == B(1 + nn, (2 + nn)**2)
155
+ i = Symbol('i', integer=True, negative=True)
156
+ assert B(1, 2)**i == B(2**i, 1)
157
+
158
+
159
+ def test_AccumBounds_pow():
160
+ assert B(0, 2)**2 == B(0, 4)
161
+ assert B(-1, 1)**2 == B(0, 1)
162
+ assert B(1, 2)**2 == B(1, 4)
163
+ assert B(-1, 2)**3 == B(-1, 8)
164
+ assert B(-1, 1)**0 == 1
165
+
166
+ assert B(1, 2)**Rational(5, 2) == B(1, 4*sqrt(2))
167
+ assert B(0, 2)**S.Half == B(0, sqrt(2))
168
+
169
+ neg = Symbol('neg', negative=True)
170
+ assert unchanged(Pow, B(neg, 1), S.Half)
171
+ nn = Symbol('nn', nonnegative=True)
172
+ assert B(nn, nn + 1)**S.Half == B(sqrt(nn), sqrt(nn + 1))
173
+ assert B(nn, nn + 1)**nn == B(nn**nn, (nn + 1)**nn)
174
+ assert unchanged(Pow, B(nn, nn + 1), x)
175
+ i = Symbol('i', integer=True)
176
+ assert B(1, 2)**i == B(Min(1, 2**i), Max(1, 2**i))
177
+ i = Symbol('i', integer=True, nonnegative=True)
178
+ assert B(1, 2)**i == B(1, 2**i)
179
+ assert B(0, 1)**i == B(0**i, 1)
180
+
181
+ assert B(1, 5)**(-2) == B(Rational(1, 25), 1)
182
+ assert B(-1, 3)**(-2) == B(0, oo)
183
+ assert B(0, 2)**(-3) == B(Rational(1, 8), oo)
184
+ assert B(-2, 0)**(-3) == B(-oo, -Rational(1, 8))
185
+ assert B(0, 2)**(-2) == B(Rational(1, 4), oo)
186
+ assert B(-1, 2)**(-3) == B(-oo, oo)
187
+ assert B(-3, -2)**(-3) == B(Rational(-1, 8), Rational(-1, 27))
188
+ assert B(-3, -2)**(-2) == B(Rational(1, 9), Rational(1, 4))
189
+ assert B(0, oo)**S.Half == B(0, oo)
190
+ assert B(-oo, 0)**(-2) == B(0, oo)
191
+ assert B(-2, 0)**(-2) == B(Rational(1, 4), oo)
192
+
193
+ assert B(Rational(1, 3), S.Half)**oo is S.Zero
194
+ assert B(0, S.Half)**oo is S.Zero
195
+ assert B(S.Half, 1)**oo == B(0, oo)
196
+ assert B(0, 1)**oo == B(0, oo)
197
+ assert B(2, 3)**oo is oo
198
+ assert B(1, 2)**oo == B(0, oo)
199
+ assert B(S.Half, 3)**oo == B(0, oo)
200
+ assert B(Rational(-1, 3), Rational(-1, 4))**oo is S.Zero
201
+ assert B(-1, Rational(-1, 2))**oo is S.NaN
202
+ assert B(-3, -2)**oo is zoo
203
+ assert B(-2, -1)**oo is S.NaN
204
+ assert B(-2, Rational(-1, 2))**oo is S.NaN
205
+ assert B(Rational(-1, 2), S.Half)**oo is S.Zero
206
+ assert B(Rational(-1, 2), 1)**oo == B(0, oo)
207
+ assert B(Rational(-2, 3), 2)**oo == B(0, oo)
208
+ assert B(-1, 1)**oo == B(-oo, oo)
209
+ assert B(-1, S.Half)**oo == B(-oo, oo)
210
+ assert B(-1, 2)**oo == B(-oo, oo)
211
+ assert B(-2, S.Half)**oo == B(-oo, oo)
212
+
213
+ assert B(1, 2)**x == Pow(B(1, 2), x, evaluate=False)
214
+
215
+ assert B(2, 3)**(-oo) is S.Zero
216
+ assert B(0, 2)**(-oo) == B(0, oo)
217
+ assert B(-1, 2)**(-oo) == B(-oo, oo)
218
+
219
+ assert (tan(x)**sin(2*x)).subs(x, B(0, pi/2)) == \
220
+ Pow(B(-oo, oo), B(0, 1))
221
+
222
+
223
+ def test_AccumBounds_exponent():
224
+ # base is 0
225
+ z = 0**B(a, a + S.Half)
226
+ assert z.subs(a, 0) == B(0, 1)
227
+ assert z.subs(a, 1) == 0
228
+ p = z.subs(a, -1)
229
+ assert p.is_Pow and p.args == (0, B(-1, -S.Half))
230
+ # base > 0
231
+ # when base is 1 the type of bounds does not matter
232
+ assert 1**B(a, a + 1) == 1
233
+ # otherwise we need to know if 0 is in the bounds
234
+ assert S.Half**B(-2, 2) == B(S(1)/4, 4)
235
+ assert 2**B(-2, 2) == B(S(1)/4, 4)
236
+
237
+ # +eps may introduce +oo
238
+ # if there is a negative integer exponent
239
+ assert B(0, 1)**B(S(1)/2, 1) == B(0, 1)
240
+ assert B(0, 1)**B(0, 1) == B(0, 1)
241
+
242
+ # positive bases have positive bounds
243
+ assert B(2, 3)**B(-3, -2) == B(S(1)/27, S(1)/4)
244
+ assert B(2, 3)**B(-3, 2) == B(S(1)/27, 9)
245
+
246
+ # bounds generating imaginary parts unevaluated
247
+ assert unchanged(Pow, B(-1, 1), B(1, 2))
248
+ assert B(0, S(1)/2)**B(1, oo) == B(0, S(1)/2)
249
+ assert B(0, 1)**B(1, oo) == B(0, oo)
250
+ assert B(0, 2)**B(1, oo) == B(0, oo)
251
+ assert B(0, oo)**B(1, oo) == B(0, oo)
252
+ assert B(S(1)/2, 1)**B(1, oo) == B(0, oo)
253
+ assert B(S(1)/2, 1)**B(-oo, -1) == B(0, oo)
254
+ assert B(S(1)/2, 1)**B(-oo, oo) == B(0, oo)
255
+ assert B(S(1)/2, 2)**B(1, oo) == B(0, oo)
256
+ assert B(S(1)/2, 2)**B(-oo, -1) == B(0, oo)
257
+ assert B(S(1)/2, 2)**B(-oo, oo) == B(0, oo)
258
+ assert B(S(1)/2, oo)**B(1, oo) == B(0, oo)
259
+ assert B(S(1)/2, oo)**B(-oo, -1) == B(0, oo)
260
+ assert B(S(1)/2, oo)**B(-oo, oo) == B(0, oo)
261
+ assert B(1, 2)**B(1, oo) == B(0, oo)
262
+ assert B(1, 2)**B(-oo, -1) == B(0, oo)
263
+ assert B(1, 2)**B(-oo, oo) == B(0, oo)
264
+ assert B(1, oo)**B(1, oo) == B(0, oo)
265
+ assert B(1, oo)**B(-oo, -1) == B(0, oo)
266
+ assert B(1, oo)**B(-oo, oo) == B(0, oo)
267
+ assert B(2, oo)**B(1, oo) == B(2, oo)
268
+ assert B(2, oo)**B(-oo, -1) == B(0, S(1)/2)
269
+ assert B(2, oo)**B(-oo, oo) == B(0, oo)
270
+
271
+
272
+ def test_comparison_AccumBounds():
273
+ assert (B(1, 3) < 4) == S.true
274
+ assert (B(1, 3) < -1) == S.false
275
+ assert (B(1, 3) < 2).rel_op == '<'
276
+ assert (B(1, 3) <= 2).rel_op == '<='
277
+
278
+ assert (B(1, 3) > 4) == S.false
279
+ assert (B(1, 3) > -1) == S.true
280
+ assert (B(1, 3) > 2).rel_op == '>'
281
+ assert (B(1, 3) >= 2).rel_op == '>='
282
+
283
+ assert (B(1, 3) < B(4, 6)) == S.true
284
+ assert (B(1, 3) < B(2, 4)).rel_op == '<'
285
+ assert (B(1, 3) < B(-2, 0)) == S.false
286
+
287
+ assert (B(1, 3) <= B(4, 6)) == S.true
288
+ assert (B(1, 3) <= B(-2, 0)) == S.false
289
+
290
+ assert (B(1, 3) > B(4, 6)) == S.false
291
+ assert (B(1, 3) > B(-2, 0)) == S.true
292
+
293
+ assert (B(1, 3) >= B(4, 6)) == S.false
294
+ assert (B(1, 3) >= B(-2, 0)) == S.true
295
+
296
+ # issue 13499
297
+ assert (cos(x) > 0).subs(x, oo) == (B(-1, 1) > 0)
298
+
299
+ c = Symbol('c')
300
+ raises(TypeError, lambda: (B(0, 1) < c))
301
+ raises(TypeError, lambda: (B(0, 1) <= c))
302
+ raises(TypeError, lambda: (B(0, 1) > c))
303
+ raises(TypeError, lambda: (B(0, 1) >= c))
304
+
305
+
306
+ def test_contains_AccumBounds():
307
+ assert (1 in B(1, 2)) == S.true
308
+ raises(TypeError, lambda: a in B(1, 2))
309
+ assert 0 in B(-1, 0)
310
+ raises(TypeError, lambda:
311
+ (cos(1)**2 + sin(1)**2 - 1) in B(-1, 0))
312
+ assert (-oo in B(1, oo)) == S.true
313
+ assert (oo in B(-oo, 0)) == S.true
314
+
315
+ # issue 13159
316
+ assert Mul(0, B(-1, 1)) == Mul(B(-1, 1), 0) == 0
317
+ import itertools
318
+ for perm in itertools.permutations([0, B(-1, 1), x]):
319
+ assert Mul(*perm) == 0
320
+
321
+
322
+ def test_intersection_AccumBounds():
323
+ assert B(0, 3).intersection(B(1, 2)) == B(1, 2)
324
+ assert B(0, 3).intersection(B(1, 4)) == B(1, 3)
325
+ assert B(0, 3).intersection(B(-1, 2)) == B(0, 2)
326
+ assert B(0, 3).intersection(B(-1, 4)) == B(0, 3)
327
+ assert B(0, 1).intersection(B(2, 3)) == S.EmptySet
328
+ raises(TypeError, lambda: B(0, 3).intersection(1))
329
+
330
+
331
+ def test_union_AccumBounds():
332
+ assert B(0, 3).union(B(1, 2)) == B(0, 3)
333
+ assert B(0, 3).union(B(1, 4)) == B(0, 4)
334
+ assert B(0, 3).union(B(-1, 2)) == B(-1, 3)
335
+ assert B(0, 3).union(B(-1, 4)) == B(-1, 4)
336
+ raises(TypeError, lambda: B(0, 3).union(1))
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/tests/test_euler.py ADDED
@@ -0,0 +1,74 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.function import (Derivative as D, Function)
2
+ from sympy.core.relational import Eq
3
+ from sympy.core.symbol import (Symbol, symbols)
4
+ from sympy.functions.elementary.trigonometric import (cos, sin)
5
+ from sympy.testing.pytest import raises
6
+ from sympy.calculus.euler import euler_equations as euler
7
+
8
+
9
+ def test_euler_interface():
10
+ x = Function('x')
11
+ y = Symbol('y')
12
+ t = Symbol('t')
13
+ raises(TypeError, lambda: euler())
14
+ raises(TypeError, lambda: euler(D(x(t), t)*y(t), [x(t), y]))
15
+ raises(ValueError, lambda: euler(D(x(t), t)*x(y), [x(t), x(y)]))
16
+ raises(TypeError, lambda: euler(D(x(t), t)**2, x(0)))
17
+ raises(TypeError, lambda: euler(D(x(t), t)*y(t), [t]))
18
+ assert euler(D(x(t), t)**2/2, {x(t)}) == [Eq(-D(x(t), t, t), 0)]
19
+ assert euler(D(x(t), t)**2/2, x(t), {t}) == [Eq(-D(x(t), t, t), 0)]
20
+
21
+
22
+ def test_euler_pendulum():
23
+ x = Function('x')
24
+ t = Symbol('t')
25
+ L = D(x(t), t)**2/2 + cos(x(t))
26
+ assert euler(L, x(t), t) == [Eq(-sin(x(t)) - D(x(t), t, t), 0)]
27
+
28
+
29
+ def test_euler_henonheiles():
30
+ x = Function('x')
31
+ y = Function('y')
32
+ t = Symbol('t')
33
+ L = sum(D(z(t), t)**2/2 - z(t)**2/2 for z in [x, y])
34
+ L += -x(t)**2*y(t) + y(t)**3/3
35
+ assert euler(L, [x(t), y(t)], t) == [Eq(-2*x(t)*y(t) - x(t) -
36
+ D(x(t), t, t), 0),
37
+ Eq(-x(t)**2 + y(t)**2 -
38
+ y(t) - D(y(t), t, t), 0)]
39
+
40
+
41
+ def test_euler_sineg():
42
+ psi = Function('psi')
43
+ t = Symbol('t')
44
+ x = Symbol('x')
45
+ L = D(psi(t, x), t)**2/2 - D(psi(t, x), x)**2/2 + cos(psi(t, x))
46
+ assert euler(L, psi(t, x), [t, x]) == [Eq(-sin(psi(t, x)) -
47
+ D(psi(t, x), t, t) +
48
+ D(psi(t, x), x, x), 0)]
49
+
50
+
51
+ def test_euler_high_order():
52
+ # an example from hep-th/0309038
53
+ m = Symbol('m')
54
+ k = Symbol('k')
55
+ x = Function('x')
56
+ y = Function('y')
57
+ t = Symbol('t')
58
+ L = (m*D(x(t), t)**2/2 + m*D(y(t), t)**2/2 -
59
+ k*D(x(t), t)*D(y(t), t, t) + k*D(y(t), t)*D(x(t), t, t))
60
+ assert euler(L, [x(t), y(t)]) == [Eq(2*k*D(y(t), t, t, t) -
61
+ m*D(x(t), t, t), 0),
62
+ Eq(-2*k*D(x(t), t, t, t) -
63
+ m*D(y(t), t, t), 0)]
64
+
65
+ w = Symbol('w')
66
+ L = D(x(t, w), t, w)**2/2
67
+ assert euler(L) == [Eq(D(x(t, w), t, t, w, w), 0)]
68
+
69
+ def test_issue_18653():
70
+ x, y, z = symbols("x y z")
71
+ f, g, h = symbols("f g h", cls=Function, args=(x, y))
72
+ f, g, h = f(), g(), h()
73
+ expr2 = f.diff(x)*h.diff(z)
74
+ assert euler(expr2, (f,), (x, y)) == []
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/tests/test_finite_diff.py ADDED
@@ -0,0 +1,168 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from itertools import product
2
+
3
+ from sympy.core.function import (Function, diff)
4
+ from sympy.core.numbers import Rational
5
+ from sympy.core.singleton import S
6
+ from sympy.core.symbol import symbols
7
+ from sympy.functions.elementary.exponential import exp
8
+ from sympy.calculus.finite_diff import (
9
+ apply_finite_diff, differentiate_finite, finite_diff_weights,
10
+ _as_finite_diff
11
+ )
12
+ from sympy.testing.pytest import raises, warns_deprecated_sympy
13
+
14
+
15
+ def test_apply_finite_diff():
16
+ x, h = symbols('x h')
17
+ f = Function('f')
18
+ assert (apply_finite_diff(1, [x-h, x+h], [f(x-h), f(x+h)], x) -
19
+ (f(x+h)-f(x-h))/(2*h)).simplify() == 0
20
+
21
+ assert (apply_finite_diff(1, [5, 6, 7], [f(5), f(6), f(7)], 5) -
22
+ (Rational(-3, 2)*f(5) + 2*f(6) - S.Half*f(7))).simplify() == 0
23
+ raises(ValueError, lambda: apply_finite_diff(1, [x, h], [f(x)]))
24
+
25
+
26
+ def test_finite_diff_weights():
27
+
28
+ d = finite_diff_weights(1, [5, 6, 7], 5)
29
+ assert d[1][2] == [Rational(-3, 2), 2, Rational(-1, 2)]
30
+
31
+ # Table 1, p. 702 in doi:10.1090/S0025-5718-1988-0935077-0
32
+ # --------------------------------------------------------
33
+ xl = [0, 1, -1, 2, -2, 3, -3, 4, -4]
34
+
35
+ # d holds all coefficients
36
+ d = finite_diff_weights(4, xl, S.Zero)
37
+
38
+ # Zeroeth derivative
39
+ for i in range(5):
40
+ assert d[0][i] == [S.One] + [S.Zero]*8
41
+
42
+ # First derivative
43
+ assert d[1][0] == [S.Zero]*9
44
+ assert d[1][2] == [S.Zero, S.Half, Rational(-1, 2)] + [S.Zero]*6
45
+ assert d[1][4] == [S.Zero, Rational(2, 3), Rational(-2, 3), Rational(-1, 12), Rational(1, 12)] + [S.Zero]*4
46
+ assert d[1][6] == [S.Zero, Rational(3, 4), Rational(-3, 4), Rational(-3, 20), Rational(3, 20),
47
+ Rational(1, 60), Rational(-1, 60)] + [S.Zero]*2
48
+ assert d[1][8] == [S.Zero, Rational(4, 5), Rational(-4, 5), Rational(-1, 5), Rational(1, 5),
49
+ Rational(4, 105), Rational(-4, 105), Rational(-1, 280), Rational(1, 280)]
50
+
51
+ # Second derivative
52
+ for i in range(2):
53
+ assert d[2][i] == [S.Zero]*9
54
+ assert d[2][2] == [-S(2), S.One, S.One] + [S.Zero]*6
55
+ assert d[2][4] == [Rational(-5, 2), Rational(4, 3), Rational(4, 3), Rational(-1, 12), Rational(-1, 12)] + [S.Zero]*4
56
+ assert d[2][6] == [Rational(-49, 18), Rational(3, 2), Rational(3, 2), Rational(-3, 20), Rational(-3, 20),
57
+ Rational(1, 90), Rational(1, 90)] + [S.Zero]*2
58
+ assert d[2][8] == [Rational(-205, 72), Rational(8, 5), Rational(8, 5), Rational(-1, 5), Rational(-1, 5),
59
+ Rational(8, 315), Rational(8, 315), Rational(-1, 560), Rational(-1, 560)]
60
+
61
+ # Third derivative
62
+ for i in range(3):
63
+ assert d[3][i] == [S.Zero]*9
64
+ assert d[3][4] == [S.Zero, -S.One, S.One, S.Half, Rational(-1, 2)] + [S.Zero]*4
65
+ assert d[3][6] == [S.Zero, Rational(-13, 8), Rational(13, 8), S.One, -S.One,
66
+ Rational(-1, 8), Rational(1, 8)] + [S.Zero]*2
67
+ assert d[3][8] == [S.Zero, Rational(-61, 30), Rational(61, 30), Rational(169, 120), Rational(-169, 120),
68
+ Rational(-3, 10), Rational(3, 10), Rational(7, 240), Rational(-7, 240)]
69
+
70
+ # Fourth derivative
71
+ for i in range(4):
72
+ assert d[4][i] == [S.Zero]*9
73
+ assert d[4][4] == [S(6), -S(4), -S(4), S.One, S.One] + [S.Zero]*4
74
+ assert d[4][6] == [Rational(28, 3), Rational(-13, 2), Rational(-13, 2), S(2), S(2),
75
+ Rational(-1, 6), Rational(-1, 6)] + [S.Zero]*2
76
+ assert d[4][8] == [Rational(91, 8), Rational(-122, 15), Rational(-122, 15), Rational(169, 60), Rational(169, 60),
77
+ Rational(-2, 5), Rational(-2, 5), Rational(7, 240), Rational(7, 240)]
78
+
79
+ # Table 2, p. 703 in doi:10.1090/S0025-5718-1988-0935077-0
80
+ # --------------------------------------------------------
81
+ xl = [[j/S(2) for j in list(range(-i*2+1, 0, 2))+list(range(1, i*2+1, 2))]
82
+ for i in range(1, 5)]
83
+
84
+ # d holds all coefficients
85
+ d = [finite_diff_weights({0: 1, 1: 2, 2: 4, 3: 4}[i], xl[i], 0) for
86
+ i in range(4)]
87
+
88
+ # Zeroth derivative
89
+ assert d[0][0][1] == [S.Half, S.Half]
90
+ assert d[1][0][3] == [Rational(-1, 16), Rational(9, 16), Rational(9, 16), Rational(-1, 16)]
91
+ assert d[2][0][5] == [Rational(3, 256), Rational(-25, 256), Rational(75, 128), Rational(75, 128),
92
+ Rational(-25, 256), Rational(3, 256)]
93
+ assert d[3][0][7] == [Rational(-5, 2048), Rational(49, 2048), Rational(-245, 2048), Rational(1225, 2048),
94
+ Rational(1225, 2048), Rational(-245, 2048), Rational(49, 2048), Rational(-5, 2048)]
95
+
96
+ # First derivative
97
+ assert d[0][1][1] == [-S.One, S.One]
98
+ assert d[1][1][3] == [Rational(1, 24), Rational(-9, 8), Rational(9, 8), Rational(-1, 24)]
99
+ assert d[2][1][5] == [Rational(-3, 640), Rational(25, 384), Rational(-75, 64),
100
+ Rational(75, 64), Rational(-25, 384), Rational(3, 640)]
101
+ assert d[3][1][7] == [Rational(5, 7168), Rational(-49, 5120),
102
+ Rational(245, 3072), Rational(-1225, 1024),
103
+ Rational(1225, 1024), Rational(-245, 3072),
104
+ Rational(49, 5120), Rational(-5, 7168)]
105
+
106
+ # Reasonably the rest of the table is also correct... (testing of that
107
+ # deemed excessive at the moment)
108
+ raises(ValueError, lambda: finite_diff_weights(-1, [1, 2]))
109
+ raises(ValueError, lambda: finite_diff_weights(1.2, [1, 2]))
110
+ x = symbols('x')
111
+ raises(ValueError, lambda: finite_diff_weights(x, [1, 2]))
112
+
113
+
114
+ def test_as_finite_diff():
115
+ x = symbols('x')
116
+ f = Function('f')
117
+ dx = Function('dx')
118
+
119
+ _as_finite_diff(f(x).diff(x), [x-2, x-1, x, x+1, x+2])
120
+
121
+ # Use of undefined functions in ``points``
122
+ df_true = -f(x+dx(x)/2-dx(x+dx(x)/2)/2) / dx(x+dx(x)/2) \
123
+ + f(x+dx(x)/2+dx(x+dx(x)/2)/2) / dx(x+dx(x)/2)
124
+ df_test = diff(f(x), x).as_finite_difference(points=dx(x), x0=x+dx(x)/2)
125
+ assert (df_test - df_true).simplify() == 0
126
+
127
+
128
+ def test_differentiate_finite():
129
+ x, y, h = symbols('x y h')
130
+ f = Function('f')
131
+ with warns_deprecated_sympy():
132
+ res0 = differentiate_finite(f(x, y) + exp(42), x, y, evaluate=True)
133
+ xm, xp, ym, yp = [v + sign*S.Half for v, sign in product([x, y], [-1, 1])]
134
+ ref0 = f(xm, ym) + f(xp, yp) - f(xm, yp) - f(xp, ym)
135
+ assert (res0 - ref0).simplify() == 0
136
+
137
+ g = Function('g')
138
+ with warns_deprecated_sympy():
139
+ res1 = differentiate_finite(f(x)*g(x) + 42, x, evaluate=True)
140
+ ref1 = (-f(x - S.Half) + f(x + S.Half))*g(x) + \
141
+ (-g(x - S.Half) + g(x + S.Half))*f(x)
142
+ assert (res1 - ref1).simplify() == 0
143
+
144
+ res2 = differentiate_finite(f(x) + x**3 + 42, x, points=[x-1, x+1])
145
+ ref2 = (f(x + 1) + (x + 1)**3 - f(x - 1) - (x - 1)**3)/2
146
+ assert (res2 - ref2).simplify() == 0
147
+ raises(TypeError, lambda: differentiate_finite(f(x)*g(x), x,
148
+ pints=[x-1, x+1]))
149
+
150
+ res3 = differentiate_finite(f(x)*g(x).diff(x), x)
151
+ ref3 = (-g(x) + g(x + 1))*f(x + S.Half) - (g(x) - g(x - 1))*f(x - S.Half)
152
+ assert res3 == ref3
153
+
154
+ res4 = differentiate_finite(f(x)*g(x).diff(x).diff(x), x)
155
+ ref4 = -((g(x - Rational(3, 2)) - 2*g(x - S.Half) + g(x + S.Half))*f(x - S.Half)) \
156
+ + (g(x - S.Half) - 2*g(x + S.Half) + g(x + Rational(3, 2)))*f(x + S.Half)
157
+ assert res4 == ref4
158
+
159
+ res5_expr = f(x).diff(x)*g(x).diff(x)
160
+ res5 = differentiate_finite(res5_expr, points=[x-h, x, x+h])
161
+ ref5 = (-2*f(x)/h + f(-h + x)/(2*h) + 3*f(h + x)/(2*h))*(-2*g(x)/h + g(-h + x)/(2*h) \
162
+ + 3*g(h + x)/(2*h))/(2*h) - (2*f(x)/h - 3*f(-h + x)/(2*h) - \
163
+ f(h + x)/(2*h))*(2*g(x)/h - 3*g(-h + x)/(2*h) - g(h + x)/(2*h))/(2*h)
164
+ assert res5 == ref5
165
+
166
+ res6 = res5.limit(h, 0).doit()
167
+ ref6 = diff(res5_expr, x)
168
+ assert res6 == ref6
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/tests/test_singularities.py ADDED
@@ -0,0 +1,122 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.numbers import (I, Rational, pi, oo)
2
+ from sympy.core.singleton import S
3
+ from sympy.core.symbol import Symbol, Dummy
4
+ from sympy.core.function import Lambda
5
+ from sympy.functions.elementary.exponential import (exp, log)
6
+ from sympy.functions.elementary.trigonometric import sec, csc
7
+ from sympy.functions.elementary.hyperbolic import (coth, sech,
8
+ atanh, asech, acoth, acsch)
9
+ from sympy.functions.elementary.miscellaneous import sqrt
10
+ from sympy.calculus.singularities import (
11
+ singularities,
12
+ is_increasing,
13
+ is_strictly_increasing,
14
+ is_decreasing,
15
+ is_strictly_decreasing,
16
+ is_monotonic
17
+ )
18
+ from sympy.sets import Interval, FiniteSet, Union, ImageSet
19
+ from sympy.testing.pytest import raises
20
+ from sympy.abc import x, y
21
+
22
+
23
+ def test_singularities():
24
+ x = Symbol('x')
25
+ assert singularities(x**2, x) == S.EmptySet
26
+ assert singularities(x/(x**2 + 3*x + 2), x) == FiniteSet(-2, -1)
27
+ assert singularities(1/(x**2 + 1), x) == FiniteSet(I, -I)
28
+ assert singularities(x/(x**3 + 1), x) == \
29
+ FiniteSet(-1, (1 - sqrt(3) * I) / 2, (1 + sqrt(3) * I) / 2)
30
+ assert singularities(1/(y**2 + 2*I*y + 1), y) == \
31
+ FiniteSet(-I + sqrt(2)*I, -I - sqrt(2)*I)
32
+ _n = Dummy('n')
33
+ assert singularities(sech(x), x).dummy_eq(Union(
34
+ ImageSet(Lambda(_n, 2*_n*I*pi + I*pi/2), S.Integers),
35
+ ImageSet(Lambda(_n, 2*_n*I*pi + 3*I*pi/2), S.Integers)))
36
+ assert singularities(coth(x), x).dummy_eq(Union(
37
+ ImageSet(Lambda(_n, 2*_n*I*pi + I*pi), S.Integers),
38
+ ImageSet(Lambda(_n, 2*_n*I*pi), S.Integers)))
39
+ assert singularities(atanh(x), x) == FiniteSet(-1, 1)
40
+ assert singularities(acoth(x), x) == FiniteSet(-1, 1)
41
+ assert singularities(asech(x), x) == FiniteSet(0)
42
+ assert singularities(acsch(x), x) == FiniteSet(0)
43
+
44
+ x = Symbol('x', real=True)
45
+ assert singularities(1/(x**2 + 1), x) == S.EmptySet
46
+ assert singularities(exp(1/x), x, S.Reals) == FiniteSet(0)
47
+ assert singularities(exp(1/x), x, Interval(1, 2)) == S.EmptySet
48
+ assert singularities(log((x - 2)**2), x, Interval(1, 3)) == FiniteSet(2)
49
+ raises(NotImplementedError, lambda: singularities(x**-oo, x))
50
+ assert singularities(sec(x), x, Interval(0, 3*pi)) == FiniteSet(
51
+ pi/2, 3*pi/2, 5*pi/2)
52
+ assert singularities(csc(x), x, Interval(0, 3*pi)) == FiniteSet(
53
+ 0, pi, 2*pi, 3*pi)
54
+
55
+
56
+ def test_is_increasing():
57
+ """Test whether is_increasing returns correct value."""
58
+ a = Symbol('a', negative=True)
59
+
60
+ assert is_increasing(x**3 - 3*x**2 + 4*x, S.Reals)
61
+ assert is_increasing(-x**2, Interval(-oo, 0))
62
+ assert not is_increasing(-x**2, Interval(0, oo))
63
+ assert not is_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval(-2, 3))
64
+ assert is_increasing(x**2 + y, Interval(1, oo), x)
65
+ assert is_increasing(-x**2*a, Interval(1, oo), x)
66
+ assert is_increasing(1)
67
+
68
+ assert is_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval(-2, 3)) is False
69
+
70
+
71
+ def test_is_strictly_increasing():
72
+ """Test whether is_strictly_increasing returns correct value."""
73
+ assert is_strictly_increasing(
74
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.Ropen(-oo, -2))
75
+ assert is_strictly_increasing(
76
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.Lopen(3, oo))
77
+ assert not is_strictly_increasing(
78
+ 4*x**3 - 6*x**2 - 72*x + 30, Interval.open(-2, 3))
79
+ assert not is_strictly_increasing(-x**2, Interval(0, oo))
80
+ assert not is_strictly_decreasing(1)
81
+
82
+ assert is_strictly_increasing(4*x**3 - 6*x**2 - 72*x + 30, Interval.open(-2, 3)) is False
83
+
84
+
85
+ def test_is_decreasing():
86
+ """Test whether is_decreasing returns correct value."""
87
+ b = Symbol('b', positive=True)
88
+
89
+ assert is_decreasing(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
90
+ assert is_decreasing(1/(x**2 - 3*x), Interval.open(1.5, 3))
91
+ assert is_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
92
+ assert not is_decreasing(1/(x**2 - 3*x), Interval.Ropen(-oo, Rational(3, 2)))
93
+ assert not is_decreasing(-x**2, Interval(-oo, 0))
94
+ assert not is_decreasing(-x**2*b, Interval(-oo, 0), x)
95
+
96
+
97
+ def test_is_strictly_decreasing():
98
+ """Test whether is_strictly_decreasing returns correct value."""
99
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.Lopen(3, oo))
100
+ assert not is_strictly_decreasing(
101
+ 1/(x**2 - 3*x), Interval.Ropen(-oo, Rational(3, 2)))
102
+ assert not is_strictly_decreasing(-x**2, Interval(-oo, 0))
103
+ assert not is_strictly_decreasing(1)
104
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
105
+ assert is_strictly_decreasing(1/(x**2 - 3*x), Interval.open(1.5, 3))
106
+
107
+
108
+ def test_is_monotonic():
109
+ """Test whether is_monotonic returns correct value."""
110
+ assert is_monotonic(1/(x**2 - 3*x), Interval.open(Rational(3,2), 3))
111
+ assert is_monotonic(1/(x**2 - 3*x), Interval.open(1.5, 3))
112
+ assert is_monotonic(1/(x**2 - 3*x), Interval.Lopen(3, oo))
113
+ assert is_monotonic(x**3 - 3*x**2 + 4*x, S.Reals)
114
+ assert not is_monotonic(-x**2, S.Reals)
115
+ assert is_monotonic(x**2 + y + 1, Interval(1, 2), x)
116
+ raises(NotImplementedError, lambda: is_monotonic(x**2 + y + 1))
117
+
118
+
119
+ def test_issue_23401():
120
+ x = Symbol('x')
121
+ expr = (x + 1)/(-1.0e-3*x**2 + 0.1*x + 0.1)
122
+ assert is_increasing(expr, Interval(1,2), x)
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/tests/test_util.py ADDED
@@ -0,0 +1,392 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.function import Lambda
2
+ from sympy.core.numbers import (E, I, Rational, oo, pi)
3
+ from sympy.core.relational import Eq
4
+ from sympy.core.singleton import S
5
+ from sympy.core.symbol import (Dummy, Symbol)
6
+ from sympy.functions.elementary.complexes import (Abs, re)
7
+ from sympy.functions.elementary.exponential import (exp, log)
8
+ from sympy.functions.elementary.integers import frac
9
+ from sympy.functions.elementary.miscellaneous import sqrt
10
+ from sympy.functions.elementary.piecewise import Piecewise
11
+ from sympy.functions.elementary.trigonometric import (
12
+ cos, cot, csc, sec, sin, tan, asin, acos, atan, acot, asec, acsc)
13
+ from sympy.functions.elementary.hyperbolic import (sinh, cosh, tanh, coth,
14
+ sech, csch, asinh, acosh, atanh, acoth, asech, acsch)
15
+ from sympy.functions.special.gamma_functions import gamma
16
+ from sympy.functions.special.error_functions import expint
17
+ from sympy.matrices.expressions.matexpr import MatrixSymbol
18
+ from sympy.simplify.simplify import simplify
19
+ from sympy.calculus.util import (function_range, continuous_domain, not_empty_in,
20
+ periodicity, lcim, is_convex,
21
+ stationary_points, minimum, maximum)
22
+ from sympy.sets.sets import (Interval, FiniteSet, Complement, Union)
23
+ from sympy.sets.fancysets import ImageSet
24
+ from sympy.sets.conditionset import ConditionSet
25
+ from sympy.testing.pytest import XFAIL, raises, _both_exp_pow, slow
26
+ from sympy.abc import x, y
27
+
28
+ a = Symbol('a', real=True)
29
+
30
+ def test_function_range():
31
+ assert function_range(sin(x), x, Interval(-pi/2, pi/2)
32
+ ) == Interval(-1, 1)
33
+ assert function_range(sin(x), x, Interval(0, pi)
34
+ ) == Interval(0, 1)
35
+ assert function_range(tan(x), x, Interval(0, pi)
36
+ ) == Interval(-oo, oo)
37
+ assert function_range(tan(x), x, Interval(pi/2, pi)
38
+ ) == Interval(-oo, 0)
39
+ assert function_range((x + 3)/(x - 2), x, Interval(-5, 5)
40
+ ) == Union(Interval(-oo, Rational(2, 7)), Interval(Rational(8, 3), oo))
41
+ assert function_range(1/(x**2), x, Interval(-1, 1)
42
+ ) == Interval(1, oo)
43
+ assert function_range(exp(x), x, Interval(-1, 1)
44
+ ) == Interval(exp(-1), exp(1))
45
+ assert function_range(log(x) - x, x, S.Reals
46
+ ) == Interval(-oo, -1)
47
+ assert function_range(sqrt(3*x - 1), x, Interval(0, 2)
48
+ ) == Interval(0, sqrt(5))
49
+ assert function_range(x*(x - 1) - (x**2 - x), x, S.Reals
50
+ ) == FiniteSet(0)
51
+ assert function_range(x*(x - 1) - (x**2 - x) + y, x, S.Reals
52
+ ) == FiniteSet(y)
53
+ assert function_range(sin(x), x, Union(Interval(-5, -3), FiniteSet(4))
54
+ ) == Union(Interval(-sin(3), 1), FiniteSet(sin(4)))
55
+ assert function_range(cos(x), x, Interval(-oo, -4)
56
+ ) == Interval(-1, 1)
57
+ assert function_range(cos(x), x, S.EmptySet) == S.EmptySet
58
+ assert function_range(x/sqrt(x**2+1), x, S.Reals) == Interval.open(-1,1)
59
+ raises(NotImplementedError, lambda : function_range(
60
+ exp(x)*(sin(x) - cos(x))/2 - x, x, S.Reals))
61
+ raises(NotImplementedError, lambda : function_range(
62
+ sin(x) + x, x, S.Reals)) # issue 13273
63
+ raises(NotImplementedError, lambda : function_range(
64
+ log(x), x, S.Integers))
65
+ raises(NotImplementedError, lambda : function_range(
66
+ sin(x)/2, x, S.Naturals))
67
+
68
+
69
+ @slow
70
+ def test_function_range1():
71
+ assert function_range(tan(x)**2 + tan(3*x)**2 + 1, x, S.Reals) == Interval(1,oo)
72
+
73
+
74
+ def test_continuous_domain():
75
+ assert continuous_domain(sin(x), x, Interval(0, 2*pi)) == Interval(0, 2*pi)
76
+ assert continuous_domain(tan(x), x, Interval(0, 2*pi)) == \
77
+ Union(Interval(0, pi/2, False, True), Interval(pi/2, pi*Rational(3, 2), True, True),
78
+ Interval(pi*Rational(3, 2), 2*pi, True, False))
79
+ assert continuous_domain(cot(x), x, Interval(0, 2*pi)) == Union(
80
+ Interval.open(0, pi), Interval.open(pi, 2*pi))
81
+ assert continuous_domain((x - 1)/((x - 1)**2), x, S.Reals) == \
82
+ Union(Interval(-oo, 1, True, True), Interval(1, oo, True, True))
83
+ assert continuous_domain(log(x) + log(4*x - 1), x, S.Reals) == \
84
+ Interval(Rational(1, 4), oo, True, True)
85
+ assert continuous_domain(1/sqrt(x - 3), x, S.Reals) == Interval(3, oo, True, True)
86
+ assert continuous_domain(1/x - 2, x, S.Reals) == \
87
+ Union(Interval.open(-oo, 0), Interval.open(0, oo))
88
+ assert continuous_domain(1/(x**2 - 4) + 2, x, S.Reals) == \
89
+ Union(Interval.open(-oo, -2), Interval.open(-2, 2), Interval.open(2, oo))
90
+ assert continuous_domain((x+1)**pi, x, S.Reals) == Interval(-1, oo)
91
+ assert continuous_domain((x+1)**(pi/2), x, S.Reals) == Interval(-1, oo)
92
+ assert continuous_domain(x**x, x, S.Reals) == Interval(0, oo)
93
+ assert continuous_domain((x+1)**log(x**2), x, S.Reals) == Union(
94
+ Interval.Ropen(-1, 0), Interval.open(0, oo))
95
+ domain = continuous_domain(log(tan(x)**2 + 1), x, S.Reals)
96
+ assert not domain.contains(3*pi/2)
97
+ assert domain.contains(5)
98
+ d = Symbol('d', even=True, zero=False)
99
+ assert continuous_domain(x**(1/d), x, S.Reals) == Interval(0, oo)
100
+ n = Dummy('n')
101
+ assert continuous_domain(1/sin(x), x, S.Reals).dummy_eq(Complement(
102
+ S.Reals, Union(ImageSet(Lambda(n, 2*n*pi + pi), S.Integers),
103
+ ImageSet(Lambda(n, 2*n*pi), S.Integers))))
104
+ assert continuous_domain(sin(x) + cos(x), x, S.Reals) == S.Reals
105
+ assert continuous_domain(asin(x), x, S.Reals) == Interval(-1, 1) # issue #21786
106
+ assert continuous_domain(1/acos(log(x)), x, S.Reals) == Interval.Ropen(exp(-1), E)
107
+ assert continuous_domain(sinh(x)+cosh(x), x, S.Reals) == S.Reals
108
+ assert continuous_domain(tanh(x)+sech(x), x, S.Reals) == S.Reals
109
+ assert continuous_domain(atan(x)+asinh(x), x, S.Reals) == S.Reals
110
+ assert continuous_domain(acosh(x), x, S.Reals) == Interval(1, oo)
111
+ assert continuous_domain(atanh(x), x, S.Reals) == Interval.open(-1, 1)
112
+ assert continuous_domain(atanh(x)+acosh(x), x, S.Reals) == S.EmptySet
113
+ assert continuous_domain(asech(x), x, S.Reals) == Interval.Lopen(0, 1)
114
+ assert continuous_domain(acoth(x), x, S.Reals) == Union(
115
+ Interval.open(-oo, -1), Interval.open(1, oo))
116
+ assert continuous_domain(asec(x), x, S.Reals) == Union(
117
+ Interval(-oo, -1), Interval(1, oo))
118
+ assert continuous_domain(acsc(x), x, S.Reals) == Union(
119
+ Interval(-oo, -1), Interval(1, oo))
120
+ for f in (coth, acsch, csch):
121
+ assert continuous_domain(f(x), x, S.Reals) == Union(
122
+ Interval.open(-oo, 0), Interval.open(0, oo))
123
+ assert continuous_domain(acot(x), x, S.Reals).contains(0) == False
124
+ assert continuous_domain(1/(exp(x) - x), x, S.Reals) == Complement(
125
+ S.Reals, ConditionSet(x, Eq(-x + exp(x), 0), S.Reals))
126
+ assert continuous_domain(frac(x**2), x, Interval(-2,-1)) == Union(
127
+ Interval.open(-2, -sqrt(3)), Interval.open(-sqrt(2), -1),
128
+ Interval.open(-sqrt(3), -sqrt(2)))
129
+ assert continuous_domain(frac(x), x, S.Reals) == Complement(
130
+ S.Reals, S.Integers)
131
+ raises(NotImplementedError, lambda : continuous_domain(
132
+ 1/(x**2+1), x, S.Complexes))
133
+ raises(NotImplementedError, lambda : continuous_domain(
134
+ gamma(x), x, Interval(-5,0)))
135
+ assert continuous_domain(x + gamma(pi), x, S.Reals) == S.Reals
136
+
137
+
138
+ @XFAIL
139
+ def test_continuous_domain_acot():
140
+ acot_cont = Piecewise((pi+acot(x), x<0), (acot(x), True))
141
+ assert continuous_domain(acot_cont, x, S.Reals) == S.Reals
142
+
143
+ @XFAIL
144
+ def test_continuous_domain_gamma():
145
+ assert continuous_domain(gamma(x), x, S.Reals).contains(-1) == False
146
+
147
+ @XFAIL
148
+ def test_continuous_domain_neg_power():
149
+ assert continuous_domain((x-2)**(1-x), x, S.Reals) == Interval.open(2, oo)
150
+
151
+
152
+ def test_not_empty_in():
153
+ assert not_empty_in(FiniteSet(x, 2*x).intersect(Interval(1, 2, True, False)), x) == \
154
+ Interval(S.Half, 2, True, False)
155
+ assert not_empty_in(FiniteSet(x, x**2).intersect(Interval(1, 2)), x) == \
156
+ Union(Interval(-sqrt(2), -1), Interval(1, 2))
157
+ assert not_empty_in(FiniteSet(x**2 + x, x).intersect(Interval(2, 4)), x) == \
158
+ Union(Interval(-sqrt(17)/2 - S.Half, -2),
159
+ Interval(1, Rational(-1, 2) + sqrt(17)/2), Interval(2, 4))
160
+ assert not_empty_in(FiniteSet(x/(x - 1)).intersect(S.Reals), x) == \
161
+ Complement(S.Reals, FiniteSet(1))
162
+ assert not_empty_in(FiniteSet(a/(a - 1)).intersect(S.Reals), a) == \
163
+ Complement(S.Reals, FiniteSet(1))
164
+ assert not_empty_in(FiniteSet((x**2 - 3*x + 2)/(x - 1)).intersect(S.Reals), x) == \
165
+ Complement(S.Reals, FiniteSet(1))
166
+ assert not_empty_in(FiniteSet(3, 4, x/(x - 1)).intersect(Interval(2, 3)), x) == \
167
+ Interval(-oo, oo)
168
+ assert not_empty_in(FiniteSet(4, x/(x - 1)).intersect(Interval(2, 3)), x) == \
169
+ Interval(S(3)/2, 2)
170
+ assert not_empty_in(FiniteSet(x/(x**2 - 1)).intersect(S.Reals), x) == \
171
+ Complement(S.Reals, FiniteSet(-1, 1))
172
+ assert not_empty_in(FiniteSet(x, x**2).intersect(Union(Interval(1, 3, True, True),
173
+ Interval(4, 5))), x) == \
174
+ Union(Interval(-sqrt(5), -2), Interval(-sqrt(3), -1, True, True),
175
+ Interval(1, 3, True, True), Interval(4, 5))
176
+ assert not_empty_in(FiniteSet(1).intersect(Interval(3, 4)), x) == S.EmptySet
177
+ assert not_empty_in(FiniteSet(x**2/(x + 2)).intersect(Interval(1, oo)), x) == \
178
+ Union(Interval(-2, -1, True, False), Interval(2, oo))
179
+ raises(ValueError, lambda: not_empty_in(x))
180
+ raises(ValueError, lambda: not_empty_in(Interval(0, 1), x))
181
+ raises(NotImplementedError,
182
+ lambda: not_empty_in(FiniteSet(x).intersect(S.Reals), x, a))
183
+
184
+
185
+ @_both_exp_pow
186
+ def test_periodicity():
187
+ assert periodicity(sin(2*x), x) == pi
188
+ assert periodicity((-2)*tan(4*x), x) == pi/4
189
+ assert periodicity(sin(x)**2, x) == 2*pi
190
+ assert periodicity(3**tan(3*x), x) == pi/3
191
+ assert periodicity(tan(x)*cos(x), x) == 2*pi
192
+ assert periodicity(sin(x)**(tan(x)), x) == 2*pi
193
+ assert periodicity(tan(x)*sec(x), x) == 2*pi
194
+ assert periodicity(sin(2*x)*cos(2*x) - y, x) == pi/2
195
+ assert periodicity(tan(x) + cot(x), x) == pi
196
+ assert periodicity(sin(x) - cos(2*x), x) == 2*pi
197
+ assert periodicity(sin(x) - 1, x) == 2*pi
198
+ assert periodicity(sin(4*x) + sin(x)*cos(x), x) == pi
199
+ assert periodicity(exp(sin(x)), x) == 2*pi
200
+ assert periodicity(log(cot(2*x)) - sin(cos(2*x)), x) == pi
201
+ assert periodicity(sin(2*x)*exp(tan(x) - csc(2*x)), x) == pi
202
+ assert periodicity(cos(sec(x) - csc(2*x)), x) == 2*pi
203
+ assert periodicity(tan(sin(2*x)), x) == pi
204
+ assert periodicity(2*tan(x)**2, x) == pi
205
+ assert periodicity(sin(x%4), x) == 4
206
+ assert periodicity(sin(x)%4, x) == 2*pi
207
+ assert periodicity(tan((3*x-2)%4), x) == Rational(4, 3)
208
+ assert periodicity((sqrt(2)*(x+1)+x) % 3, x) == 3 / (sqrt(2)+1)
209
+ assert periodicity((x**2+1) % x, x) is None
210
+ assert periodicity(sin(re(x)), x) == 2*pi
211
+ assert periodicity(sin(x)**2 + cos(x)**2, x) is S.Zero
212
+ assert periodicity(tan(x), y) is S.Zero
213
+ assert periodicity(sin(x) + I*cos(x), x) == 2*pi
214
+ assert periodicity(x - sin(2*y), y) == pi
215
+
216
+ assert periodicity(exp(x), x) is None
217
+ assert periodicity(exp(I*x), x) == 2*pi
218
+ assert periodicity(exp(I*a), a) == 2*pi
219
+ assert periodicity(exp(a), a) is None
220
+ assert periodicity(exp(log(sin(a) + I*cos(2*a)), evaluate=False), a) == 2*pi
221
+ assert periodicity(exp(log(sin(2*a) + I*cos(a)), evaluate=False), a) == 2*pi
222
+ assert periodicity(exp(sin(a)), a) == 2*pi
223
+ assert periodicity(exp(2*I*a), a) == pi
224
+ assert periodicity(exp(a + I*sin(a)), a) is None
225
+ assert periodicity(exp(cos(a/2) + sin(a)), a) == 4*pi
226
+ assert periodicity(log(x), x) is None
227
+ assert periodicity(exp(x)**sin(x), x) is None
228
+ assert periodicity(sin(x)**y, y) is None
229
+
230
+ assert periodicity(Abs(sin(Abs(sin(x)))), x) == pi
231
+ assert all(periodicity(Abs(f(x)), x) == pi for f in (
232
+ cos, sin, sec, csc, tan, cot))
233
+ assert periodicity(Abs(sin(tan(x))), x) == pi
234
+ assert periodicity(Abs(sin(sin(x) + tan(x))), x) == 2*pi
235
+ assert periodicity(sin(x) > S.Half, x) == 2*pi
236
+
237
+ assert periodicity(x > 2, x) is None
238
+ assert periodicity(x**3 - x**2 + 1, x) is None
239
+ assert periodicity(Abs(x), x) is None
240
+ assert periodicity(Abs(x**2 - 1), x) is None
241
+
242
+ assert periodicity((x**2 + 4)%2, x) is None
243
+ assert periodicity((E**x)%3, x) is None
244
+
245
+ assert periodicity(sin(expint(1, x))/expint(1, x), x) is None
246
+ # returning `None` for any Piecewise
247
+ p = Piecewise((0, x < -1), (x**2, x <= 1), (log(x), True))
248
+ assert periodicity(p, x) is None
249
+
250
+ m = MatrixSymbol('m', 3, 3)
251
+ raises(NotImplementedError, lambda: periodicity(sin(m), m))
252
+ raises(NotImplementedError, lambda: periodicity(sin(m[0, 0]), m))
253
+ raises(NotImplementedError, lambda: periodicity(sin(m), m[0, 0]))
254
+ raises(NotImplementedError, lambda: periodicity(sin(m[0, 0]), m[0, 0]))
255
+
256
+
257
+ def test_periodicity_check():
258
+ assert periodicity(tan(x), x, check=True) == pi
259
+ assert periodicity(sin(x) + cos(x), x, check=True) == 2*pi
260
+ assert periodicity(sec(x), x) == 2*pi
261
+ assert periodicity(sin(x*y), x) == 2*pi/abs(y)
262
+ assert periodicity(Abs(sec(sec(x))), x) == pi
263
+
264
+
265
+ def test_lcim():
266
+ assert lcim([S.Half, S(2), S(3)]) == 6
267
+ assert lcim([pi/2, pi/4, pi]) == pi
268
+ assert lcim([2*pi, pi/2]) == 2*pi
269
+ assert lcim([S.One, 2*pi]) is None
270
+ assert lcim([S(2) + 2*E, E/3 + Rational(1, 3), S.One + E]) == S(2) + 2*E
271
+
272
+
273
+ def test_is_convex():
274
+ assert is_convex(1/x, x, domain=Interval.open(0, oo)) == True
275
+ assert is_convex(1/x, x, domain=Interval(-oo, 0)) == False
276
+ assert is_convex(x**2, x, domain=Interval(0, oo)) == True
277
+ assert is_convex(1/x**3, x, domain=Interval.Lopen(0, oo)) == True
278
+ assert is_convex(-1/x**3, x, domain=Interval.Ropen(-oo, 0)) == True
279
+ assert is_convex(log(x) ,x) == False
280
+ assert is_convex(x**2+y**2, x, y) == True
281
+ assert is_convex(cos(x) + cos(y), x) == False
282
+ assert is_convex(8*x**2 - 2*y**2, x, y) == False
283
+
284
+
285
+ def test_stationary_points():
286
+ assert stationary_points(sin(x), x, Interval(-pi/2, pi/2)
287
+ ) == {-pi/2, pi/2}
288
+ assert stationary_points(sin(x), x, Interval.Ropen(0, pi/4)
289
+ ) is S.EmptySet
290
+ assert stationary_points(tan(x), x,
291
+ ) is S.EmptySet
292
+ assert stationary_points(sin(x)*cos(x), x, Interval(0, pi)
293
+ ) == {pi/4, pi*Rational(3, 4)}
294
+ assert stationary_points(sec(x), x, Interval(0, pi)
295
+ ) == {0, pi}
296
+ assert stationary_points((x+3)*(x-2), x
297
+ ) == FiniteSet(Rational(-1, 2))
298
+ assert stationary_points((x + 3)/(x - 2), x, Interval(-5, 5)
299
+ ) is S.EmptySet
300
+ assert stationary_points((x**2+3)/(x-2), x
301
+ ) == {2 - sqrt(7), 2 + sqrt(7)}
302
+ assert stationary_points((x**2+3)/(x-2), x, Interval(0, 5)
303
+ ) == {2 + sqrt(7)}
304
+ assert stationary_points(x**4 + x**3 - 5*x**2, x, S.Reals
305
+ ) == FiniteSet(-2, 0, Rational(5, 4))
306
+ assert stationary_points(exp(x), x
307
+ ) is S.EmptySet
308
+ assert stationary_points(log(x) - x, x, S.Reals
309
+ ) == {1}
310
+ assert stationary_points(cos(x), x, Union(Interval(0, 5), Interval(-6, -3))
311
+ ) == {0, -pi, pi}
312
+ assert stationary_points(y, x, S.Reals
313
+ ) == S.Reals
314
+ assert stationary_points(y, x, S.EmptySet) == S.EmptySet
315
+
316
+
317
+ def test_maximum():
318
+ assert maximum(sin(x), x) is S.One
319
+ assert maximum(sin(x), x, Interval(0, 1)) == sin(1)
320
+ assert maximum(tan(x), x) is oo
321
+ assert maximum(tan(x), x, Interval(-pi/4, pi/4)) is S.One
322
+ assert maximum(sin(x)*cos(x), x, S.Reals) == S.Half
323
+ assert simplify(maximum(sin(x)*cos(x), x, Interval(pi*Rational(3, 8), pi*Rational(5, 8)))
324
+ ) == sqrt(2)/4
325
+ assert maximum((x+3)*(x-2), x) is oo
326
+ assert maximum((x+3)*(x-2), x, Interval(-5, 0)) == S(14)
327
+ assert maximum((x+3)/(x-2), x, Interval(-5, 0)) == Rational(2, 7)
328
+ assert simplify(maximum(-x**4-x**3+x**2+10, x)
329
+ ) == 41*sqrt(41)/512 + Rational(5419, 512)
330
+ assert maximum(exp(x), x, Interval(-oo, 2)) == exp(2)
331
+ assert maximum(log(x) - x, x, S.Reals) is S.NegativeOne
332
+ assert maximum(cos(x), x, Union(Interval(0, 5), Interval(-6, -3))
333
+ ) is S.One
334
+ assert maximum(cos(x)-sin(x), x, S.Reals) == sqrt(2)
335
+ assert maximum(y, x, S.Reals) == y
336
+ assert maximum(abs(a**3 + a), a, Interval(0, 2)) == 10
337
+ assert maximum(abs(60*a**3 + 24*a), a, Interval(0, 2)) == 528
338
+ assert maximum(abs(12*a*(5*a**2 + 2)), a, Interval(0, 2)) == 528
339
+ assert maximum(x/sqrt(x**2+1), x, S.Reals) == 1
340
+
341
+ raises(ValueError, lambda : maximum(sin(x), x, S.EmptySet))
342
+ raises(ValueError, lambda : maximum(log(cos(x)), x, S.EmptySet))
343
+ raises(ValueError, lambda : maximum(1/(x**2 + y**2 + 1), x, S.EmptySet))
344
+ raises(ValueError, lambda : maximum(sin(x), sin(x)))
345
+ raises(ValueError, lambda : maximum(sin(x), x*y, S.EmptySet))
346
+ raises(ValueError, lambda : maximum(sin(x), S.One))
347
+
348
+
349
+ def test_minimum():
350
+ assert minimum(sin(x), x) is S.NegativeOne
351
+ assert minimum(sin(x), x, Interval(1, 4)) == sin(4)
352
+ assert minimum(tan(x), x) is -oo
353
+ assert minimum(tan(x), x, Interval(-pi/4, pi/4)) is S.NegativeOne
354
+ assert minimum(sin(x)*cos(x), x, S.Reals) == Rational(-1, 2)
355
+ assert simplify(minimum(sin(x)*cos(x), x, Interval(pi*Rational(3, 8), pi*Rational(5, 8)))
356
+ ) == -sqrt(2)/4
357
+ assert minimum((x+3)*(x-2), x) == Rational(-25, 4)
358
+ assert minimum((x+3)/(x-2), x, Interval(-5, 0)) == Rational(-3, 2)
359
+ assert minimum(x**4-x**3+x**2+10, x) == S(10)
360
+ assert minimum(exp(x), x, Interval(-2, oo)) == exp(-2)
361
+ assert minimum(log(x) - x, x, S.Reals) is -oo
362
+ assert minimum(cos(x), x, Union(Interval(0, 5), Interval(-6, -3))
363
+ ) is S.NegativeOne
364
+ assert minimum(cos(x)-sin(x), x, S.Reals) == -sqrt(2)
365
+ assert minimum(y, x, S.Reals) == y
366
+ assert minimum(x/sqrt(x**2+1), x, S.Reals) == -1
367
+
368
+ raises(ValueError, lambda : minimum(sin(x), x, S.EmptySet))
369
+ raises(ValueError, lambda : minimum(log(cos(x)), x, S.EmptySet))
370
+ raises(ValueError, lambda : minimum(1/(x**2 + y**2 + 1), x, S.EmptySet))
371
+ raises(ValueError, lambda : minimum(sin(x), sin(x)))
372
+ raises(ValueError, lambda : minimum(sin(x), x*y, S.EmptySet))
373
+ raises(ValueError, lambda : minimum(sin(x), S.One))
374
+
375
+
376
+ def test_issue_19869():
377
+ assert (maximum(sqrt(3)*(x - 1)/(3*sqrt(x**2 + 1)), x)
378
+ ) == sqrt(3)/3
379
+
380
+
381
+ def test_issue_16469():
382
+ f = abs(a)
383
+ assert function_range(f, a, S.Reals) == Interval(0, oo, False, True)
384
+
385
+
386
+ @_both_exp_pow
387
+ def test_issue_18747():
388
+ assert periodicity(exp(pi*I*(x/4 + S.Half/2)), x) == 8
389
+
390
+
391
+ def test_issue_25942():
392
+ assert (acos(x) > pi/3).as_set() == Interval.Ropen(-1, S(1)/2)
infer_4_47_1/lib/python3.10/site-packages/sympy/calculus/util.py ADDED
@@ -0,0 +1,905 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from .accumulationbounds import AccumBounds, AccumulationBounds # noqa: F401
2
+ from .singularities import singularities
3
+ from sympy.core import Pow, S
4
+ from sympy.core.function import diff, expand_mul, Function
5
+ from sympy.core.kind import NumberKind
6
+ from sympy.core.mod import Mod
7
+ from sympy.core.numbers import equal_valued
8
+ from sympy.core.relational import Relational
9
+ from sympy.core.symbol import Symbol, Dummy
10
+ from sympy.core.sympify import _sympify
11
+ from sympy.functions.elementary.complexes import Abs, im, re
12
+ from sympy.functions.elementary.exponential import exp, log
13
+ from sympy.functions.elementary.integers import frac
14
+ from sympy.functions.elementary.piecewise import Piecewise
15
+ from sympy.functions.elementary.trigonometric import (
16
+ TrigonometricFunction, sin, cos, tan, cot, csc, sec,
17
+ asin, acos, acot, atan, asec, acsc)
18
+ from sympy.functions.elementary.hyperbolic import (sinh, cosh, tanh, coth,
19
+ sech, csch, asinh, acosh, atanh, acoth, asech, acsch)
20
+ from sympy.polys.polytools import degree, lcm_list
21
+ from sympy.sets.sets import (Interval, Intersection, FiniteSet, Union,
22
+ Complement)
23
+ from sympy.sets.fancysets import ImageSet
24
+ from sympy.sets.conditionset import ConditionSet
25
+ from sympy.utilities import filldedent
26
+ from sympy.utilities.iterables import iterable
27
+ from sympy.matrices.dense import hessian
28
+
29
+
30
+ def continuous_domain(f, symbol, domain):
31
+ """
32
+ Returns the domain on which the function expression f is continuous.
33
+
34
+ This function is limited by the ability to determine the various
35
+ singularities and discontinuities of the given function.
36
+ The result is either given as a union of intervals or constructed using
37
+ other set operations.
38
+
39
+ Parameters
40
+ ==========
41
+
42
+ f : :py:class:`~.Expr`
43
+ The concerned function.
44
+ symbol : :py:class:`~.Symbol`
45
+ The variable for which the intervals are to be determined.
46
+ domain : :py:class:`~.Interval`
47
+ The domain over which the continuity of the symbol has to be checked.
48
+
49
+ Examples
50
+ ========
51
+
52
+ >>> from sympy import Interval, Symbol, S, tan, log, pi, sqrt
53
+ >>> from sympy.calculus.util import continuous_domain
54
+ >>> x = Symbol('x')
55
+ >>> continuous_domain(1/x, x, S.Reals)
56
+ Union(Interval.open(-oo, 0), Interval.open(0, oo))
57
+ >>> continuous_domain(tan(x), x, Interval(0, pi))
58
+ Union(Interval.Ropen(0, pi/2), Interval.Lopen(pi/2, pi))
59
+ >>> continuous_domain(sqrt(x - 2), x, Interval(-5, 5))
60
+ Interval(2, 5)
61
+ >>> continuous_domain(log(2*x - 1), x, S.Reals)
62
+ Interval.open(1/2, oo)
63
+
64
+ Returns
65
+ =======
66
+
67
+ :py:class:`~.Interval`
68
+ Union of all intervals where the function is continuous.
69
+
70
+ Raises
71
+ ======
72
+
73
+ NotImplementedError
74
+ If the method to determine continuity of such a function
75
+ has not yet been developed.
76
+
77
+ """
78
+ from sympy.solvers.inequalities import solve_univariate_inequality
79
+
80
+ if not domain.is_subset(S.Reals):
81
+ raise NotImplementedError(filldedent('''
82
+ Domain must be a subset of S.Reals.
83
+ '''))
84
+ implemented = [Pow, exp, log, Abs, frac,
85
+ sin, cos, tan, cot, sec, csc,
86
+ asin, acos, atan, acot, asec, acsc,
87
+ sinh, cosh, tanh, coth, sech, csch,
88
+ asinh, acosh, atanh, acoth, asech, acsch]
89
+ used = [fct.func for fct in f.atoms(Function) if fct.has(symbol)]
90
+ if any(func not in implemented for func in used):
91
+ raise NotImplementedError(filldedent('''
92
+ Unable to determine the domain of the given function.
93
+ '''))
94
+
95
+ x = Symbol('x')
96
+ constraints = {
97
+ log: (x > 0,),
98
+ asin: (x >= -1, x <= 1),
99
+ acos: (x >= -1, x <= 1),
100
+ acosh: (x >= 1,),
101
+ atanh: (x > -1, x < 1),
102
+ asech: (x > 0, x <= 1)
103
+ }
104
+ constraints_union = {
105
+ asec: (x <= -1, x >= 1),
106
+ acsc: (x <= -1, x >= 1),
107
+ acoth: (x < -1, x > 1)
108
+ }
109
+
110
+ cont_domain = domain
111
+ for atom in f.atoms(Pow):
112
+ den = atom.exp.as_numer_denom()[1]
113
+ if atom.exp.is_rational and den.is_odd:
114
+ pass # 0**negative handled by singularities()
115
+ else:
116
+ constraint = solve_univariate_inequality(atom.base >= 0,
117
+ symbol).as_set()
118
+ cont_domain = Intersection(constraint, cont_domain)
119
+
120
+ for atom in f.atoms(Function):
121
+ if atom.func in constraints:
122
+ for c in constraints[atom.func]:
123
+ constraint_relational = c.subs(x, atom.args[0])
124
+ constraint_set = solve_univariate_inequality(
125
+ constraint_relational, symbol).as_set()
126
+ cont_domain = Intersection(constraint_set, cont_domain)
127
+ elif atom.func in constraints_union:
128
+ constraint_set = S.EmptySet
129
+ for c in constraints_union[atom.func]:
130
+ constraint_relational = c.subs(x, atom.args[0])
131
+ constraint_set += solve_univariate_inequality(
132
+ constraint_relational, symbol).as_set()
133
+ cont_domain = Intersection(constraint_set, cont_domain)
134
+ # XXX: the discontinuities below could be factored out in
135
+ # a new "discontinuities()".
136
+ elif atom.func == acot:
137
+ from sympy.solvers.solveset import solveset_real
138
+ # Sympy's acot() has a step discontinuity at 0. Since it's
139
+ # neither an essential singularity nor a pole, singularities()
140
+ # will not report it. But it's still relevant for determining
141
+ # the continuity of the function f.
142
+ cont_domain -= solveset_real(atom.args[0], symbol)
143
+ # Note that the above may introduce spurious discontinuities, e.g.
144
+ # for abs(acot(x)) at 0.
145
+ elif atom.func == frac:
146
+ from sympy.solvers.solveset import solveset_real
147
+ r = function_range(atom.args[0], symbol, domain)
148
+ r = Intersection(r, S.Integers)
149
+ if r.is_finite_set:
150
+ discont = S.EmptySet
151
+ for n in r:
152
+ discont += solveset_real(atom.args[0]-n, symbol)
153
+ else:
154
+ discont = ConditionSet(
155
+ symbol, S.Integers.contains(atom.args[0]), cont_domain)
156
+ cont_domain -= discont
157
+
158
+ return cont_domain - singularities(f, symbol, domain)
159
+
160
+
161
+ def function_range(f, symbol, domain):
162
+ """
163
+ Finds the range of a function in a given domain.
164
+ This method is limited by the ability to determine the singularities and
165
+ determine limits.
166
+
167
+ Parameters
168
+ ==========
169
+
170
+ f : :py:class:`~.Expr`
171
+ The concerned function.
172
+ symbol : :py:class:`~.Symbol`
173
+ The variable for which the range of function is to be determined.
174
+ domain : :py:class:`~.Interval`
175
+ The domain under which the range of the function has to be found.
176
+
177
+ Examples
178
+ ========
179
+
180
+ >>> from sympy import Interval, Symbol, S, exp, log, pi, sqrt, sin, tan
181
+ >>> from sympy.calculus.util import function_range
182
+ >>> x = Symbol('x')
183
+ >>> function_range(sin(x), x, Interval(0, 2*pi))
184
+ Interval(-1, 1)
185
+ >>> function_range(tan(x), x, Interval(-pi/2, pi/2))
186
+ Interval(-oo, oo)
187
+ >>> function_range(1/x, x, S.Reals)
188
+ Union(Interval.open(-oo, 0), Interval.open(0, oo))
189
+ >>> function_range(exp(x), x, S.Reals)
190
+ Interval.open(0, oo)
191
+ >>> function_range(log(x), x, S.Reals)
192
+ Interval(-oo, oo)
193
+ >>> function_range(sqrt(x), x, Interval(-5, 9))
194
+ Interval(0, 3)
195
+
196
+ Returns
197
+ =======
198
+
199
+ :py:class:`~.Interval`
200
+ Union of all ranges for all intervals under domain where function is
201
+ continuous.
202
+
203
+ Raises
204
+ ======
205
+
206
+ NotImplementedError
207
+ If any of the intervals, in the given domain, for which function
208
+ is continuous are not finite or real,
209
+ OR if the critical points of the function on the domain cannot be found.
210
+ """
211
+
212
+ if domain is S.EmptySet:
213
+ return S.EmptySet
214
+
215
+ period = periodicity(f, symbol)
216
+ if period == S.Zero:
217
+ # the expression is constant wrt symbol
218
+ return FiniteSet(f.expand())
219
+
220
+ from sympy.series.limits import limit
221
+ from sympy.solvers.solveset import solveset
222
+
223
+ if period is not None:
224
+ if isinstance(domain, Interval):
225
+ if (domain.inf - domain.sup).is_infinite:
226
+ domain = Interval(0, period)
227
+ elif isinstance(domain, Union):
228
+ for sub_dom in domain.args:
229
+ if isinstance(sub_dom, Interval) and \
230
+ ((sub_dom.inf - sub_dom.sup).is_infinite):
231
+ domain = Interval(0, period)
232
+
233
+ intervals = continuous_domain(f, symbol, domain)
234
+ range_int = S.EmptySet
235
+ if isinstance(intervals,(Interval, FiniteSet)):
236
+ interval_iter = (intervals,)
237
+
238
+ elif isinstance(intervals, Union):
239
+ interval_iter = intervals.args
240
+
241
+ else:
242
+ raise NotImplementedError(filldedent('''
243
+ Unable to find range for the given domain.
244
+ '''))
245
+
246
+ for interval in interval_iter:
247
+ if isinstance(interval, FiniteSet):
248
+ for singleton in interval:
249
+ if singleton in domain:
250
+ range_int += FiniteSet(f.subs(symbol, singleton))
251
+ elif isinstance(interval, Interval):
252
+ vals = S.EmptySet
253
+ critical_points = S.EmptySet
254
+ critical_values = S.EmptySet
255
+ bounds = ((interval.left_open, interval.inf, '+'),
256
+ (interval.right_open, interval.sup, '-'))
257
+
258
+ for is_open, limit_point, direction in bounds:
259
+ if is_open:
260
+ critical_values += FiniteSet(limit(f, symbol, limit_point, direction))
261
+ vals += critical_values
262
+
263
+ else:
264
+ vals += FiniteSet(f.subs(symbol, limit_point))
265
+
266
+ solution = solveset(f.diff(symbol), symbol, interval)
267
+
268
+ if not iterable(solution):
269
+ raise NotImplementedError(
270
+ 'Unable to find critical points for {}'.format(f))
271
+ if isinstance(solution, ImageSet):
272
+ raise NotImplementedError(
273
+ 'Infinite number of critical points for {}'.format(f))
274
+
275
+ critical_points += solution
276
+
277
+ for critical_point in critical_points:
278
+ vals += FiniteSet(f.subs(symbol, critical_point))
279
+
280
+ left_open, right_open = False, False
281
+
282
+ if critical_values is not S.EmptySet:
283
+ if critical_values.inf == vals.inf:
284
+ left_open = True
285
+
286
+ if critical_values.sup == vals.sup:
287
+ right_open = True
288
+
289
+ range_int += Interval(vals.inf, vals.sup, left_open, right_open)
290
+ else:
291
+ raise NotImplementedError(filldedent('''
292
+ Unable to find range for the given domain.
293
+ '''))
294
+
295
+ return range_int
296
+
297
+
298
+ def not_empty_in(finset_intersection, *syms):
299
+ """
300
+ Finds the domain of the functions in ``finset_intersection`` in which the
301
+ ``finite_set`` is not-empty.
302
+
303
+ Parameters
304
+ ==========
305
+
306
+ finset_intersection : Intersection of FiniteSet
307
+ The unevaluated intersection of FiniteSet containing
308
+ real-valued functions with Union of Sets
309
+ syms : Tuple of symbols
310
+ Symbol for which domain is to be found
311
+
312
+ Raises
313
+ ======
314
+
315
+ NotImplementedError
316
+ The algorithms to find the non-emptiness of the given FiniteSet are
317
+ not yet implemented.
318
+ ValueError
319
+ The input is not valid.
320
+ RuntimeError
321
+ It is a bug, please report it to the github issue tracker
322
+ (https://github.com/sympy/sympy/issues).
323
+
324
+ Examples
325
+ ========
326
+
327
+ >>> from sympy import FiniteSet, Interval, not_empty_in, oo
328
+ >>> from sympy.abc import x
329
+ >>> not_empty_in(FiniteSet(x/2).intersect(Interval(0, 1)), x)
330
+ Interval(0, 2)
331
+ >>> not_empty_in(FiniteSet(x, x**2).intersect(Interval(1, 2)), x)
332
+ Union(Interval(1, 2), Interval(-sqrt(2), -1))
333
+ >>> not_empty_in(FiniteSet(x**2/(x + 2)).intersect(Interval(1, oo)), x)
334
+ Union(Interval.Lopen(-2, -1), Interval(2, oo))
335
+ """
336
+
337
+ # TODO: handle piecewise defined functions
338
+ # TODO: handle transcendental functions
339
+ # TODO: handle multivariate functions
340
+ if len(syms) == 0:
341
+ raise ValueError("One or more symbols must be given in syms.")
342
+
343
+ if finset_intersection is S.EmptySet:
344
+ return S.EmptySet
345
+
346
+ if isinstance(finset_intersection, Union):
347
+ elm_in_sets = finset_intersection.args[0]
348
+ return Union(not_empty_in(finset_intersection.args[1], *syms),
349
+ elm_in_sets)
350
+
351
+ if isinstance(finset_intersection, FiniteSet):
352
+ finite_set = finset_intersection
353
+ _sets = S.Reals
354
+ else:
355
+ finite_set = finset_intersection.args[1]
356
+ _sets = finset_intersection.args[0]
357
+
358
+ if not isinstance(finite_set, FiniteSet):
359
+ raise ValueError('A FiniteSet must be given, not %s: %s' %
360
+ (type(finite_set), finite_set))
361
+
362
+ if len(syms) == 1:
363
+ symb = syms[0]
364
+ else:
365
+ raise NotImplementedError('more than one variables %s not handled' %
366
+ (syms,))
367
+
368
+ def elm_domain(expr, intrvl):
369
+ """ Finds the domain of an expression in any given interval """
370
+ from sympy.solvers.solveset import solveset
371
+
372
+ _start = intrvl.start
373
+ _end = intrvl.end
374
+ _singularities = solveset(expr.as_numer_denom()[1], symb,
375
+ domain=S.Reals)
376
+
377
+ if intrvl.right_open:
378
+ if _end is S.Infinity:
379
+ _domain1 = S.Reals
380
+ else:
381
+ _domain1 = solveset(expr < _end, symb, domain=S.Reals)
382
+ else:
383
+ _domain1 = solveset(expr <= _end, symb, domain=S.Reals)
384
+
385
+ if intrvl.left_open:
386
+ if _start is S.NegativeInfinity:
387
+ _domain2 = S.Reals
388
+ else:
389
+ _domain2 = solveset(expr > _start, symb, domain=S.Reals)
390
+ else:
391
+ _domain2 = solveset(expr >= _start, symb, domain=S.Reals)
392
+
393
+ # domain in the interval
394
+ expr_with_sing = Intersection(_domain1, _domain2)
395
+ expr_domain = Complement(expr_with_sing, _singularities)
396
+ return expr_domain
397
+
398
+ if isinstance(_sets, Interval):
399
+ return Union(*[elm_domain(element, _sets) for element in finite_set])
400
+
401
+ if isinstance(_sets, Union):
402
+ _domain = S.EmptySet
403
+ for intrvl in _sets.args:
404
+ _domain_element = Union(*[elm_domain(element, intrvl)
405
+ for element in finite_set])
406
+ _domain = Union(_domain, _domain_element)
407
+ return _domain
408
+
409
+
410
+ def periodicity(f, symbol, check=False):
411
+ """
412
+ Tests the given function for periodicity in the given symbol.
413
+
414
+ Parameters
415
+ ==========
416
+
417
+ f : :py:class:`~.Expr`
418
+ The concerned function.
419
+ symbol : :py:class:`~.Symbol`
420
+ The variable for which the period is to be determined.
421
+ check : bool, optional
422
+ The flag to verify whether the value being returned is a period or not.
423
+
424
+ Returns
425
+ =======
426
+
427
+ period
428
+ The period of the function is returned.
429
+ ``None`` is returned when the function is aperiodic or has a complex period.
430
+ The value of $0$ is returned as the period of a constant function.
431
+
432
+ Raises
433
+ ======
434
+
435
+ NotImplementedError
436
+ The value of the period computed cannot be verified.
437
+
438
+
439
+ Notes
440
+ =====
441
+
442
+ Currently, we do not support functions with a complex period.
443
+ The period of functions having complex periodic values such
444
+ as ``exp``, ``sinh`` is evaluated to ``None``.
445
+
446
+ The value returned might not be the "fundamental" period of the given
447
+ function i.e. it may not be the smallest periodic value of the function.
448
+
449
+ The verification of the period through the ``check`` flag is not reliable
450
+ due to internal simplification of the given expression. Hence, it is set
451
+ to ``False`` by default.
452
+
453
+ Examples
454
+ ========
455
+ >>> from sympy import periodicity, Symbol, sin, cos, tan, exp
456
+ >>> x = Symbol('x')
457
+ >>> f = sin(x) + sin(2*x) + sin(3*x)
458
+ >>> periodicity(f, x)
459
+ 2*pi
460
+ >>> periodicity(sin(x)*cos(x), x)
461
+ pi
462
+ >>> periodicity(exp(tan(2*x) - 1), x)
463
+ pi/2
464
+ >>> periodicity(sin(4*x)**cos(2*x), x)
465
+ pi
466
+ >>> periodicity(exp(x), x)
467
+ """
468
+ if symbol.kind is not NumberKind:
469
+ raise NotImplementedError("Cannot use symbol of kind %s" % symbol.kind)
470
+ temp = Dummy('x', real=True)
471
+ f = f.subs(symbol, temp)
472
+ symbol = temp
473
+
474
+ def _check(orig_f, period):
475
+ '''Return the checked period or raise an error.'''
476
+ new_f = orig_f.subs(symbol, symbol + period)
477
+ if new_f.equals(orig_f):
478
+ return period
479
+ else:
480
+ raise NotImplementedError(filldedent('''
481
+ The period of the given function cannot be verified.
482
+ When `%s` was replaced with `%s + %s` in `%s`, the result
483
+ was `%s` which was not recognized as being the same as
484
+ the original function.
485
+ So either the period was wrong or the two forms were
486
+ not recognized as being equal.
487
+ Set check=False to obtain the value.''' %
488
+ (symbol, symbol, period, orig_f, new_f)))
489
+
490
+ orig_f = f
491
+ period = None
492
+
493
+ if isinstance(f, Relational):
494
+ f = f.lhs - f.rhs
495
+
496
+ f = f.simplify()
497
+
498
+ if symbol not in f.free_symbols:
499
+ return S.Zero
500
+
501
+ if isinstance(f, TrigonometricFunction):
502
+ try:
503
+ period = f.period(symbol)
504
+ except NotImplementedError:
505
+ pass
506
+
507
+ if isinstance(f, Abs):
508
+ arg = f.args[0]
509
+ if isinstance(arg, (sec, csc, cos)):
510
+ # all but tan and cot might have a
511
+ # a period that is half as large
512
+ # so recast as sin
513
+ arg = sin(arg.args[0])
514
+ period = periodicity(arg, symbol)
515
+ if period is not None and isinstance(arg, sin):
516
+ # the argument of Abs was a trigonometric other than
517
+ # cot or tan; test to see if the half-period
518
+ # is valid. Abs(arg) has behaviour equivalent to
519
+ # orig_f, so use that for test:
520
+ orig_f = Abs(arg)
521
+ try:
522
+ return _check(orig_f, period/2)
523
+ except NotImplementedError as err:
524
+ if check:
525
+ raise NotImplementedError(err)
526
+ # else let new orig_f and period be
527
+ # checked below
528
+
529
+ if isinstance(f, exp) or (f.is_Pow and f.base == S.Exp1):
530
+ f = Pow(S.Exp1, expand_mul(f.exp))
531
+ if im(f) != 0:
532
+ period_real = periodicity(re(f), symbol)
533
+ period_imag = periodicity(im(f), symbol)
534
+ if period_real is not None and period_imag is not None:
535
+ period = lcim([period_real, period_imag])
536
+
537
+ if f.is_Pow and f.base != S.Exp1:
538
+ base, expo = f.args
539
+ base_has_sym = base.has(symbol)
540
+ expo_has_sym = expo.has(symbol)
541
+
542
+ if base_has_sym and not expo_has_sym:
543
+ period = periodicity(base, symbol)
544
+
545
+ elif expo_has_sym and not base_has_sym:
546
+ period = periodicity(expo, symbol)
547
+
548
+ else:
549
+ period = _periodicity(f.args, symbol)
550
+
551
+ elif f.is_Mul:
552
+ coeff, g = f.as_independent(symbol, as_Add=False)
553
+ if isinstance(g, TrigonometricFunction) or not equal_valued(coeff, 1):
554
+ period = periodicity(g, symbol)
555
+ else:
556
+ period = _periodicity(g.args, symbol)
557
+
558
+ elif f.is_Add:
559
+ k, g = f.as_independent(symbol)
560
+ if k is not S.Zero:
561
+ return periodicity(g, symbol)
562
+
563
+ period = _periodicity(g.args, symbol)
564
+
565
+ elif isinstance(f, Mod):
566
+ a, n = f.args
567
+
568
+ if a == symbol:
569
+ period = n
570
+ elif isinstance(a, TrigonometricFunction):
571
+ period = periodicity(a, symbol)
572
+ #check if 'f' is linear in 'symbol'
573
+ elif (a.is_polynomial(symbol) and degree(a, symbol) == 1 and
574
+ symbol not in n.free_symbols):
575
+ period = Abs(n / a.diff(symbol))
576
+
577
+ elif isinstance(f, Piecewise):
578
+ pass # not handling Piecewise yet as the return type is not favorable
579
+
580
+ elif period is None:
581
+ from sympy.solvers.decompogen import compogen, decompogen
582
+ g_s = decompogen(f, symbol)
583
+ num_of_gs = len(g_s)
584
+ if num_of_gs > 1:
585
+ for index, g in enumerate(reversed(g_s)):
586
+ start_index = num_of_gs - 1 - index
587
+ g = compogen(g_s[start_index:], symbol)
588
+ if g not in (orig_f, f): # Fix for issue 12620
589
+ period = periodicity(g, symbol)
590
+ if period is not None:
591
+ break
592
+
593
+ if period is not None:
594
+ if check:
595
+ return _check(orig_f, period)
596
+ return period
597
+
598
+ return None
599
+
600
+
601
+ def _periodicity(args, symbol):
602
+ """
603
+ Helper for `periodicity` to find the period of a list of simpler
604
+ functions.
605
+ It uses the `lcim` method to find the least common period of
606
+ all the functions.
607
+
608
+ Parameters
609
+ ==========
610
+
611
+ args : Tuple of :py:class:`~.Symbol`
612
+ All the symbols present in a function.
613
+
614
+ symbol : :py:class:`~.Symbol`
615
+ The symbol over which the function is to be evaluated.
616
+
617
+ Returns
618
+ =======
619
+
620
+ period
621
+ The least common period of the function for all the symbols
622
+ of the function.
623
+ ``None`` if for at least one of the symbols the function is aperiodic.
624
+
625
+ """
626
+ periods = []
627
+ for f in args:
628
+ period = periodicity(f, symbol)
629
+ if period is None:
630
+ return None
631
+
632
+ if period is not S.Zero:
633
+ periods.append(period)
634
+
635
+ if len(periods) > 1:
636
+ return lcim(periods)
637
+
638
+ if periods:
639
+ return periods[0]
640
+
641
+
642
+ def lcim(numbers):
643
+ """Returns the least common integral multiple of a list of numbers.
644
+
645
+ The numbers can be rational or irrational or a mixture of both.
646
+ `None` is returned for incommensurable numbers.
647
+
648
+ Parameters
649
+ ==========
650
+
651
+ numbers : list
652
+ Numbers (rational and/or irrational) for which lcim is to be found.
653
+
654
+ Returns
655
+ =======
656
+
657
+ number
658
+ lcim if it exists, otherwise ``None`` for incommensurable numbers.
659
+
660
+ Examples
661
+ ========
662
+
663
+ >>> from sympy.calculus.util import lcim
664
+ >>> from sympy import S, pi
665
+ >>> lcim([S(1)/2, S(3)/4, S(5)/6])
666
+ 15/2
667
+ >>> lcim([2*pi, 3*pi, pi, pi/2])
668
+ 6*pi
669
+ >>> lcim([S(1), 2*pi])
670
+ """
671
+ result = None
672
+ if all(num.is_irrational for num in numbers):
673
+ factorized_nums = [num.factor() for num in numbers]
674
+ factors_num = [num.as_coeff_Mul() for num in factorized_nums]
675
+ term = factors_num[0][1]
676
+ if all(factor == term for coeff, factor in factors_num):
677
+ common_term = term
678
+ coeffs = [coeff for coeff, factor in factors_num]
679
+ result = lcm_list(coeffs) * common_term
680
+
681
+ elif all(num.is_rational for num in numbers):
682
+ result = lcm_list(numbers)
683
+
684
+ else:
685
+ pass
686
+
687
+ return result
688
+
689
+ def is_convex(f, *syms, domain=S.Reals):
690
+ r"""Determines the convexity of the function passed in the argument.
691
+
692
+ Parameters
693
+ ==========
694
+
695
+ f : :py:class:`~.Expr`
696
+ The concerned function.
697
+ syms : Tuple of :py:class:`~.Symbol`
698
+ The variables with respect to which the convexity is to be determined.
699
+ domain : :py:class:`~.Interval`, optional
700
+ The domain over which the convexity of the function has to be checked.
701
+ If unspecified, S.Reals will be the default domain.
702
+
703
+ Returns
704
+ =======
705
+
706
+ bool
707
+ The method returns ``True`` if the function is convex otherwise it
708
+ returns ``False``.
709
+
710
+ Raises
711
+ ======
712
+
713
+ NotImplementedError
714
+ The check for the convexity of multivariate functions is not implemented yet.
715
+
716
+ Notes
717
+ =====
718
+
719
+ To determine concavity of a function pass `-f` as the concerned function.
720
+ To determine logarithmic convexity of a function pass `\log(f)` as
721
+ concerned function.
722
+ To determine logarithmic concavity of a function pass `-\log(f)` as
723
+ concerned function.
724
+
725
+ Currently, convexity check of multivariate functions is not handled.
726
+
727
+ Examples
728
+ ========
729
+
730
+ >>> from sympy import is_convex, symbols, exp, oo, Interval
731
+ >>> x = symbols('x')
732
+ >>> is_convex(exp(x), x)
733
+ True
734
+ >>> is_convex(x**3, x, domain = Interval(-1, oo))
735
+ False
736
+ >>> is_convex(1/x**2, x, domain=Interval.open(0, oo))
737
+ True
738
+
739
+ References
740
+ ==========
741
+
742
+ .. [1] https://en.wikipedia.org/wiki/Convex_function
743
+ .. [2] http://www.ifp.illinois.edu/~angelia/L3_convfunc.pdf
744
+ .. [3] https://en.wikipedia.org/wiki/Logarithmically_convex_function
745
+ .. [4] https://en.wikipedia.org/wiki/Logarithmically_concave_function
746
+ .. [5] https://en.wikipedia.org/wiki/Concave_function
747
+
748
+ """
749
+ if len(syms) > 1 :
750
+ return hessian(f, syms).is_positive_semidefinite
751
+ from sympy.solvers.inequalities import solve_univariate_inequality
752
+ f = _sympify(f)
753
+ var = syms[0]
754
+ if any(s in domain for s in singularities(f, var)):
755
+ return False
756
+ condition = f.diff(var, 2) < 0
757
+ if solve_univariate_inequality(condition, var, False, domain):
758
+ return False
759
+ return True
760
+
761
+
762
+ def stationary_points(f, symbol, domain=S.Reals):
763
+ """
764
+ Returns the stationary points of a function (where derivative of the
765
+ function is 0) in the given domain.
766
+
767
+ Parameters
768
+ ==========
769
+
770
+ f : :py:class:`~.Expr`
771
+ The concerned function.
772
+ symbol : :py:class:`~.Symbol`
773
+ The variable for which the stationary points are to be determined.
774
+ domain : :py:class:`~.Interval`
775
+ The domain over which the stationary points have to be checked.
776
+ If unspecified, ``S.Reals`` will be the default domain.
777
+
778
+ Returns
779
+ =======
780
+
781
+ Set
782
+ A set of stationary points for the function. If there are no
783
+ stationary point, an :py:class:`~.EmptySet` is returned.
784
+
785
+ Examples
786
+ ========
787
+
788
+ >>> from sympy import Interval, Symbol, S, sin, pi, pprint, stationary_points
789
+ >>> x = Symbol('x')
790
+
791
+ >>> stationary_points(1/x, x, S.Reals)
792
+ EmptySet
793
+
794
+ >>> pprint(stationary_points(sin(x), x), use_unicode=False)
795
+ pi 3*pi
796
+ {2*n*pi + -- | n in Integers} U {2*n*pi + ---- | n in Integers}
797
+ 2 2
798
+
799
+ >>> stationary_points(sin(x),x, Interval(0, 4*pi))
800
+ {pi/2, 3*pi/2, 5*pi/2, 7*pi/2}
801
+
802
+ """
803
+ from sympy.solvers.solveset import solveset
804
+
805
+ if domain is S.EmptySet:
806
+ return S.EmptySet
807
+
808
+ domain = continuous_domain(f, symbol, domain)
809
+ set = solveset(diff(f, symbol), symbol, domain)
810
+
811
+ return set
812
+
813
+
814
+ def maximum(f, symbol, domain=S.Reals):
815
+ """
816
+ Returns the maximum value of a function in the given domain.
817
+
818
+ Parameters
819
+ ==========
820
+
821
+ f : :py:class:`~.Expr`
822
+ The concerned function.
823
+ symbol : :py:class:`~.Symbol`
824
+ The variable for maximum value needs to be determined.
825
+ domain : :py:class:`~.Interval`
826
+ The domain over which the maximum have to be checked.
827
+ If unspecified, then the global maximum is returned.
828
+
829
+ Returns
830
+ =======
831
+
832
+ number
833
+ Maximum value of the function in given domain.
834
+
835
+ Examples
836
+ ========
837
+
838
+ >>> from sympy import Interval, Symbol, S, sin, cos, pi, maximum
839
+ >>> x = Symbol('x')
840
+
841
+ >>> f = -x**2 + 2*x + 5
842
+ >>> maximum(f, x, S.Reals)
843
+ 6
844
+
845
+ >>> maximum(sin(x), x, Interval(-pi, pi/4))
846
+ sqrt(2)/2
847
+
848
+ >>> maximum(sin(x)*cos(x), x)
849
+ 1/2
850
+
851
+ """
852
+ if isinstance(symbol, Symbol):
853
+ if domain is S.EmptySet:
854
+ raise ValueError("Maximum value not defined for empty domain.")
855
+
856
+ return function_range(f, symbol, domain).sup
857
+ else:
858
+ raise ValueError("%s is not a valid symbol." % symbol)
859
+
860
+
861
+ def minimum(f, symbol, domain=S.Reals):
862
+ """
863
+ Returns the minimum value of a function in the given domain.
864
+
865
+ Parameters
866
+ ==========
867
+
868
+ f : :py:class:`~.Expr`
869
+ The concerned function.
870
+ symbol : :py:class:`~.Symbol`
871
+ The variable for minimum value needs to be determined.
872
+ domain : :py:class:`~.Interval`
873
+ The domain over which the minimum have to be checked.
874
+ If unspecified, then the global minimum is returned.
875
+
876
+ Returns
877
+ =======
878
+
879
+ number
880
+ Minimum value of the function in the given domain.
881
+
882
+ Examples
883
+ ========
884
+
885
+ >>> from sympy import Interval, Symbol, S, sin, cos, minimum
886
+ >>> x = Symbol('x')
887
+
888
+ >>> f = x**2 + 2*x + 5
889
+ >>> minimum(f, x, S.Reals)
890
+ 4
891
+
892
+ >>> minimum(sin(x), x, Interval(2, 3))
893
+ sin(3)
894
+
895
+ >>> minimum(sin(x)*cos(x), x)
896
+ -1/2
897
+
898
+ """
899
+ if isinstance(symbol, Symbol):
900
+ if domain is S.EmptySet:
901
+ raise ValueError("Minimum value not defined for empty domain.")
902
+
903
+ return function_range(f, symbol, domain).inf
904
+ else:
905
+ raise ValueError("%s is not a valid symbol." % symbol)
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+ size 114999
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+ version https://git-lfs.github.com/spec/v1
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+ size 101044
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/__init__.py ADDED
@@ -0,0 +1,67 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ Number theory module (primes, etc)
3
+ """
4
+
5
+ from .generate import nextprime, prevprime, prime, primepi, primerange, \
6
+ randprime, Sieve, sieve, primorial, cycle_length, composite, compositepi
7
+ from .primetest import isprime, is_gaussian_prime, is_mersenne_prime
8
+ from .factor_ import divisors, proper_divisors, factorint, multiplicity, \
9
+ multiplicity_in_factorial, perfect_power, pollard_pm1, pollard_rho, \
10
+ primefactors, totient, \
11
+ divisor_count, proper_divisor_count, divisor_sigma, factorrat, \
12
+ reduced_totient, primenu, primeomega, mersenne_prime_exponent, \
13
+ is_perfect, is_abundant, is_deficient, is_amicable, is_carmichael, \
14
+ abundance, dra, drm
15
+
16
+ from .partitions_ import npartitions
17
+ from .residue_ntheory import is_primitive_root, is_quad_residue, \
18
+ legendre_symbol, jacobi_symbol, n_order, sqrt_mod, quadratic_residues, \
19
+ primitive_root, nthroot_mod, is_nthpow_residue, sqrt_mod_iter, mobius, \
20
+ discrete_log, quadratic_congruence, polynomial_congruence
21
+ from .multinomial import binomial_coefficients, binomial_coefficients_list, \
22
+ multinomial_coefficients
23
+ from .continued_fraction import continued_fraction_periodic, \
24
+ continued_fraction_iterator, continued_fraction_reduce, \
25
+ continued_fraction_convergents, continued_fraction
26
+ from .digits import count_digits, digits, is_palindromic
27
+ from .egyptian_fraction import egyptian_fraction
28
+ from .ecm import ecm
29
+ from .qs import qs
30
+ __all__ = [
31
+ 'nextprime', 'prevprime', 'prime', 'primepi', 'primerange', 'randprime',
32
+ 'Sieve', 'sieve', 'primorial', 'cycle_length', 'composite', 'compositepi',
33
+
34
+ 'isprime', 'is_gaussian_prime', 'is_mersenne_prime',
35
+
36
+
37
+ 'divisors', 'proper_divisors', 'factorint', 'multiplicity', 'perfect_power',
38
+ 'pollard_pm1', 'pollard_rho', 'primefactors', 'totient',
39
+ 'divisor_count', 'proper_divisor_count', 'divisor_sigma', 'factorrat',
40
+ 'reduced_totient', 'primenu', 'primeomega', 'mersenne_prime_exponent',
41
+ 'is_perfect', 'is_abundant', 'is_deficient', 'is_amicable',
42
+ 'is_carmichael', 'abundance', 'dra', 'drm', 'multiplicity_in_factorial',
43
+
44
+ 'npartitions',
45
+
46
+ 'is_primitive_root', 'is_quad_residue', 'legendre_symbol',
47
+ 'jacobi_symbol', 'n_order', 'sqrt_mod', 'quadratic_residues',
48
+ 'primitive_root', 'nthroot_mod', 'is_nthpow_residue', 'sqrt_mod_iter',
49
+ 'mobius', 'discrete_log', 'quadratic_congruence', 'polynomial_congruence',
50
+
51
+ 'binomial_coefficients', 'binomial_coefficients_list',
52
+ 'multinomial_coefficients',
53
+
54
+ 'continued_fraction_periodic', 'continued_fraction_iterator',
55
+ 'continued_fraction_reduce', 'continued_fraction_convergents',
56
+ 'continued_fraction',
57
+
58
+ 'digits',
59
+ 'count_digits',
60
+ 'is_palindromic',
61
+
62
+ 'egyptian_fraction',
63
+
64
+ 'ecm',
65
+
66
+ 'qs',
67
+ ]
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infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/bbp_pi.py ADDED
@@ -0,0 +1,190 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ '''
2
+ This implementation is a heavily modified fixed point implementation of
3
+ BBP_formula for calculating the nth position of pi. The original hosted
4
+ at: https://web.archive.org/web/20151116045029/http://en.literateprograms.org/Pi_with_the_BBP_formula_(Python)
5
+
6
+ # Permission is hereby granted, free of charge, to any person obtaining
7
+ # a copy of this software and associated documentation files (the
8
+ # "Software"), to deal in the Software without restriction, including
9
+ # without limitation the rights to use, copy, modify, merge, publish,
10
+ # distribute, sub-license, and/or sell copies of the Software, and to
11
+ # permit persons to whom the Software is furnished to do so, subject to
12
+ # the following conditions:
13
+ #
14
+ # The above copyright notice and this permission notice shall be
15
+ # included in all copies or substantial portions of the Software.
16
+ #
17
+ # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18
+ # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19
+ # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20
+ # IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
21
+ # CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22
+ # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23
+ # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24
+
25
+ Modifications:
26
+
27
+ 1.Once the nth digit and desired number of digits is selected, the
28
+ number of digits of working precision is calculated to ensure that
29
+ the hexadecimal digits returned are accurate. This is calculated as
30
+
31
+ int(math.log(start + prec)/math.log(16) + prec + 3)
32
+ --------------------------------------- --------
33
+ / /
34
+ number of hex digits additional digits
35
+
36
+ This was checked by the following code which completed without
37
+ errors (and dig are the digits included in the test_bbp.py file):
38
+
39
+ for i in range(0,1000):
40
+ for j in range(1,1000):
41
+ a, b = pi_hex_digits(i, j), dig[i:i+j]
42
+ if a != b:
43
+ print('%s\n%s'%(a,b))
44
+
45
+ Deceasing the additional digits by 1 generated errors, so '3' is
46
+ the smallest additional precision needed to calculate the above
47
+ loop without errors. The following trailing 10 digits were also
48
+ checked to be accurate (and the times were slightly faster with
49
+ some of the constant modifications that were made):
50
+
51
+ >> from time import time
52
+ >> t=time();pi_hex_digits(10**2-10 + 1, 10), time()-t
53
+ ('e90c6cc0ac', 0.0)
54
+ >> t=time();pi_hex_digits(10**4-10 + 1, 10), time()-t
55
+ ('26aab49ec6', 0.17100000381469727)
56
+ >> t=time();pi_hex_digits(10**5-10 + 1, 10), time()-t
57
+ ('a22673c1a5', 4.7109999656677246)
58
+ >> t=time();pi_hex_digits(10**6-10 + 1, 10), time()-t
59
+ ('9ffd342362', 59.985999822616577)
60
+ >> t=time();pi_hex_digits(10**7-10 + 1, 10), time()-t
61
+ ('c1a42e06a1', 689.51800012588501)
62
+
63
+ 2. The while loop to evaluate whether the series has converged quits
64
+ when the addition amount `dt` has dropped to zero.
65
+
66
+ 3. the formatting string to convert the decimal to hexadecimal is
67
+ calculated for the given precision.
68
+
69
+ 4. pi_hex_digits(n) changed to have coefficient to the formula in an
70
+ array (perhaps just a matter of preference).
71
+
72
+ '''
73
+
74
+ from sympy.utilities.misc import as_int
75
+
76
+
77
+ def _series(j, n, prec=14):
78
+
79
+ # Left sum from the bbp algorithm
80
+ s = 0
81
+ D = _dn(n, prec)
82
+ D4 = 4 * D
83
+ d = j
84
+ for k in range(n + 1):
85
+ s += (pow(16, n - k, d) << D4) // d
86
+ d += 8
87
+
88
+ # Right sum iterates to infinity for full precision, but we
89
+ # stop at the point where one iteration is beyond the precision
90
+ # specified.
91
+
92
+ t = 0
93
+ k = n + 1
94
+ e = D4 - 4 # 4*(D + n - k)
95
+ d = 8 * k + j
96
+ while True:
97
+ dt = (1 << e) // d
98
+ if not dt:
99
+ break
100
+ t += dt
101
+ # k += 1
102
+ e -= 4
103
+ d += 8
104
+ total = s + t
105
+
106
+ return total
107
+
108
+
109
+ def pi_hex_digits(n, prec=14):
110
+ """Returns a string containing ``prec`` (default 14) digits
111
+ starting at the nth digit of pi in hex. Counting of digits
112
+ starts at 0 and the decimal is not counted, so for n = 0 the
113
+ returned value starts with 3; n = 1 corresponds to the first
114
+ digit past the decimal point (which in hex is 2).
115
+
116
+ Parameters
117
+ ==========
118
+
119
+ n : non-negative integer
120
+ prec : non-negative integer. default = 14
121
+
122
+ Returns
123
+ =======
124
+
125
+ str : Returns a string containing ``prec`` digits
126
+ starting at the nth digit of pi in hex.
127
+ If ``prec`` = 0, returns empty string.
128
+
129
+ Raises
130
+ ======
131
+
132
+ ValueError
133
+ If ``n`` < 0 or ``prec`` < 0.
134
+ Or ``n`` or ``prec`` is not an integer.
135
+
136
+ Examples
137
+ ========
138
+
139
+ >>> from sympy.ntheory.bbp_pi import pi_hex_digits
140
+ >>> pi_hex_digits(0)
141
+ '3243f6a8885a30'
142
+ >>> pi_hex_digits(0, 3)
143
+ '324'
144
+
145
+ These are consistent with the following results
146
+
147
+ >>> import math
148
+ >>> hex(int(math.pi * 2**((14-1)*4)))
149
+ '0x3243f6a8885a30'
150
+ >>> hex(int(math.pi * 2**((3-1)*4)))
151
+ '0x324'
152
+
153
+ References
154
+ ==========
155
+
156
+ .. [1] http://www.numberworld.org/digits/Pi/
157
+ """
158
+ n, prec = as_int(n), as_int(prec)
159
+ if n < 0:
160
+ raise ValueError('n cannot be negative')
161
+ if prec < 0:
162
+ raise ValueError('prec cannot be negative')
163
+ if prec == 0:
164
+ return ''
165
+
166
+ # main of implementation arrays holding formulae coefficients
167
+ n -= 1
168
+ a = [4, 2, 1, 1]
169
+ j = [1, 4, 5, 6]
170
+
171
+ #formulae
172
+ D = _dn(n, prec)
173
+ x = + (a[0]*_series(j[0], n, prec)
174
+ - a[1]*_series(j[1], n, prec)
175
+ - a[2]*_series(j[2], n, prec)
176
+ - a[3]*_series(j[3], n, prec)) & (16**D - 1)
177
+
178
+ s = ("%0" + "%ix" % prec) % (x // 16**(D - prec))
179
+ return s
180
+
181
+
182
+ def _dn(n, prec):
183
+ # controller for n dependence on precision
184
+ # n = starting digit index
185
+ # prec = the number of total digits to compute
186
+ n += 1 # because we subtract 1 for _series
187
+
188
+ # assert int(math.log(n + prec)/math.log(16)) ==\
189
+ # ((n + prec).bit_length() - 1) // 4
190
+ return ((n + prec).bit_length() - 1) // 4 + prec + 3
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/continued_fraction.py ADDED
@@ -0,0 +1,369 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from __future__ import annotations
2
+ import itertools
3
+ from sympy.core.exprtools import factor_terms
4
+ from sympy.core.numbers import Integer, Rational
5
+ from sympy.core.singleton import S
6
+ from sympy.core.symbol import Dummy
7
+ from sympy.core.sympify import _sympify
8
+ from sympy.utilities.misc import as_int
9
+
10
+
11
+ def continued_fraction(a) -> list:
12
+ """Return the continued fraction representation of a Rational or
13
+ quadratic irrational.
14
+
15
+ Examples
16
+ ========
17
+
18
+ >>> from sympy.ntheory.continued_fraction import continued_fraction
19
+ >>> from sympy import sqrt
20
+ >>> continued_fraction((1 + 2*sqrt(3))/5)
21
+ [0, 1, [8, 3, 34, 3]]
22
+
23
+ See Also
24
+ ========
25
+ continued_fraction_periodic, continued_fraction_reduce, continued_fraction_convergents
26
+ """
27
+ e = _sympify(a)
28
+ if all(i.is_Rational for i in e.atoms()):
29
+ if e.is_Integer:
30
+ return continued_fraction_periodic(e, 1, 0)
31
+ elif e.is_Rational:
32
+ return continued_fraction_periodic(e.p, e.q, 0)
33
+ elif e.is_Pow and e.exp is S.Half and e.base.is_Integer:
34
+ return continued_fraction_periodic(0, 1, e.base)
35
+ elif e.is_Mul and len(e.args) == 2 and (
36
+ e.args[0].is_Rational and
37
+ e.args[1].is_Pow and
38
+ e.args[1].base.is_Integer and
39
+ e.args[1].exp is S.Half):
40
+ a, b = e.args
41
+ return continued_fraction_periodic(0, a.q, b.base, a.p)
42
+ else:
43
+ # this should not have to work very hard- no
44
+ # simplification, cancel, etc... which should be
45
+ # done by the user. e.g. This is a fancy 1 but
46
+ # the user should simplify it first:
47
+ # sqrt(2)*(1 + sqrt(2))/(sqrt(2) + 2)
48
+ p, d = e.expand().as_numer_denom()
49
+ if d.is_Integer:
50
+ if p.is_Rational:
51
+ return continued_fraction_periodic(p, d)
52
+ # look for a + b*c
53
+ # with c = sqrt(s)
54
+ if p.is_Add and len(p.args) == 2:
55
+ a, bc = p.args
56
+ else:
57
+ a = S.Zero
58
+ bc = p
59
+ if a.is_Integer:
60
+ b = S.NaN
61
+ if bc.is_Mul and len(bc.args) == 2:
62
+ b, c = bc.args
63
+ elif bc.is_Pow:
64
+ b = Integer(1)
65
+ c = bc
66
+ if b.is_Integer and (
67
+ c.is_Pow and c.exp is S.Half and
68
+ c.base.is_Integer):
69
+ # (a + b*sqrt(c))/d
70
+ c = c.base
71
+ return continued_fraction_periodic(a, d, c, b)
72
+ raise ValueError(
73
+ 'expecting a rational or quadratic irrational, not %s' % e)
74
+
75
+
76
+ def continued_fraction_periodic(p, q, d=0, s=1) -> list:
77
+ r"""
78
+ Find the periodic continued fraction expansion of a quadratic irrational.
79
+
80
+ Compute the continued fraction expansion of a rational or a
81
+ quadratic irrational number, i.e. `\frac{p + s\sqrt{d}}{q}`, where
82
+ `p`, `q \ne 0` and `d \ge 0` are integers.
83
+
84
+ Returns the continued fraction representation (canonical form) as
85
+ a list of integers, optionally ending (for quadratic irrationals)
86
+ with list of integers representing the repeating digits.
87
+
88
+ Parameters
89
+ ==========
90
+
91
+ p : int
92
+ the rational part of the number's numerator
93
+ q : int
94
+ the denominator of the number
95
+ d : int, optional
96
+ the irrational part (discriminator) of the number's numerator
97
+ s : int, optional
98
+ the coefficient of the irrational part
99
+
100
+ Examples
101
+ ========
102
+
103
+ >>> from sympy.ntheory.continued_fraction import continued_fraction_periodic
104
+ >>> continued_fraction_periodic(3, 2, 7)
105
+ [2, [1, 4, 1, 1]]
106
+
107
+ Golden ratio has the simplest continued fraction expansion:
108
+
109
+ >>> continued_fraction_periodic(1, 2, 5)
110
+ [[1]]
111
+
112
+ If the discriminator is zero or a perfect square then the number will be a
113
+ rational number:
114
+
115
+ >>> continued_fraction_periodic(4, 3, 0)
116
+ [1, 3]
117
+ >>> continued_fraction_periodic(4, 3, 49)
118
+ [3, 1, 2]
119
+
120
+ See Also
121
+ ========
122
+
123
+ continued_fraction_iterator, continued_fraction_reduce
124
+
125
+ References
126
+ ==========
127
+
128
+ .. [1] https://en.wikipedia.org/wiki/Periodic_continued_fraction
129
+ .. [2] K. Rosen. Elementary Number theory and its applications.
130
+ Addison-Wesley, 3 Sub edition, pages 379-381, January 1992.
131
+
132
+ """
133
+ from sympy.functions import sqrt, floor
134
+
135
+ p, q, d, s = list(map(as_int, [p, q, d, s]))
136
+
137
+ if d < 0:
138
+ raise ValueError("expected non-negative for `d` but got %s" % d)
139
+
140
+ if q == 0:
141
+ raise ValueError("The denominator cannot be 0.")
142
+
143
+ if not s:
144
+ d = 0
145
+
146
+ # check for rational case
147
+ sd = sqrt(d)
148
+ if sd.is_Integer:
149
+ return list(continued_fraction_iterator(Rational(p + s*sd, q)))
150
+
151
+ # irrational case with sd != Integer
152
+ if q < 0:
153
+ p, q, s = -p, -q, -s
154
+
155
+ n = (p + s*sd)/q
156
+ if n < 0:
157
+ w = floor(-n)
158
+ f = -n - w
159
+ one_f = continued_fraction(1 - f) # 1-f < 1 so cf is [0 ... [...]]
160
+ one_f[0] -= w + 1
161
+ return one_f
162
+
163
+ d *= s**2
164
+ sd *= s
165
+
166
+ if (d - p**2)%q:
167
+ d *= q**2
168
+ sd *= q
169
+ p *= q
170
+ q *= q
171
+
172
+ terms: list[int] = []
173
+ pq = {}
174
+
175
+ while (p, q) not in pq:
176
+ pq[(p, q)] = len(terms)
177
+ terms.append((p + sd)//q)
178
+ p = terms[-1]*q - p
179
+ q = (d - p**2)//q
180
+
181
+ i = pq[(p, q)]
182
+ return terms[:i] + [terms[i:]] # type: ignore
183
+
184
+
185
+ def continued_fraction_reduce(cf):
186
+ """
187
+ Reduce a continued fraction to a rational or quadratic irrational.
188
+
189
+ Compute the rational or quadratic irrational number from its
190
+ terminating or periodic continued fraction expansion. The
191
+ continued fraction expansion (cf) should be supplied as a
192
+ terminating iterator supplying the terms of the expansion. For
193
+ terminating continued fractions, this is equivalent to
194
+ ``list(continued_fraction_convergents(cf))[-1]``, only a little more
195
+ efficient. If the expansion has a repeating part, a list of the
196
+ repeating terms should be returned as the last element from the
197
+ iterator. This is the format returned by
198
+ continued_fraction_periodic.
199
+
200
+ For quadratic irrationals, returns the largest solution found,
201
+ which is generally the one sought, if the fraction is in canonical
202
+ form (all terms positive except possibly the first).
203
+
204
+ Examples
205
+ ========
206
+
207
+ >>> from sympy.ntheory.continued_fraction import continued_fraction_reduce
208
+ >>> continued_fraction_reduce([1, 2, 3, 4, 5])
209
+ 225/157
210
+ >>> continued_fraction_reduce([-2, 1, 9, 7, 1, 2])
211
+ -256/233
212
+ >>> continued_fraction_reduce([2, 1, 2, 1, 1, 4, 1, 1, 6, 1, 1, 8]).n(10)
213
+ 2.718281835
214
+ >>> continued_fraction_reduce([1, 4, 2, [3, 1]])
215
+ (sqrt(21) + 287)/238
216
+ >>> continued_fraction_reduce([[1]])
217
+ (1 + sqrt(5))/2
218
+ >>> from sympy.ntheory.continued_fraction import continued_fraction_periodic
219
+ >>> continued_fraction_reduce(continued_fraction_periodic(8, 5, 13))
220
+ (sqrt(13) + 8)/5
221
+
222
+ See Also
223
+ ========
224
+
225
+ continued_fraction_periodic
226
+
227
+ """
228
+ from sympy.solvers import solve
229
+
230
+ period = []
231
+ x = Dummy('x')
232
+
233
+ def untillist(cf):
234
+ for nxt in cf:
235
+ if isinstance(nxt, list):
236
+ period.extend(nxt)
237
+ yield x
238
+ break
239
+ yield nxt
240
+
241
+ a = S.Zero
242
+ for a in continued_fraction_convergents(untillist(cf)):
243
+ pass
244
+
245
+ if period:
246
+ y = Dummy('y')
247
+ solns = solve(continued_fraction_reduce(period + [y]) - y, y)
248
+ solns.sort()
249
+ pure = solns[-1]
250
+ rv = a.subs(x, pure).radsimp()
251
+ else:
252
+ rv = a
253
+ if rv.is_Add:
254
+ rv = factor_terms(rv)
255
+ if rv.is_Mul and rv.args[0] == -1:
256
+ rv = rv.func(*rv.args)
257
+ return rv
258
+
259
+
260
+ def continued_fraction_iterator(x):
261
+ """
262
+ Return continued fraction expansion of x as iterator.
263
+
264
+ Examples
265
+ ========
266
+
267
+ >>> from sympy import Rational, pi
268
+ >>> from sympy.ntheory.continued_fraction import continued_fraction_iterator
269
+
270
+ >>> list(continued_fraction_iterator(Rational(3, 8)))
271
+ [0, 2, 1, 2]
272
+ >>> list(continued_fraction_iterator(Rational(-3, 8)))
273
+ [-1, 1, 1, 1, 2]
274
+
275
+ >>> for i, v in enumerate(continued_fraction_iterator(pi)):
276
+ ... if i > 7:
277
+ ... break
278
+ ... print(v)
279
+ 3
280
+ 7
281
+ 15
282
+ 1
283
+ 292
284
+ 1
285
+ 1
286
+ 1
287
+
288
+ References
289
+ ==========
290
+
291
+ .. [1] https://en.wikipedia.org/wiki/Continued_fraction
292
+
293
+ """
294
+ from sympy.functions import floor
295
+ while True:
296
+ i = floor(x)
297
+ yield i
298
+ x -= i
299
+ if not x:
300
+ break
301
+ x = 1/x
302
+
303
+
304
+ def continued_fraction_convergents(cf):
305
+ """
306
+ Return an iterator over the convergents of a continued fraction (cf).
307
+
308
+ The parameter should be in either of the following to forms:
309
+ - A list of partial quotients, possibly with the last element being a list
310
+ of repeating partial quotients, such as might be returned by
311
+ continued_fraction and continued_fraction_periodic.
312
+ - An iterable returning successive partial quotients of the continued
313
+ fraction, such as might be returned by continued_fraction_iterator.
314
+
315
+ In computing the convergents, the continued fraction need not be strictly
316
+ in canonical form (all integers, all but the first positive).
317
+ Rational and negative elements may be present in the expansion.
318
+
319
+ Examples
320
+ ========
321
+
322
+ >>> from sympy.core import pi
323
+ >>> from sympy import S
324
+ >>> from sympy.ntheory.continued_fraction import \
325
+ continued_fraction_convergents, continued_fraction_iterator
326
+
327
+ >>> list(continued_fraction_convergents([0, 2, 1, 2]))
328
+ [0, 1/2, 1/3, 3/8]
329
+
330
+ >>> list(continued_fraction_convergents([1, S('1/2'), -7, S('1/4')]))
331
+ [1, 3, 19/5, 7]
332
+
333
+ >>> it = continued_fraction_convergents(continued_fraction_iterator(pi))
334
+ >>> for n in range(7):
335
+ ... print(next(it))
336
+ 3
337
+ 22/7
338
+ 333/106
339
+ 355/113
340
+ 103993/33102
341
+ 104348/33215
342
+ 208341/66317
343
+
344
+ >>> it = continued_fraction_convergents([1, [1, 2]]) # sqrt(3)
345
+ >>> for n in range(7):
346
+ ... print(next(it))
347
+ 1
348
+ 2
349
+ 5/3
350
+ 7/4
351
+ 19/11
352
+ 26/15
353
+ 71/41
354
+
355
+ See Also
356
+ ========
357
+
358
+ continued_fraction_iterator, continued_fraction, continued_fraction_periodic
359
+
360
+ """
361
+ if isinstance(cf, list) and isinstance(cf[-1], list):
362
+ cf = itertools.chain(cf[:-1], itertools.cycle(cf[-1]))
363
+ p_2, q_2 = S.Zero, S.One
364
+ p_1, q_1 = S.One, S.Zero
365
+ for a in cf:
366
+ p, q = a*p_1 + p_2, a*q_1 + q_2
367
+ p_2, q_2 = p_1, q_1
368
+ p_1, q_1 = p, q
369
+ yield p/q
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/egyptian_fraction.py ADDED
@@ -0,0 +1,223 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.containers import Tuple
2
+ from sympy.core.numbers import (Integer, Rational)
3
+ from sympy.core.singleton import S
4
+ import sympy.polys
5
+
6
+ from math import gcd
7
+
8
+
9
+ def egyptian_fraction(r, algorithm="Greedy"):
10
+ """
11
+ Return the list of denominators of an Egyptian fraction
12
+ expansion [1]_ of the said rational `r`.
13
+
14
+ Parameters
15
+ ==========
16
+
17
+ r : Rational or (p, q)
18
+ a positive rational number, ``p/q``.
19
+ algorithm : { "Greedy", "Graham Jewett", "Takenouchi", "Golomb" }, optional
20
+ Denotes the algorithm to be used (the default is "Greedy").
21
+
22
+ Examples
23
+ ========
24
+
25
+ >>> from sympy import Rational
26
+ >>> from sympy.ntheory.egyptian_fraction import egyptian_fraction
27
+ >>> egyptian_fraction(Rational(3, 7))
28
+ [3, 11, 231]
29
+ >>> egyptian_fraction((3, 7), "Graham Jewett")
30
+ [7, 8, 9, 56, 57, 72, 3192]
31
+ >>> egyptian_fraction((3, 7), "Takenouchi")
32
+ [4, 7, 28]
33
+ >>> egyptian_fraction((3, 7), "Golomb")
34
+ [3, 15, 35]
35
+ >>> egyptian_fraction((11, 5), "Golomb")
36
+ [1, 2, 3, 4, 9, 234, 1118, 2580]
37
+
38
+ See Also
39
+ ========
40
+
41
+ sympy.core.numbers.Rational
42
+
43
+ Notes
44
+ =====
45
+
46
+ Currently the following algorithms are supported:
47
+
48
+ 1) Greedy Algorithm
49
+
50
+ Also called the Fibonacci-Sylvester algorithm [2]_.
51
+ At each step, extract the largest unit fraction less
52
+ than the target and replace the target with the remainder.
53
+
54
+ It has some distinct properties:
55
+
56
+ a) Given `p/q` in lowest terms, generates an expansion of maximum
57
+ length `p`. Even as the numerators get large, the number of
58
+ terms is seldom more than a handful.
59
+
60
+ b) Uses minimal memory.
61
+
62
+ c) The terms can blow up (standard examples of this are 5/121 and
63
+ 31/311). The denominator is at most squared at each step
64
+ (doubly-exponential growth) and typically exhibits
65
+ singly-exponential growth.
66
+
67
+ 2) Graham Jewett Algorithm
68
+
69
+ The algorithm suggested by the result of Graham and Jewett.
70
+ Note that this has a tendency to blow up: the length of the
71
+ resulting expansion is always ``2**(x/gcd(x, y)) - 1``. See [3]_.
72
+
73
+ 3) Takenouchi Algorithm
74
+
75
+ The algorithm suggested by Takenouchi (1921).
76
+ Differs from the Graham-Jewett algorithm only in the handling
77
+ of duplicates. See [3]_.
78
+
79
+ 4) Golomb's Algorithm
80
+
81
+ A method given by Golumb (1962), using modular arithmetic and
82
+ inverses. It yields the same results as a method using continued
83
+ fractions proposed by Bleicher (1972). See [4]_.
84
+
85
+ If the given rational is greater than or equal to 1, a greedy algorithm
86
+ of summing the harmonic sequence 1/1 + 1/2 + 1/3 + ... is used, taking
87
+ all the unit fractions of this sequence until adding one more would be
88
+ greater than the given number. This list of denominators is prefixed
89
+ to the result from the requested algorithm used on the remainder. For
90
+ example, if r is 8/3, using the Greedy algorithm, we get [1, 2, 3, 4,
91
+ 5, 6, 7, 14, 420], where the beginning of the sequence, [1, 2, 3, 4, 5,
92
+ 6, 7] is part of the harmonic sequence summing to 363/140, leaving a
93
+ remainder of 31/420, which yields [14, 420] by the Greedy algorithm.
94
+ The result of egyptian_fraction(Rational(8, 3), "Golomb") is [1, 2, 3,
95
+ 4, 5, 6, 7, 14, 574, 2788, 6460, 11590, 33062, 113820], and so on.
96
+
97
+ References
98
+ ==========
99
+
100
+ .. [1] https://en.wikipedia.org/wiki/Egyptian_fraction
101
+ .. [2] https://en.wikipedia.org/wiki/Greedy_algorithm_for_Egyptian_fractions
102
+ .. [3] https://www.ics.uci.edu/~eppstein/numth/egypt/conflict.html
103
+ .. [4] https://web.archive.org/web/20180413004012/https://ami.ektf.hu/uploads/papers/finalpdf/AMI_42_from129to134.pdf
104
+
105
+ """
106
+
107
+ if not isinstance(r, Rational):
108
+ if isinstance(r, (Tuple, tuple)) and len(r) == 2:
109
+ r = Rational(*r)
110
+ else:
111
+ raise ValueError("Value must be a Rational or tuple of ints")
112
+ if r <= 0:
113
+ raise ValueError("Value must be positive")
114
+
115
+ # common cases that all methods agree on
116
+ x, y = r.as_numer_denom()
117
+ if y == 1 and x == 2:
118
+ return [Integer(i) for i in [1, 2, 3, 6]]
119
+ if x == y + 1:
120
+ return [S.One, y]
121
+
122
+ prefix, rem = egypt_harmonic(r)
123
+ if rem == 0:
124
+ return prefix
125
+ # work in Python ints
126
+ x, y = rem.p, rem.q
127
+ # assert x < y and gcd(x, y) = 1
128
+
129
+ if algorithm == "Greedy":
130
+ postfix = egypt_greedy(x, y)
131
+ elif algorithm == "Graham Jewett":
132
+ postfix = egypt_graham_jewett(x, y)
133
+ elif algorithm == "Takenouchi":
134
+ postfix = egypt_takenouchi(x, y)
135
+ elif algorithm == "Golomb":
136
+ postfix = egypt_golomb(x, y)
137
+ else:
138
+ raise ValueError("Entered invalid algorithm")
139
+ return prefix + [Integer(i) for i in postfix]
140
+
141
+
142
+ def egypt_greedy(x, y):
143
+ # assumes gcd(x, y) == 1
144
+ if x == 1:
145
+ return [y]
146
+ else:
147
+ a = (-y) % x
148
+ b = y*(y//x + 1)
149
+ c = gcd(a, b)
150
+ if c > 1:
151
+ num, denom = a//c, b//c
152
+ else:
153
+ num, denom = a, b
154
+ return [y//x + 1] + egypt_greedy(num, denom)
155
+
156
+
157
+ def egypt_graham_jewett(x, y):
158
+ # assumes gcd(x, y) == 1
159
+ l = [y] * x
160
+
161
+ # l is now a list of integers whose reciprocals sum to x/y.
162
+ # we shall now proceed to manipulate the elements of l without
163
+ # changing the reciprocated sum until all elements are unique.
164
+
165
+ while len(l) != len(set(l)):
166
+ l.sort() # so the list has duplicates. find a smallest pair
167
+ for i in range(len(l) - 1):
168
+ if l[i] == l[i + 1]:
169
+ break
170
+ # we have now identified a pair of identical
171
+ # elements: l[i] and l[i + 1].
172
+ # now comes the application of the result of graham and jewett:
173
+ l[i + 1] = l[i] + 1
174
+ # and we just iterate that until the list has no duplicates.
175
+ l.append(l[i]*(l[i] + 1))
176
+ return sorted(l)
177
+
178
+
179
+ def egypt_takenouchi(x, y):
180
+ # assumes gcd(x, y) == 1
181
+ # special cases for 3/y
182
+ if x == 3:
183
+ if y % 2 == 0:
184
+ return [y//2, y]
185
+ i = (y - 1)//2
186
+ j = i + 1
187
+ k = j + i
188
+ return [j, k, j*k]
189
+ l = [y] * x
190
+ while len(l) != len(set(l)):
191
+ l.sort()
192
+ for i in range(len(l) - 1):
193
+ if l[i] == l[i + 1]:
194
+ break
195
+ k = l[i]
196
+ if k % 2 == 0:
197
+ l[i] = l[i] // 2
198
+ del l[i + 1]
199
+ else:
200
+ l[i], l[i + 1] = (k + 1)//2, k*(k + 1)//2
201
+ return sorted(l)
202
+
203
+
204
+ def egypt_golomb(x, y):
205
+ # assumes x < y and gcd(x, y) == 1
206
+ if x == 1:
207
+ return [y]
208
+ xp = sympy.polys.ZZ.invert(int(x), int(y))
209
+ rv = [xp*y]
210
+ rv.extend(egypt_golomb((x*xp - 1)//y, xp))
211
+ return sorted(rv)
212
+
213
+
214
+ def egypt_harmonic(r):
215
+ # assumes r is Rational
216
+ rv = []
217
+ d = S.One
218
+ acc = S.Zero
219
+ while acc + 1/d <= r:
220
+ acc += 1/d
221
+ rv.append(d)
222
+ d += 1
223
+ return (rv, r - acc)
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/elliptic_curve.py ADDED
@@ -0,0 +1,397 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.core.numbers import oo
2
+ from sympy.core.symbol import symbols
3
+ from sympy.polys.domains import FiniteField, QQ, RationalField, FF
4
+ from sympy.polys.polytools import Poly
5
+ from sympy.solvers.solvers import solve
6
+ from sympy.utilities.iterables import is_sequence
7
+ from sympy.utilities.misc import as_int
8
+ from .factor_ import divisors
9
+ from .residue_ntheory import polynomial_congruence
10
+
11
+
12
+ class EllipticCurve:
13
+ """
14
+ Create the following Elliptic Curve over domain.
15
+
16
+ `y^{2} + a_{1} x y + a_{3} y = x^{3} + a_{2} x^{2} + a_{4} x + a_{6}`
17
+
18
+ The default domain is ``QQ``. If no coefficient ``a1``, ``a2``, ``a3``,
19
+ is given then it creates a curve with the following form:
20
+
21
+ `y^{2} = x^{3} + a_{4} x + a_{6}`
22
+
23
+ Examples
24
+ ========
25
+
26
+ References
27
+ ==========
28
+
29
+ .. [1] J. Silverman "A Friendly Introduction to Number Theory" Third Edition
30
+ .. [2] https://mathworld.wolfram.com/EllipticDiscriminant.html
31
+ .. [3] G. Hardy, E. Wright "An Introduction to the Theory of Numbers" Sixth Edition
32
+
33
+ """
34
+
35
+ def __init__(self, a4, a6, a1=0, a2=0, a3=0, modulus=0):
36
+ if modulus == 0:
37
+ domain = QQ
38
+ else:
39
+ domain = FF(modulus)
40
+ a1, a2, a3, a4, a6 = map(domain.convert, (a1, a2, a3, a4, a6))
41
+ self._domain = domain
42
+ self.modulus = modulus
43
+ # Calculate discriminant
44
+ b2 = a1**2 + 4 * a2
45
+ b4 = 2 * a4 + a1 * a3
46
+ b6 = a3**2 + 4 * a6
47
+ b8 = a1**2 * a6 + 4 * a2 * a6 - a1 * a3 * a4 + a2 * a3**2 - a4**2
48
+ self._b2, self._b4, self._b6, self._b8 = b2, b4, b6, b8
49
+ self._discrim = -b2**2 * b8 - 8 * b4**3 - 27 * b6**2 + 9 * b2 * b4 * b6
50
+ self._a1 = a1
51
+ self._a2 = a2
52
+ self._a3 = a3
53
+ self._a4 = a4
54
+ self._a6 = a6
55
+ x, y, z = symbols('x y z')
56
+ self.x, self.y, self.z = x, y, z
57
+ self._poly = Poly(y**2*z + a1*x*y*z + a3*y*z**2 - x**3 - a2*x**2*z - a4*x*z**2 - a6*z**3, domain=domain)
58
+ if isinstance(self._domain, FiniteField):
59
+ self._rank = 0
60
+ elif isinstance(self._domain, RationalField):
61
+ self._rank = None
62
+
63
+ def __call__(self, x, y, z=1):
64
+ return EllipticCurvePoint(x, y, z, self)
65
+
66
+ def __contains__(self, point):
67
+ if is_sequence(point):
68
+ if len(point) == 2:
69
+ z1 = 1
70
+ else:
71
+ z1 = point[2]
72
+ x1, y1 = point[:2]
73
+ elif isinstance(point, EllipticCurvePoint):
74
+ x1, y1, z1 = point.x, point.y, point.z
75
+ else:
76
+ raise ValueError('Invalid point.')
77
+ if self.characteristic == 0 and z1 == 0:
78
+ return True
79
+ return self._poly.subs({self.x: x1, self.y: y1, self.z: z1}) == 0
80
+
81
+ def __repr__(self):
82
+ return self._poly.__repr__()
83
+
84
+ def minimal(self):
85
+ """
86
+ Return minimal Weierstrass equation.
87
+
88
+ Examples
89
+ ========
90
+
91
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
92
+
93
+ >>> e1 = EllipticCurve(-10, -20, 0, -1, 1)
94
+ >>> e1.minimal()
95
+ Poly(-x**3 + 13392*x*z**2 + y**2*z + 1080432*z**3, x, y, z, domain='QQ')
96
+
97
+ """
98
+ char = self.characteristic
99
+ if char == 2:
100
+ return self
101
+ if char == 3:
102
+ return EllipticCurve(self._b4/2, self._b6/4, a2=self._b2/4, modulus=self.modulus)
103
+ c4 = self._b2**2 - 24*self._b4
104
+ c6 = -self._b2**3 + 36*self._b2*self._b4 - 216*self._b6
105
+ return EllipticCurve(-27*c4, -54*c6, modulus=self.modulus)
106
+
107
+ def points(self):
108
+ """
109
+ Return points of curve over Finite Field.
110
+
111
+ Examples
112
+ ========
113
+
114
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
115
+ >>> e2 = EllipticCurve(1, 1, 1, 1, 1, modulus=5)
116
+ >>> e2.points()
117
+ {(0, 2), (1, 4), (2, 0), (2, 2), (3, 0), (3, 1), (4, 0)}
118
+
119
+ """
120
+
121
+ char = self.characteristic
122
+ all_pt = set()
123
+ if char >= 1:
124
+ for i in range(char):
125
+ congruence_eq = self._poly.subs({self.x: i, self.z: 1}).expr
126
+ sol = polynomial_congruence(congruence_eq, char)
127
+ all_pt.update((i, num) for num in sol)
128
+ return all_pt
129
+ else:
130
+ raise ValueError("Infinitely many points")
131
+
132
+ def points_x(self, x):
133
+ """Returns points on the curve for the given x-coordinate."""
134
+ pt = []
135
+ if self._domain == QQ:
136
+ for y in solve(self._poly.subs(self.x, x)):
137
+ pt.append((x, y))
138
+ else:
139
+ congruence_eq = self._poly.subs({self.x: x, self.z: 1}).expr
140
+ for y in polynomial_congruence(congruence_eq, self.characteristic):
141
+ pt.append((x, y))
142
+ return pt
143
+
144
+ def torsion_points(self):
145
+ """
146
+ Return torsion points of curve over Rational number.
147
+
148
+ Return point objects those are finite order.
149
+ According to Nagell-Lutz theorem, torsion point p(x, y)
150
+ x and y are integers, either y = 0 or y**2 is divisor
151
+ of discriminent. According to Mazur's theorem, there are
152
+ at most 15 points in torsion collection.
153
+
154
+ Examples
155
+ ========
156
+
157
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
158
+ >>> e2 = EllipticCurve(-43, 166)
159
+ >>> sorted(e2.torsion_points())
160
+ [(-5, -16), (-5, 16), O, (3, -8), (3, 8), (11, -32), (11, 32)]
161
+
162
+ """
163
+ if self.characteristic > 0:
164
+ raise ValueError("No torsion point for Finite Field.")
165
+ l = [EllipticCurvePoint.point_at_infinity(self)]
166
+ for xx in solve(self._poly.subs({self.y: 0, self.z: 1})):
167
+ if xx.is_rational:
168
+ l.append(self(xx, 0))
169
+ for i in divisors(self.discriminant, generator=True):
170
+ j = int(i**.5)
171
+ if j**2 == i:
172
+ for xx in solve(self._poly.subs({self.y: j, self.z: 1})):
173
+ if not xx.is_rational:
174
+ continue
175
+ p = self(xx, j)
176
+ if p.order() != oo:
177
+ l.extend([p, -p])
178
+ return l
179
+
180
+ @property
181
+ def characteristic(self):
182
+ """
183
+ Return domain characteristic.
184
+
185
+ Examples
186
+ ========
187
+
188
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
189
+ >>> e2 = EllipticCurve(-43, 166)
190
+ >>> e2.characteristic
191
+ 0
192
+
193
+ """
194
+ return self._domain.characteristic()
195
+
196
+ @property
197
+ def discriminant(self):
198
+ """
199
+ Return curve discriminant.
200
+
201
+ Examples
202
+ ========
203
+
204
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
205
+ >>> e2 = EllipticCurve(0, 17)
206
+ >>> e2.discriminant
207
+ -124848
208
+
209
+ """
210
+ return int(self._discrim)
211
+
212
+ @property
213
+ def is_singular(self):
214
+ """
215
+ Return True if curve discriminant is equal to zero.
216
+ """
217
+ return self.discriminant == 0
218
+
219
+ @property
220
+ def j_invariant(self):
221
+ """
222
+ Return curve j-invariant.
223
+
224
+ Examples
225
+ ========
226
+
227
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
228
+ >>> e1 = EllipticCurve(-2, 0, 0, 1, 1)
229
+ >>> e1.j_invariant
230
+ 1404928/389
231
+
232
+ """
233
+ c4 = self._b2**2 - 24*self._b4
234
+ return self._domain.to_sympy(c4**3 / self._discrim)
235
+
236
+ @property
237
+ def order(self):
238
+ """
239
+ Number of points in Finite field.
240
+
241
+ Examples
242
+ ========
243
+
244
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
245
+ >>> e2 = EllipticCurve(1, 0, modulus=19)
246
+ >>> e2.order
247
+ 19
248
+
249
+ """
250
+ if self.characteristic == 0:
251
+ raise NotImplementedError("Still not implemented")
252
+ return len(self.points())
253
+
254
+ @property
255
+ def rank(self):
256
+ """
257
+ Number of independent points of infinite order.
258
+
259
+ For Finite field, it must be 0.
260
+ """
261
+ if self._rank is not None:
262
+ return self._rank
263
+ raise NotImplementedError("Still not implemented")
264
+
265
+
266
+ class EllipticCurvePoint:
267
+ """
268
+ Point of Elliptic Curve
269
+
270
+ Examples
271
+ ========
272
+
273
+ >>> from sympy.ntheory.elliptic_curve import EllipticCurve
274
+ >>> e1 = EllipticCurve(-17, 16)
275
+ >>> p1 = e1(0, -4, 1)
276
+ >>> p2 = e1(1, 0)
277
+ >>> p1 + p2
278
+ (15, -56)
279
+ >>> e3 = EllipticCurve(-1, 9)
280
+ >>> e3(1, -3) * 3
281
+ (664/169, 17811/2197)
282
+ >>> (e3(1, -3) * 3).order()
283
+ oo
284
+ >>> e2 = EllipticCurve(-2, 0, 0, 1, 1)
285
+ >>> p = e2(-1,1)
286
+ >>> q = e2(0, -1)
287
+ >>> p+q
288
+ (4, 8)
289
+ >>> p-q
290
+ (1, 0)
291
+ >>> 3*p-5*q
292
+ (328/361, -2800/6859)
293
+ """
294
+
295
+ @staticmethod
296
+ def point_at_infinity(curve):
297
+ return EllipticCurvePoint(0, 1, 0, curve)
298
+
299
+ def __init__(self, x, y, z, curve):
300
+ dom = curve._domain.convert
301
+ self.x = dom(x)
302
+ self.y = dom(y)
303
+ self.z = dom(z)
304
+ self._curve = curve
305
+ self._domain = self._curve._domain
306
+ if not self._curve.__contains__(self):
307
+ raise ValueError("The curve does not contain this point")
308
+
309
+ def __add__(self, p):
310
+ if self.z == 0:
311
+ return p
312
+ if p.z == 0:
313
+ return self
314
+ x1, y1 = self.x/self.z, self.y/self.z
315
+ x2, y2 = p.x/p.z, p.y/p.z
316
+ a1 = self._curve._a1
317
+ a2 = self._curve._a2
318
+ a3 = self._curve._a3
319
+ a4 = self._curve._a4
320
+ a6 = self._curve._a6
321
+ if x1 != x2:
322
+ slope = (y1 - y2) / (x1 - x2)
323
+ yint = (y1 * x2 - y2 * x1) / (x2 - x1)
324
+ else:
325
+ if (y1 + y2) == 0:
326
+ return self.point_at_infinity(self._curve)
327
+ slope = (3 * x1**2 + 2*a2*x1 + a4 - a1*y1) / (a1 * x1 + a3 + 2 * y1)
328
+ yint = (-x1**3 + a4*x1 + 2*a6 - a3*y1) / (a1*x1 + a3 + 2*y1)
329
+ x3 = slope**2 + a1*slope - a2 - x1 - x2
330
+ y3 = -(slope + a1) * x3 - yint - a3
331
+ return self._curve(x3, y3, 1)
332
+
333
+ def __lt__(self, other):
334
+ return (self.x, self.y, self.z) < (other.x, other.y, other.z)
335
+
336
+ def __mul__(self, n):
337
+ n = as_int(n)
338
+ r = self.point_at_infinity(self._curve)
339
+ if n == 0:
340
+ return r
341
+ if n < 0:
342
+ return -self * -n
343
+ p = self
344
+ while n:
345
+ if n & 1:
346
+ r = r + p
347
+ n >>= 1
348
+ p = p + p
349
+ return r
350
+
351
+ def __rmul__(self, n):
352
+ return self * n
353
+
354
+ def __neg__(self):
355
+ return EllipticCurvePoint(self.x, -self.y - self._curve._a1*self.x - self._curve._a3, self.z, self._curve)
356
+
357
+ def __repr__(self):
358
+ if self.z == 0:
359
+ return 'O'
360
+ dom = self._curve._domain
361
+ try:
362
+ return '({}, {})'.format(dom.to_sympy(self.x), dom.to_sympy(self.y))
363
+ except TypeError:
364
+ pass
365
+ return '({}, {})'.format(self.x, self.y)
366
+
367
+ def __sub__(self, other):
368
+ return self.__add__(-other)
369
+
370
+ def order(self):
371
+ """
372
+ Return point order n where nP = 0.
373
+
374
+ """
375
+ if self.z == 0:
376
+ return 1
377
+ if self.y == 0: # P = -P
378
+ return 2
379
+ p = self * 2
380
+ if p.y == -self.y: # 2P = -P
381
+ return 3
382
+ i = 2
383
+ if self._domain != QQ:
384
+ while int(p.x) == p.x and int(p.y) == p.y:
385
+ p = self + p
386
+ i += 1
387
+ if p.z == 0:
388
+ return i
389
+ return oo
390
+ while p.x.numerator == p.x and p.y.numerator == p.y:
391
+ p = self + p
392
+ i += 1
393
+ if i > 12:
394
+ return oo
395
+ if p.z == 0:
396
+ return i
397
+ return oo
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/factor_.py ADDED
@@ -0,0 +1,2668 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ """
2
+ Integer factorization
3
+ """
4
+
5
+ from collections import defaultdict
6
+ import math
7
+
8
+ from sympy.core.containers import Dict
9
+ from sympy.core.mul import Mul
10
+ from sympy.core.numbers import Rational, Integer
11
+ from sympy.core.intfunc import num_digits
12
+ from sympy.core.power import Pow
13
+ from sympy.core.random import _randint
14
+ from sympy.core.singleton import S
15
+ from sympy.external.gmpy import (SYMPY_INTS, gcd, sqrt as isqrt,
16
+ sqrtrem, iroot, bit_scan1, remove)
17
+ from .primetest import isprime, MERSENNE_PRIME_EXPONENTS, is_mersenne_prime
18
+ from .generate import sieve, primerange, nextprime
19
+ from .digits import digits
20
+ from sympy.utilities.decorator import deprecated
21
+ from sympy.utilities.iterables import flatten
22
+ from sympy.utilities.misc import as_int, filldedent
23
+ from .ecm import _ecm_one_factor
24
+
25
+
26
+ def smoothness(n):
27
+ """
28
+ Return the B-smooth and B-power smooth values of n.
29
+
30
+ The smoothness of n is the largest prime factor of n; the power-
31
+ smoothness is the largest divisor raised to its multiplicity.
32
+
33
+ Examples
34
+ ========
35
+
36
+ >>> from sympy.ntheory.factor_ import smoothness
37
+ >>> smoothness(2**7*3**2)
38
+ (3, 128)
39
+ >>> smoothness(2**4*13)
40
+ (13, 16)
41
+ >>> smoothness(2)
42
+ (2, 2)
43
+
44
+ See Also
45
+ ========
46
+
47
+ factorint, smoothness_p
48
+ """
49
+
50
+ if n == 1:
51
+ return (1, 1) # not prime, but otherwise this causes headaches
52
+ facs = factorint(n)
53
+ return max(facs), max(m**facs[m] for m in facs)
54
+
55
+
56
+ def smoothness_p(n, m=-1, power=0, visual=None):
57
+ """
58
+ Return a list of [m, (p, (M, sm(p + m), psm(p + m)))...]
59
+ where:
60
+
61
+ 1. p**M is the base-p divisor of n
62
+ 2. sm(p + m) is the smoothness of p + m (m = -1 by default)
63
+ 3. psm(p + m) is the power smoothness of p + m
64
+
65
+ The list is sorted according to smoothness (default) or by power smoothness
66
+ if power=1.
67
+
68
+ The smoothness of the numbers to the left (m = -1) or right (m = 1) of a
69
+ factor govern the results that are obtained from the p +/- 1 type factoring
70
+ methods.
71
+
72
+ >>> from sympy.ntheory.factor_ import smoothness_p, factorint
73
+ >>> smoothness_p(10431, m=1)
74
+ (1, [(3, (2, 2, 4)), (19, (1, 5, 5)), (61, (1, 31, 31))])
75
+ >>> smoothness_p(10431)
76
+ (-1, [(3, (2, 2, 2)), (19, (1, 3, 9)), (61, (1, 5, 5))])
77
+ >>> smoothness_p(10431, power=1)
78
+ (-1, [(3, (2, 2, 2)), (61, (1, 5, 5)), (19, (1, 3, 9))])
79
+
80
+ If visual=True then an annotated string will be returned:
81
+
82
+ >>> print(smoothness_p(21477639576571, visual=1))
83
+ p**i=4410317**1 has p-1 B=1787, B-pow=1787
84
+ p**i=4869863**1 has p-1 B=2434931, B-pow=2434931
85
+
86
+ This string can also be generated directly from a factorization dictionary
87
+ and vice versa:
88
+
89
+ >>> factorint(17*9)
90
+ {3: 2, 17: 1}
91
+ >>> smoothness_p(_)
92
+ 'p**i=3**2 has p-1 B=2, B-pow=2\\np**i=17**1 has p-1 B=2, B-pow=16'
93
+ >>> smoothness_p(_)
94
+ {3: 2, 17: 1}
95
+
96
+ The table of the output logic is:
97
+
98
+ ====== ====== ======= =======
99
+ | Visual
100
+ ------ ----------------------
101
+ Input True False other
102
+ ====== ====== ======= =======
103
+ dict str tuple str
104
+ str str tuple dict
105
+ tuple str tuple str
106
+ n str tuple tuple
107
+ mul str tuple tuple
108
+ ====== ====== ======= =======
109
+
110
+ See Also
111
+ ========
112
+
113
+ factorint, smoothness
114
+ """
115
+
116
+ # visual must be True, False or other (stored as None)
117
+ if visual in (1, 0):
118
+ visual = bool(visual)
119
+ elif visual not in (True, False):
120
+ visual = None
121
+
122
+ if isinstance(n, str):
123
+ if visual:
124
+ return n
125
+ d = {}
126
+ for li in n.splitlines():
127
+ k, v = [int(i) for i in
128
+ li.split('has')[0].split('=')[1].split('**')]
129
+ d[k] = v
130
+ if visual is not True and visual is not False:
131
+ return d
132
+ return smoothness_p(d, visual=False)
133
+ elif not isinstance(n, tuple):
134
+ facs = factorint(n, visual=False)
135
+
136
+ if power:
137
+ k = -1
138
+ else:
139
+ k = 1
140
+ if isinstance(n, tuple):
141
+ rv = n
142
+ else:
143
+ rv = (m, sorted([(f,
144
+ tuple([M] + list(smoothness(f + m))))
145
+ for f, M in list(facs.items())],
146
+ key=lambda x: (x[1][k], x[0])))
147
+
148
+ if visual is False or (visual is not True) and (type(n) in [int, Mul]):
149
+ return rv
150
+ lines = []
151
+ for dat in rv[1]:
152
+ dat = flatten(dat)
153
+ dat.insert(2, m)
154
+ lines.append('p**i=%i**%i has p%+i B=%i, B-pow=%i' % tuple(dat))
155
+ return '\n'.join(lines)
156
+
157
+
158
+ def multiplicity(p, n):
159
+ """
160
+ Find the greatest integer m such that p**m divides n.
161
+
162
+ Examples
163
+ ========
164
+
165
+ >>> from sympy import multiplicity, Rational
166
+ >>> [multiplicity(5, n) for n in [8, 5, 25, 125, 250]]
167
+ [0, 1, 2, 3, 3]
168
+ >>> multiplicity(3, Rational(1, 9))
169
+ -2
170
+
171
+ Note: when checking for the multiplicity of a number in a
172
+ large factorial it is most efficient to send it as an unevaluated
173
+ factorial or to call ``multiplicity_in_factorial`` directly:
174
+
175
+ >>> from sympy.ntheory import multiplicity_in_factorial
176
+ >>> from sympy import factorial
177
+ >>> p = factorial(25)
178
+ >>> n = 2**100
179
+ >>> nfac = factorial(n, evaluate=False)
180
+ >>> multiplicity(p, nfac)
181
+ 52818775009509558395695966887
182
+ >>> _ == multiplicity_in_factorial(p, n)
183
+ True
184
+
185
+ See Also
186
+ ========
187
+
188
+ trailing
189
+
190
+ """
191
+ try:
192
+ p, n = as_int(p), as_int(n)
193
+ except ValueError:
194
+ from sympy.functions.combinatorial.factorials import factorial
195
+ if all(isinstance(i, (SYMPY_INTS, Rational)) for i in (p, n)):
196
+ p = Rational(p)
197
+ n = Rational(n)
198
+ if p.q == 1:
199
+ if n.p == 1:
200
+ return -multiplicity(p.p, n.q)
201
+ return multiplicity(p.p, n.p) - multiplicity(p.p, n.q)
202
+ elif p.p == 1:
203
+ return multiplicity(p.q, n.q)
204
+ else:
205
+ like = min(
206
+ multiplicity(p.p, n.p),
207
+ multiplicity(p.q, n.q))
208
+ cross = min(
209
+ multiplicity(p.q, n.p),
210
+ multiplicity(p.p, n.q))
211
+ return like - cross
212
+ elif (isinstance(p, (SYMPY_INTS, Integer)) and
213
+ isinstance(n, factorial) and
214
+ isinstance(n.args[0], Integer) and
215
+ n.args[0] >= 0):
216
+ return multiplicity_in_factorial(p, n.args[0])
217
+ raise ValueError('expecting ints or fractions, got %s and %s' % (p, n))
218
+
219
+ if n == 0:
220
+ raise ValueError('no such integer exists: multiplicity of %s is not-defined' %(n))
221
+ return remove(n, p)[1]
222
+
223
+
224
+ def multiplicity_in_factorial(p, n):
225
+ """return the largest integer ``m`` such that ``p**m`` divides ``n!``
226
+ without calculating the factorial of ``n``.
227
+
228
+ Parameters
229
+ ==========
230
+
231
+ p : Integer
232
+ positive integer
233
+ n : Integer
234
+ non-negative integer
235
+
236
+ Examples
237
+ ========
238
+
239
+ >>> from sympy.ntheory import multiplicity_in_factorial
240
+ >>> from sympy import factorial
241
+
242
+ >>> multiplicity_in_factorial(2, 3)
243
+ 1
244
+
245
+ An instructive use of this is to tell how many trailing zeros
246
+ a given factorial has. For example, there are 6 in 25!:
247
+
248
+ >>> factorial(25)
249
+ 15511210043330985984000000
250
+ >>> multiplicity_in_factorial(10, 25)
251
+ 6
252
+
253
+ For large factorials, it is much faster/feasible to use
254
+ this function rather than computing the actual factorial:
255
+
256
+ >>> multiplicity_in_factorial(factorial(25), 2**100)
257
+ 52818775009509558395695966887
258
+
259
+ See Also
260
+ ========
261
+
262
+ multiplicity
263
+
264
+ """
265
+
266
+ p, n = as_int(p), as_int(n)
267
+
268
+ if p <= 0:
269
+ raise ValueError('expecting positive integer got %s' % p )
270
+
271
+ if n < 0:
272
+ raise ValueError('expecting non-negative integer got %s' % n )
273
+
274
+ # keep only the largest of a given multiplicity since those
275
+ # of a given multiplicity will be goverened by the behavior
276
+ # of the largest factor
277
+ f = defaultdict(int)
278
+ for k, v in factorint(p).items():
279
+ f[v] = max(k, f[v])
280
+ # multiplicity of p in n! depends on multiplicity
281
+ # of prime `k` in p, so we floor divide by `v`
282
+ # and keep it if smaller than the multiplicity of p
283
+ # seen so far
284
+ return min((n + k - sum(digits(n, k)))//(k - 1)//v for v, k in f.items())
285
+
286
+
287
+ def _perfect_power(n, next_p=2):
288
+ """ Return integers ``(b, e)`` such that ``n == b**e`` if ``n`` is a unique
289
+ perfect power with ``e > 1``, else ``False`` (e.g. 1 is not a perfect power).
290
+
291
+ Explanation
292
+ ===========
293
+
294
+ This is a low-level helper for ``perfect_power``, for internal use.
295
+
296
+ Parameters
297
+ ==========
298
+
299
+ n : int
300
+ assume that n is a nonnegative integer
301
+ next_p : int
302
+ Assume that n has no factor less than next_p.
303
+ i.e., all(n % p for p in range(2, next_p)) is True
304
+
305
+ Examples
306
+ ========
307
+ >>> from sympy.ntheory.factor_ import _perfect_power
308
+ >>> _perfect_power(16)
309
+ (2, 4)
310
+ >>> _perfect_power(17)
311
+ False
312
+
313
+ """
314
+ if n <= 3:
315
+ return False
316
+
317
+ factors = {}
318
+ g = 0
319
+ multi = 1
320
+
321
+ def done(n, factors, g, multi):
322
+ g = gcd(g, multi)
323
+ if g == 1:
324
+ return False
325
+ factors[n] = multi
326
+ return math.prod(p**(e//g) for p, e in factors.items()), g
327
+
328
+ # If n is small, only trial factoring is faster
329
+ if n <= 1_000_000:
330
+ n = _factorint_small(factors, n, 1_000, 1_000, next_p)[0]
331
+ if n > 1:
332
+ return False
333
+ g = gcd(*factors.values())
334
+ if g == 1:
335
+ return False
336
+ return math.prod(p**(e//g) for p, e in factors.items()), g
337
+
338
+ # divide by 2
339
+ if next_p < 3:
340
+ g = bit_scan1(n)
341
+ if g:
342
+ if g == 1:
343
+ return False
344
+ n >>= g
345
+ factors[2] = g
346
+ if n == 1:
347
+ return 2, g
348
+ else:
349
+ # If `m**g`, then we have found perfect power.
350
+ # Otherwise, there is no possibility of perfect power, especially if `g` is prime.
351
+ m, _exact = iroot(n, g)
352
+ if _exact:
353
+ return 2*m, g
354
+ elif isprime(g):
355
+ return False
356
+ next_p = 3
357
+
358
+ # square number?
359
+ while n & 7 == 1: # n % 8 == 1:
360
+ m, _exact = iroot(n, 2)
361
+ if _exact:
362
+ n = m
363
+ multi <<= 1
364
+ else:
365
+ break
366
+ if n < next_p**3:
367
+ return done(n, factors, g, multi)
368
+
369
+ # trial factoring
370
+ # Since the maximum value an exponent can take is `log_{next_p}(n)`,
371
+ # the number of exponents to be checked can be reduced by performing a trial factoring.
372
+ # The value of `tf_max` needs more consideration.
373
+ tf_max = n.bit_length()//27 + 24
374
+ if next_p < tf_max:
375
+ for p in primerange(next_p, tf_max):
376
+ m, t = remove(n, p)
377
+ if t:
378
+ n = m
379
+ t *= multi
380
+ _g = gcd(g, t)
381
+ if _g == 1:
382
+ return False
383
+ factors[p] = t
384
+ if n == 1:
385
+ return math.prod(p**(e//_g)
386
+ for p, e in factors.items()), _g
387
+ elif g == 0 or _g < g: # If g is updated
388
+ g = _g
389
+ m, _exact = iroot(n**multi, g)
390
+ if _exact:
391
+ return m * math.prod(p**(e//g)
392
+ for p, e in factors.items()), g
393
+ elif isprime(g):
394
+ return False
395
+ next_p = tf_max
396
+ if n < next_p**3:
397
+ return done(n, factors, g, multi)
398
+
399
+ # check iroot
400
+ if g:
401
+ # If g is non-zero, the exponent is a divisor of g.
402
+ # 2 can be omitted since it has already been checked.
403
+ prime_iter = sorted(factorint(g >> bit_scan1(g)).keys())
404
+ else:
405
+ # The maximum possible value of the exponent is `log_{next_p}(n)`.
406
+ # To compensate for the presence of computational error, 2 is added.
407
+ prime_iter = primerange(3, int(math.log(n, next_p)) + 2)
408
+ logn = math.log2(n)
409
+ threshold = logn / 40 # Threshold for direct calculation
410
+ for p in prime_iter:
411
+ if threshold < p:
412
+ # If p is large, find the power root p directly without `iroot`.
413
+ while True:
414
+ b = pow(2, logn / p)
415
+ rb = int(b + 0.5)
416
+ if abs(rb - b) < 0.01 and rb**p == n:
417
+ n = rb
418
+ multi *= p
419
+ logn = math.log2(n)
420
+ else:
421
+ break
422
+ else:
423
+ while True:
424
+ m, _exact = iroot(n, p)
425
+ if _exact:
426
+ n = m
427
+ multi *= p
428
+ logn = math.log2(n)
429
+ else:
430
+ break
431
+ if n < next_p**(p + 2):
432
+ break
433
+ return done(n, factors, g, multi)
434
+
435
+
436
+ def perfect_power(n, candidates=None, big=True, factor=True):
437
+ """
438
+ Return ``(b, e)`` such that ``n`` == ``b**e`` if ``n`` is a unique
439
+ perfect power with ``e > 1``, else ``False`` (e.g. 1 is not a
440
+ perfect power). A ValueError is raised if ``n`` is not Rational.
441
+
442
+ By default, the base is recursively decomposed and the exponents
443
+ collected so the largest possible ``e`` is sought. If ``big=False``
444
+ then the smallest possible ``e`` (thus prime) will be chosen.
445
+
446
+ If ``factor=True`` then simultaneous factorization of ``n`` is
447
+ attempted since finding a factor indicates the only possible root
448
+ for ``n``. This is True by default since only a few small factors will
449
+ be tested in the course of searching for the perfect power.
450
+
451
+ The use of ``candidates`` is primarily for internal use; if provided,
452
+ False will be returned if ``n`` cannot be written as a power with one
453
+ of the candidates as an exponent and factoring (beyond testing for
454
+ a factor of 2) will not be attempted.
455
+
456
+ Examples
457
+ ========
458
+
459
+ >>> from sympy import perfect_power, Rational
460
+ >>> perfect_power(16)
461
+ (2, 4)
462
+ >>> perfect_power(16, big=False)
463
+ (4, 2)
464
+
465
+ Negative numbers can only have odd perfect powers:
466
+
467
+ >>> perfect_power(-4)
468
+ False
469
+ >>> perfect_power(-8)
470
+ (-2, 3)
471
+
472
+ Rationals are also recognized:
473
+
474
+ >>> perfect_power(Rational(1, 2)**3)
475
+ (1/2, 3)
476
+ >>> perfect_power(Rational(-3, 2)**3)
477
+ (-3/2, 3)
478
+
479
+ Notes
480
+ =====
481
+
482
+ To know whether an integer is a perfect power of 2 use
483
+
484
+ >>> is2pow = lambda n: bool(n and not n & (n - 1))
485
+ >>> [(i, is2pow(i)) for i in range(5)]
486
+ [(0, False), (1, True), (2, True), (3, False), (4, True)]
487
+
488
+ It is not necessary to provide ``candidates``. When provided
489
+ it will be assumed that they are ints. The first one that is
490
+ larger than the computed maximum possible exponent will signal
491
+ failure for the routine.
492
+
493
+ >>> perfect_power(3**8, [9])
494
+ False
495
+ >>> perfect_power(3**8, [2, 4, 8])
496
+ (3, 8)
497
+ >>> perfect_power(3**8, [4, 8], big=False)
498
+ (9, 4)
499
+
500
+ See Also
501
+ ========
502
+ sympy.core.intfunc.integer_nthroot
503
+ sympy.ntheory.primetest.is_square
504
+ """
505
+ if isinstance(n, Rational) and not n.is_Integer:
506
+ p, q = n.as_numer_denom()
507
+ if p is S.One:
508
+ pp = perfect_power(q)
509
+ if pp:
510
+ pp = (n.func(1, pp[0]), pp[1])
511
+ else:
512
+ pp = perfect_power(p)
513
+ if pp:
514
+ num, e = pp
515
+ pq = perfect_power(q, [e])
516
+ if pq:
517
+ den, _ = pq
518
+ pp = n.func(num, den), e
519
+ return pp
520
+
521
+ n = as_int(n)
522
+ if n < 0:
523
+ pp = perfect_power(-n)
524
+ if pp:
525
+ b, e = pp
526
+ if e % 2:
527
+ return -b, e
528
+ return False
529
+
530
+ if candidates is None and big:
531
+ return _perfect_power(n)
532
+
533
+ if n <= 3:
534
+ # no unique exponent for 0, 1
535
+ # 2 and 3 have exponents of 1
536
+ return False
537
+ logn = math.log2(n)
538
+ max_possible = int(logn) + 2 # only check values less than this
539
+ not_square = n % 10 in [2, 3, 7, 8] # squares cannot end in 2, 3, 7, 8
540
+ min_possible = 2 + not_square
541
+ if not candidates:
542
+ candidates = primerange(min_possible, max_possible)
543
+ else:
544
+ candidates = sorted([i for i in candidates
545
+ if min_possible <= i < max_possible])
546
+ if n%2 == 0:
547
+ e = bit_scan1(n)
548
+ candidates = [i for i in candidates if e%i == 0]
549
+ if big:
550
+ candidates = reversed(candidates)
551
+ for e in candidates:
552
+ r, ok = iroot(n, e)
553
+ if ok:
554
+ return int(r), e
555
+ return False
556
+
557
+ def _factors():
558
+ rv = 2 + n % 2
559
+ while True:
560
+ yield rv
561
+ rv = nextprime(rv)
562
+
563
+ for fac, e in zip(_factors(), candidates):
564
+ # see if there is a factor present
565
+ if factor and n % fac == 0:
566
+ # find what the potential power is
567
+ e = remove(n, fac)[1]
568
+ # if it's a trivial power we are done
569
+ if e == 1:
570
+ return False
571
+
572
+ # maybe the e-th root of n is exact
573
+ r, exact = iroot(n, e)
574
+ if not exact:
575
+ # Having a factor, we know that e is the maximal
576
+ # possible value for a root of n.
577
+ # If n = fac**e*m can be written as a perfect
578
+ # power then see if m can be written as r**E where
579
+ # gcd(e, E) != 1 so n = (fac**(e//E)*r)**E
580
+ m = n//fac**e
581
+ rE = perfect_power(m, candidates=divisors(e, generator=True))
582
+ if not rE:
583
+ return False
584
+ else:
585
+ r, E = rE
586
+ r, e = fac**(e//E)*r, E
587
+ if not big:
588
+ e0 = primefactors(e)
589
+ if e0[0] != e:
590
+ r, e = r**(e//e0[0]), e0[0]
591
+ return int(r), e
592
+
593
+ # Weed out downright impossible candidates
594
+ if logn/e < 40:
595
+ b = 2.0**(logn/e)
596
+ if abs(int(b + 0.5) - b) > 0.01:
597
+ continue
598
+
599
+ # now see if the plausible e makes a perfect power
600
+ r, exact = iroot(n, e)
601
+ if exact:
602
+ if big:
603
+ m = perfect_power(r, big=big, factor=factor)
604
+ if m:
605
+ r, e = m[0], e*m[1]
606
+ return int(r), e
607
+
608
+ return False
609
+
610
+
611
+ def pollard_rho(n, s=2, a=1, retries=5, seed=1234, max_steps=None, F=None):
612
+ r"""
613
+ Use Pollard's rho method to try to extract a nontrivial factor
614
+ of ``n``. The returned factor may be a composite number. If no
615
+ factor is found, ``None`` is returned.
616
+
617
+ The algorithm generates pseudo-random values of x with a generator
618
+ function, replacing x with F(x). If F is not supplied then the
619
+ function x**2 + ``a`` is used. The first value supplied to F(x) is ``s``.
620
+ Upon failure (if ``retries`` is > 0) a new ``a`` and ``s`` will be
621
+ supplied; the ``a`` will be ignored if F was supplied.
622
+
623
+ The sequence of numbers generated by such functions generally have a
624
+ a lead-up to some number and then loop around back to that number and
625
+ begin to repeat the sequence, e.g. 1, 2, 3, 4, 5, 3, 4, 5 -- this leader
626
+ and loop look a bit like the Greek letter rho, and thus the name, 'rho'.
627
+
628
+ For a given function, very different leader-loop values can be obtained
629
+ so it is a good idea to allow for retries:
630
+
631
+ >>> from sympy.ntheory.generate import cycle_length
632
+ >>> n = 16843009
633
+ >>> F = lambda x:(2048*pow(x, 2, n) + 32767) % n
634
+ >>> for s in range(5):
635
+ ... print('loop length = %4i; leader length = %3i' % next(cycle_length(F, s)))
636
+ ...
637
+ loop length = 2489; leader length = 43
638
+ loop length = 78; leader length = 121
639
+ loop length = 1482; leader length = 100
640
+ loop length = 1482; leader length = 286
641
+ loop length = 1482; leader length = 101
642
+
643
+ Here is an explicit example where there is a three element leadup to
644
+ a sequence of 3 numbers (11, 14, 4) that then repeat:
645
+
646
+ >>> x=2
647
+ >>> for i in range(9):
648
+ ... print(x)
649
+ ... x=(x**2+12)%17
650
+ ...
651
+ 2
652
+ 16
653
+ 13
654
+ 11
655
+ 14
656
+ 4
657
+ 11
658
+ 14
659
+ 4
660
+ >>> next(cycle_length(lambda x: (x**2+12)%17, 2))
661
+ (3, 3)
662
+ >>> list(cycle_length(lambda x: (x**2+12)%17, 2, values=True))
663
+ [2, 16, 13, 11, 14, 4]
664
+
665
+ Instead of checking the differences of all generated values for a gcd
666
+ with n, only the kth and 2*kth numbers are checked, e.g. 1st and 2nd,
667
+ 2nd and 4th, 3rd and 6th until it has been detected that the loop has been
668
+ traversed. Loops may be many thousands of steps long before rho finds a
669
+ factor or reports failure. If ``max_steps`` is specified, the iteration
670
+ is cancelled with a failure after the specified number of steps.
671
+
672
+ Examples
673
+ ========
674
+
675
+ >>> from sympy import pollard_rho
676
+ >>> n=16843009
677
+ >>> F=lambda x:(2048*pow(x,2,n) + 32767) % n
678
+ >>> pollard_rho(n, F=F)
679
+ 257
680
+
681
+ Use the default setting with a bad value of ``a`` and no retries:
682
+
683
+ >>> pollard_rho(n, a=n-2, retries=0)
684
+
685
+ If retries is > 0 then perhaps the problem will correct itself when
686
+ new values are generated for a:
687
+
688
+ >>> pollard_rho(n, a=n-2, retries=1)
689
+ 257
690
+
691
+ References
692
+ ==========
693
+
694
+ .. [1] Richard Crandall & Carl Pomerance (2005), "Prime Numbers:
695
+ A Computational Perspective", Springer, 2nd edition, 229-231
696
+
697
+ """
698
+ n = int(n)
699
+ if n < 5:
700
+ raise ValueError('pollard_rho should receive n > 4')
701
+ randint = _randint(seed + retries)
702
+ V = s
703
+ for i in range(retries + 1):
704
+ U = V
705
+ if not F:
706
+ F = lambda x: (pow(x, 2, n) + a) % n
707
+ j = 0
708
+ while 1:
709
+ if max_steps and (j > max_steps):
710
+ break
711
+ j += 1
712
+ U = F(U)
713
+ V = F(F(V)) # V is 2x further along than U
714
+ g = gcd(U - V, n)
715
+ if g == 1:
716
+ continue
717
+ if g == n:
718
+ break
719
+ return int(g)
720
+ V = randint(0, n - 1)
721
+ a = randint(1, n - 3) # for x**2 + a, a%n should not be 0 or -2
722
+ F = None
723
+ return None
724
+
725
+
726
+ def pollard_pm1(n, B=10, a=2, retries=0, seed=1234):
727
+ """
728
+ Use Pollard's p-1 method to try to extract a nontrivial factor
729
+ of ``n``. Either a divisor (perhaps composite) or ``None`` is returned.
730
+
731
+ The value of ``a`` is the base that is used in the test gcd(a**M - 1, n).
732
+ The default is 2. If ``retries`` > 0 then if no factor is found after the
733
+ first attempt, a new ``a`` will be generated randomly (using the ``seed``)
734
+ and the process repeated.
735
+
736
+ Note: the value of M is lcm(1..B) = reduce(ilcm, range(2, B + 1)).
737
+
738
+ A search is made for factors next to even numbers having a power smoothness
739
+ less than ``B``. Choosing a larger B increases the likelihood of finding a
740
+ larger factor but takes longer. Whether a factor of n is found or not
741
+ depends on ``a`` and the power smoothness of the even number just less than
742
+ the factor p (hence the name p - 1).
743
+
744
+ Although some discussion of what constitutes a good ``a`` some
745
+ descriptions are hard to interpret. At the modular.math site referenced
746
+ below it is stated that if gcd(a**M - 1, n) = N then a**M % q**r is 1
747
+ for every prime power divisor of N. But consider the following:
748
+
749
+ >>> from sympy.ntheory.factor_ import smoothness_p, pollard_pm1
750
+ >>> n=257*1009
751
+ >>> smoothness_p(n)
752
+ (-1, [(257, (1, 2, 256)), (1009, (1, 7, 16))])
753
+
754
+ So we should (and can) find a root with B=16:
755
+
756
+ >>> pollard_pm1(n, B=16, a=3)
757
+ 1009
758
+
759
+ If we attempt to increase B to 256 we find that it does not work:
760
+
761
+ >>> pollard_pm1(n, B=256)
762
+ >>>
763
+
764
+ But if the value of ``a`` is changed we find that only multiples of
765
+ 257 work, e.g.:
766
+
767
+ >>> pollard_pm1(n, B=256, a=257)
768
+ 1009
769
+
770
+ Checking different ``a`` values shows that all the ones that did not
771
+ work had a gcd value not equal to ``n`` but equal to one of the
772
+ factors:
773
+
774
+ >>> from sympy import ilcm, igcd, factorint, Pow
775
+ >>> M = 1
776
+ >>> for i in range(2, 256):
777
+ ... M = ilcm(M, i)
778
+ ...
779
+ >>> set([igcd(pow(a, M, n) - 1, n) for a in range(2, 256) if
780
+ ... igcd(pow(a, M, n) - 1, n) != n])
781
+ {1009}
782
+
783
+ But does aM % d for every divisor of n give 1?
784
+
785
+ >>> aM = pow(255, M, n)
786
+ >>> [(d, aM%Pow(*d.args)) for d in factorint(n, visual=True).args]
787
+ [(257**1, 1), (1009**1, 1)]
788
+
789
+ No, only one of them. So perhaps the principle is that a root will
790
+ be found for a given value of B provided that:
791
+
792
+ 1) the power smoothness of the p - 1 value next to the root
793
+ does not exceed B
794
+ 2) a**M % p != 1 for any of the divisors of n.
795
+
796
+ By trying more than one ``a`` it is possible that one of them
797
+ will yield a factor.
798
+
799
+ Examples
800
+ ========
801
+
802
+ With the default smoothness bound, this number cannot be cracked:
803
+
804
+ >>> from sympy.ntheory import pollard_pm1
805
+ >>> pollard_pm1(21477639576571)
806
+
807
+ Increasing the smoothness bound helps:
808
+
809
+ >>> pollard_pm1(21477639576571, B=2000)
810
+ 4410317
811
+
812
+ Looking at the smoothness of the factors of this number we find:
813
+
814
+ >>> from sympy.ntheory.factor_ import smoothness_p, factorint
815
+ >>> print(smoothness_p(21477639576571, visual=1))
816
+ p**i=4410317**1 has p-1 B=1787, B-pow=1787
817
+ p**i=4869863**1 has p-1 B=2434931, B-pow=2434931
818
+
819
+ The B and B-pow are the same for the p - 1 factorizations of the divisors
820
+ because those factorizations had a very large prime factor:
821
+
822
+ >>> factorint(4410317 - 1)
823
+ {2: 2, 617: 1, 1787: 1}
824
+ >>> factorint(4869863-1)
825
+ {2: 1, 2434931: 1}
826
+
827
+ Note that until B reaches the B-pow value of 1787, the number is not cracked;
828
+
829
+ >>> pollard_pm1(21477639576571, B=1786)
830
+ >>> pollard_pm1(21477639576571, B=1787)
831
+ 4410317
832
+
833
+ The B value has to do with the factors of the number next to the divisor,
834
+ not the divisors themselves. A worst case scenario is that the number next
835
+ to the factor p has a large prime divisisor or is a perfect power. If these
836
+ conditions apply then the power-smoothness will be about p/2 or p. The more
837
+ realistic is that there will be a large prime factor next to p requiring
838
+ a B value on the order of p/2. Although primes may have been searched for
839
+ up to this level, the p/2 is a factor of p - 1, something that we do not
840
+ know. The modular.math reference below states that 15% of numbers in the
841
+ range of 10**15 to 15**15 + 10**4 are 10**6 power smooth so a B of 10**6
842
+ will fail 85% of the time in that range. From 10**8 to 10**8 + 10**3 the
843
+ percentages are nearly reversed...but in that range the simple trial
844
+ division is quite fast.
845
+
846
+ References
847
+ ==========
848
+
849
+ .. [1] Richard Crandall & Carl Pomerance (2005), "Prime Numbers:
850
+ A Computational Perspective", Springer, 2nd edition, 236-238
851
+ .. [2] https://web.archive.org/web/20150716201437/http://modular.math.washington.edu/edu/2007/spring/ent/ent-html/node81.html
852
+ .. [3] https://www.cs.toronto.edu/~yuvalf/Factorization.pdf
853
+ """
854
+
855
+ n = int(n)
856
+ if n < 4 or B < 3:
857
+ raise ValueError('pollard_pm1 should receive n > 3 and B > 2')
858
+ randint = _randint(seed + B)
859
+
860
+ # computing a**lcm(1,2,3,..B) % n for B > 2
861
+ # it looks weird, but it's right: primes run [2, B]
862
+ # and the answer's not right until the loop is done.
863
+ for i in range(retries + 1):
864
+ aM = a
865
+ for p in sieve.primerange(2, B + 1):
866
+ e = int(math.log(B, p))
867
+ aM = pow(aM, pow(p, e), n)
868
+ g = gcd(aM - 1, n)
869
+ if 1 < g < n:
870
+ return int(g)
871
+
872
+ # get a new a:
873
+ # since the exponent, lcm(1..B), is even, if we allow 'a' to be 'n-1'
874
+ # then (n - 1)**even % n will be 1 which will give a g of 0 and 1 will
875
+ # give a zero, too, so we set the range as [2, n-2]. Some references
876
+ # say 'a' should be coprime to n, but either will detect factors.
877
+ a = randint(2, n - 2)
878
+
879
+
880
+ def _trial(factors, n, candidates, verbose=False):
881
+ """
882
+ Helper function for integer factorization. Trial factors ``n`
883
+ against all integers given in the sequence ``candidates``
884
+ and updates the dict ``factors`` in-place. Returns the reduced
885
+ value of ``n`` and a flag indicating whether any factors were found.
886
+ """
887
+ if verbose:
888
+ factors0 = list(factors.keys())
889
+ nfactors = len(factors)
890
+ for d in candidates:
891
+ if n % d == 0:
892
+ n, m = remove(n // d, d)
893
+ factors[d] = m + 1
894
+ if verbose:
895
+ for k in sorted(set(factors).difference(set(factors0))):
896
+ print(factor_msg % (k, factors[k]))
897
+ return int(n), len(factors) != nfactors
898
+
899
+
900
+ def _check_termination(factors, n, limit, use_trial, use_rho, use_pm1,
901
+ verbose, next_p):
902
+ """
903
+ Helper function for integer factorization. Checks if ``n``
904
+ is a prime or a perfect power, and in those cases updates the factorization.
905
+ """
906
+ if verbose:
907
+ print('Check for termination')
908
+ if n == 1:
909
+ if verbose:
910
+ print(complete_msg)
911
+ return True
912
+ if n < next_p**2 or isprime(n):
913
+ factors[int(n)] = 1
914
+ if verbose:
915
+ print(complete_msg)
916
+ return True
917
+
918
+ # since we've already been factoring there is no need to do
919
+ # simultaneous factoring with the power check
920
+ p = _perfect_power(n, next_p)
921
+ if not p:
922
+ return False
923
+ base, exp = p
924
+ if base < next_p**2 or isprime(base):
925
+ factors[base] = exp
926
+ else:
927
+ facs = factorint(base, limit, use_trial, use_rho, use_pm1,
928
+ verbose=False)
929
+ for b, e in facs.items():
930
+ if verbose:
931
+ print(factor_msg % (b, e))
932
+ # int() can be removed when https://github.com/flintlib/python-flint/issues/92 is resolved
933
+ factors[b] = int(exp*e)
934
+ if verbose:
935
+ print(complete_msg)
936
+ return True
937
+
938
+
939
+ trial_int_msg = "Trial division with ints [%i ... %i] and fail_max=%i"
940
+ trial_msg = "Trial division with primes [%i ... %i]"
941
+ rho_msg = "Pollard's rho with retries %i, max_steps %i and seed %i"
942
+ pm1_msg = "Pollard's p-1 with smoothness bound %i and seed %i"
943
+ ecm_msg = "Elliptic Curve with B1 bound %i, B2 bound %i, num_curves %i"
944
+ factor_msg = '\t%i ** %i'
945
+ fermat_msg = 'Close factors satisying Fermat condition found.'
946
+ complete_msg = 'Factorization is complete.'
947
+
948
+
949
+ def _factorint_small(factors, n, limit, fail_max, next_p=2):
950
+ """
951
+ Return the value of n and either a 0 (indicating that factorization up
952
+ to the limit was complete) or else the next near-prime that would have
953
+ been tested.
954
+
955
+ Factoring stops if there are fail_max unsuccessful tests in a row.
956
+
957
+ If factors of n were found they will be in the factors dictionary as
958
+ {factor: multiplicity} and the returned value of n will have had those
959
+ factors removed. The factors dictionary is modified in-place.
960
+
961
+ """
962
+
963
+ def done(n, d):
964
+ """return n, d if the sqrt(n) was not reached yet, else
965
+ n, 0 indicating that factoring is done.
966
+ """
967
+ if d*d <= n:
968
+ return n, d
969
+ return n, 0
970
+
971
+ limit2 = limit**2
972
+ threshold2 = min(n, limit2)
973
+
974
+ if next_p < 3:
975
+ if not n & 1:
976
+ m = bit_scan1(n)
977
+ factors[2] = m
978
+ n >>= m
979
+ threshold2 = min(n, limit2)
980
+ next_p = 3
981
+ if threshold2 < 9: # next_p**2 = 9
982
+ return done(n, next_p)
983
+
984
+ if next_p < 5:
985
+ if not n % 3:
986
+ n //= 3
987
+ m = 1
988
+ while not n % 3:
989
+ n //= 3
990
+ m += 1
991
+ if m == 20:
992
+ n, mm = remove(n, 3)
993
+ m += mm
994
+ break
995
+ factors[3] = m
996
+ threshold2 = min(n, limit2)
997
+ next_p = 5
998
+ if threshold2 < 25: # next_p**2 = 25
999
+ return done(n, next_p)
1000
+
1001
+ # Because of the order of checks, starting from `min_p = 6k+5`,
1002
+ # useless checks are caused.
1003
+ # We want to calculate
1004
+ # next_p += [-1, -2, 3, 2, 1, 0][next_p % 6]
1005
+ p6 = next_p % 6
1006
+ next_p += (-1 if p6 < 2 else 5) - p6
1007
+
1008
+ fails = 0
1009
+ while fails < fail_max:
1010
+ # next_p % 6 == 5
1011
+ if n % next_p:
1012
+ fails += 1
1013
+ else:
1014
+ n //= next_p
1015
+ m = 1
1016
+ while not n % next_p:
1017
+ n //= next_p
1018
+ m += 1
1019
+ if m == 20:
1020
+ n, mm = remove(n, next_p)
1021
+ m += mm
1022
+ break
1023
+ factors[next_p] = m
1024
+ fails = 0
1025
+ threshold2 = min(n, limit2)
1026
+ next_p += 2
1027
+ if threshold2 < next_p**2:
1028
+ return done(n, next_p)
1029
+
1030
+ # next_p % 6 == 1
1031
+ if n % next_p:
1032
+ fails += 1
1033
+ else:
1034
+ n //= next_p
1035
+ m = 1
1036
+ while not n % next_p:
1037
+ n //= next_p
1038
+ m += 1
1039
+ if m == 20:
1040
+ n, mm = remove(n, next_p)
1041
+ m += mm
1042
+ break
1043
+ factors[next_p] = m
1044
+ fails = 0
1045
+ threshold2 = min(n, limit2)
1046
+ next_p += 4
1047
+ if threshold2 < next_p**2:
1048
+ return done(n, next_p)
1049
+ return done(n, next_p)
1050
+
1051
+
1052
+ def factorint(n, limit=None, use_trial=True, use_rho=True, use_pm1=True,
1053
+ use_ecm=True, verbose=False, visual=None, multiple=False):
1054
+ r"""
1055
+ Given a positive integer ``n``, ``factorint(n)`` returns a dict containing
1056
+ the prime factors of ``n`` as keys and their respective multiplicities
1057
+ as values. For example:
1058
+
1059
+ >>> from sympy.ntheory import factorint
1060
+ >>> factorint(2000) # 2000 = (2**4) * (5**3)
1061
+ {2: 4, 5: 3}
1062
+ >>> factorint(65537) # This number is prime
1063
+ {65537: 1}
1064
+
1065
+ For input less than 2, factorint behaves as follows:
1066
+
1067
+ - ``factorint(1)`` returns the empty factorization, ``{}``
1068
+ - ``factorint(0)`` returns ``{0:1}``
1069
+ - ``factorint(-n)`` adds ``-1:1`` to the factors and then factors ``n``
1070
+
1071
+ Partial Factorization:
1072
+
1073
+ If ``limit`` (> 3) is specified, the search is stopped after performing
1074
+ trial division up to (and including) the limit (or taking a
1075
+ corresponding number of rho/p-1 steps). This is useful if one has
1076
+ a large number and only is interested in finding small factors (if
1077
+ any). Note that setting a limit does not prevent larger factors
1078
+ from being found early; it simply means that the largest factor may
1079
+ be composite. Since checking for perfect power is relatively cheap, it is
1080
+ done regardless of the limit setting.
1081
+
1082
+ This number, for example, has two small factors and a huge
1083
+ semi-prime factor that cannot be reduced easily:
1084
+
1085
+ >>> from sympy.ntheory import isprime
1086
+ >>> a = 1407633717262338957430697921446883
1087
+ >>> f = factorint(a, limit=10000)
1088
+ >>> f == {991: 1, int(202916782076162456022877024859): 1, 7: 1}
1089
+ True
1090
+ >>> isprime(max(f))
1091
+ False
1092
+
1093
+ This number has a small factor and a residual perfect power whose
1094
+ base is greater than the limit:
1095
+
1096
+ >>> factorint(3*101**7, limit=5)
1097
+ {3: 1, 101: 7}
1098
+
1099
+ List of Factors:
1100
+
1101
+ If ``multiple`` is set to ``True`` then a list containing the
1102
+ prime factors including multiplicities is returned.
1103
+
1104
+ >>> factorint(24, multiple=True)
1105
+ [2, 2, 2, 3]
1106
+
1107
+ Visual Factorization:
1108
+
1109
+ If ``visual`` is set to ``True``, then it will return a visual
1110
+ factorization of the integer. For example:
1111
+
1112
+ >>> from sympy import pprint
1113
+ >>> pprint(factorint(4200, visual=True))
1114
+ 3 1 2 1
1115
+ 2 *3 *5 *7
1116
+
1117
+ Note that this is achieved by using the evaluate=False flag in Mul
1118
+ and Pow. If you do other manipulations with an expression where
1119
+ evaluate=False, it may evaluate. Therefore, you should use the
1120
+ visual option only for visualization, and use the normal dictionary
1121
+ returned by visual=False if you want to perform operations on the
1122
+ factors.
1123
+
1124
+ You can easily switch between the two forms by sending them back to
1125
+ factorint:
1126
+
1127
+ >>> from sympy import Mul
1128
+ >>> regular = factorint(1764); regular
1129
+ {2: 2, 3: 2, 7: 2}
1130
+ >>> pprint(factorint(regular))
1131
+ 2 2 2
1132
+ 2 *3 *7
1133
+
1134
+ >>> visual = factorint(1764, visual=True); pprint(visual)
1135
+ 2 2 2
1136
+ 2 *3 *7
1137
+ >>> print(factorint(visual))
1138
+ {2: 2, 3: 2, 7: 2}
1139
+
1140
+ If you want to send a number to be factored in a partially factored form
1141
+ you can do so with a dictionary or unevaluated expression:
1142
+
1143
+ >>> factorint(factorint({4: 2, 12: 3})) # twice to toggle to dict form
1144
+ {2: 10, 3: 3}
1145
+ >>> factorint(Mul(4, 12, evaluate=False))
1146
+ {2: 4, 3: 1}
1147
+
1148
+ The table of the output logic is:
1149
+
1150
+ ====== ====== ======= =======
1151
+ Visual
1152
+ ------ ----------------------
1153
+ Input True False other
1154
+ ====== ====== ======= =======
1155
+ dict mul dict mul
1156
+ n mul dict dict
1157
+ mul mul dict dict
1158
+ ====== ====== ======= =======
1159
+
1160
+ Notes
1161
+ =====
1162
+
1163
+ Algorithm:
1164
+
1165
+ The function switches between multiple algorithms. Trial division
1166
+ quickly finds small factors (of the order 1-5 digits), and finds
1167
+ all large factors if given enough time. The Pollard rho and p-1
1168
+ algorithms are used to find large factors ahead of time; they
1169
+ will often find factors of the order of 10 digits within a few
1170
+ seconds:
1171
+
1172
+ >>> factors = factorint(12345678910111213141516)
1173
+ >>> for base, exp in sorted(factors.items()):
1174
+ ... print('%s %s' % (base, exp))
1175
+ ...
1176
+ 2 2
1177
+ 2507191691 1
1178
+ 1231026625769 1
1179
+
1180
+ Any of these methods can optionally be disabled with the following
1181
+ boolean parameters:
1182
+
1183
+ - ``use_trial``: Toggle use of trial division
1184
+ - ``use_rho``: Toggle use of Pollard's rho method
1185
+ - ``use_pm1``: Toggle use of Pollard's p-1 method
1186
+
1187
+ ``factorint`` also periodically checks if the remaining part is
1188
+ a prime number or a perfect power, and in those cases stops.
1189
+
1190
+ For unevaluated factorial, it uses Legendre's formula(theorem).
1191
+
1192
+
1193
+ If ``verbose`` is set to ``True``, detailed progress is printed.
1194
+
1195
+ See Also
1196
+ ========
1197
+
1198
+ smoothness, smoothness_p, divisors
1199
+
1200
+ """
1201
+ if isinstance(n, Dict):
1202
+ n = dict(n)
1203
+ if multiple:
1204
+ fac = factorint(n, limit=limit, use_trial=use_trial,
1205
+ use_rho=use_rho, use_pm1=use_pm1,
1206
+ verbose=verbose, visual=False, multiple=False)
1207
+ factorlist = sum(([p] * fac[p] if fac[p] > 0 else [S.One/p]*(-fac[p])
1208
+ for p in sorted(fac)), [])
1209
+ return factorlist
1210
+
1211
+ factordict = {}
1212
+ if visual and not isinstance(n, (Mul, dict)):
1213
+ factordict = factorint(n, limit=limit, use_trial=use_trial,
1214
+ use_rho=use_rho, use_pm1=use_pm1,
1215
+ verbose=verbose, visual=False)
1216
+ elif isinstance(n, Mul):
1217
+ factordict = {int(k): int(v) for k, v in
1218
+ n.as_powers_dict().items()}
1219
+ elif isinstance(n, dict):
1220
+ factordict = n
1221
+ if factordict and isinstance(n, (Mul, dict)):
1222
+ # check it
1223
+ for key in list(factordict.keys()):
1224
+ if isprime(key):
1225
+ continue
1226
+ e = factordict.pop(key)
1227
+ d = factorint(key, limit=limit, use_trial=use_trial, use_rho=use_rho,
1228
+ use_pm1=use_pm1, verbose=verbose, visual=False)
1229
+ for k, v in d.items():
1230
+ if k in factordict:
1231
+ factordict[k] += v*e
1232
+ else:
1233
+ factordict[k] = v*e
1234
+ if visual or (type(n) is dict and
1235
+ visual is not True and
1236
+ visual is not False):
1237
+ if factordict == {}:
1238
+ return S.One
1239
+ if -1 in factordict:
1240
+ factordict.pop(-1)
1241
+ args = [S.NegativeOne]
1242
+ else:
1243
+ args = []
1244
+ args.extend([Pow(*i, evaluate=False)
1245
+ for i in sorted(factordict.items())])
1246
+ return Mul(*args, evaluate=False)
1247
+ elif isinstance(n, (dict, Mul)):
1248
+ return factordict
1249
+
1250
+ assert use_trial or use_rho or use_pm1 or use_ecm
1251
+
1252
+ from sympy.functions.combinatorial.factorials import factorial
1253
+ if isinstance(n, factorial):
1254
+ x = as_int(n.args[0])
1255
+ if x >= 20:
1256
+ factors = {}
1257
+ m = 2 # to initialize the if condition below
1258
+ for p in sieve.primerange(2, x + 1):
1259
+ if m > 1:
1260
+ m, q = 0, x // p
1261
+ while q != 0:
1262
+ m += q
1263
+ q //= p
1264
+ factors[p] = m
1265
+ if factors and verbose:
1266
+ for k in sorted(factors):
1267
+ print(factor_msg % (k, factors[k]))
1268
+ if verbose:
1269
+ print(complete_msg)
1270
+ return factors
1271
+ else:
1272
+ # if n < 20!, direct computation is faster
1273
+ # since it uses a lookup table
1274
+ n = n.func(x)
1275
+
1276
+ n = as_int(n)
1277
+ if limit:
1278
+ limit = int(limit)
1279
+ use_ecm = False
1280
+
1281
+ # special cases
1282
+ if n < 0:
1283
+ factors = factorint(
1284
+ -n, limit=limit, use_trial=use_trial, use_rho=use_rho,
1285
+ use_pm1=use_pm1, verbose=verbose, visual=False)
1286
+ factors[-1] = 1
1287
+ return factors
1288
+
1289
+ if limit and limit < 2:
1290
+ if n == 1:
1291
+ return {}
1292
+ return {n: 1}
1293
+ elif n < 10:
1294
+ # doing this we are assured of getting a limit > 2
1295
+ # when we have to compute it later
1296
+ return [{0: 1}, {}, {2: 1}, {3: 1}, {2: 2}, {5: 1},
1297
+ {2: 1, 3: 1}, {7: 1}, {2: 3}, {3: 2}][n]
1298
+
1299
+ factors = {}
1300
+
1301
+ # do simplistic factorization
1302
+ if verbose:
1303
+ sn = str(n)
1304
+ if len(sn) > 50:
1305
+ print('Factoring %s' % sn[:5] + \
1306
+ '..(%i other digits)..' % (len(sn) - 10) + sn[-5:])
1307
+ else:
1308
+ print('Factoring', n)
1309
+
1310
+ # this is the preliminary factorization for small factors
1311
+ # We want to guarantee that there are no small prime factors,
1312
+ # so we run even if `use_trial` is False.
1313
+ small = 2**15
1314
+ fail_max = 600
1315
+ small = min(small, limit or small)
1316
+ if verbose:
1317
+ print(trial_int_msg % (2, small, fail_max))
1318
+ n, next_p = _factorint_small(factors, n, small, fail_max)
1319
+ if factors and verbose:
1320
+ for k in sorted(factors):
1321
+ print(factor_msg % (k, factors[k]))
1322
+ if next_p == 0:
1323
+ if n > 1:
1324
+ factors[int(n)] = 1
1325
+ if verbose:
1326
+ print(complete_msg)
1327
+ return factors
1328
+ # first check if the simplistic run didn't finish
1329
+ # because of the limit and check for a perfect
1330
+ # power before exiting
1331
+ if limit and next_p > limit:
1332
+ if verbose:
1333
+ print('Exceeded limit:', limit)
1334
+ if _check_termination(factors, n, limit, use_trial,
1335
+ use_rho, use_pm1, verbose, next_p):
1336
+ return factors
1337
+ if n > 1:
1338
+ factors[int(n)] = 1
1339
+ return factors
1340
+ if _check_termination(factors, n, limit, use_trial,
1341
+ use_rho, use_pm1, verbose, next_p):
1342
+ return factors
1343
+
1344
+ # continue with more advanced factorization methods
1345
+ # ...do a Fermat test since it's so easy and we need the
1346
+ # square root anyway. Finding 2 factors is easy if they are
1347
+ # "close enough." This is the big root equivalent of dividing by
1348
+ # 2, 3, 5.
1349
+ sqrt_n = isqrt(n)
1350
+ a = sqrt_n + 1
1351
+ # If `n % 4 == 1`, `a` must be odd for `a**2 - n` to be a square number.
1352
+ if (n % 4 == 1) ^ (a & 1):
1353
+ a += 1
1354
+ a2 = a**2
1355
+ b2 = a2 - n
1356
+ for _ in range(3):
1357
+ b, fermat = sqrtrem(b2)
1358
+ if not fermat:
1359
+ if verbose:
1360
+ print(fermat_msg)
1361
+ for r in [a - b, a + b]:
1362
+ facs = factorint(r, limit=limit, use_trial=use_trial,
1363
+ use_rho=use_rho, use_pm1=use_pm1,
1364
+ verbose=verbose)
1365
+ for k, v in facs.items():
1366
+ factors[k] = factors.get(k, 0) + v
1367
+ if verbose:
1368
+ print(complete_msg)
1369
+ return factors
1370
+ b2 += (a + 1) << 2 # equiv to (a + 2)**2 - n
1371
+ a += 2
1372
+
1373
+ # these are the limits for trial division which will
1374
+ # be attempted in parallel with pollard methods
1375
+ low, high = next_p, 2*next_p
1376
+
1377
+ # add 1 to make sure limit is reached in primerange calls
1378
+ _limit = (limit or sqrt_n) + 1
1379
+ iteration = 0
1380
+ while 1:
1381
+ high_ = min(high, _limit)
1382
+
1383
+ # Trial division
1384
+ if use_trial:
1385
+ if verbose:
1386
+ print(trial_msg % (low, high_))
1387
+ ps = sieve.primerange(low, high_)
1388
+ n, found_trial = _trial(factors, n, ps, verbose)
1389
+ next_p = high_
1390
+ if found_trial and _check_termination(factors, n, limit, use_trial,
1391
+ use_rho, use_pm1, verbose, next_p):
1392
+ return factors
1393
+ else:
1394
+ found_trial = False
1395
+
1396
+ if high > _limit:
1397
+ if verbose:
1398
+ print('Exceeded limit:', _limit)
1399
+ if n > 1:
1400
+ factors[int(n)] = 1
1401
+ if verbose:
1402
+ print(complete_msg)
1403
+ return factors
1404
+
1405
+ # Only used advanced methods when no small factors were found
1406
+ if not found_trial:
1407
+ # Pollard p-1
1408
+ if use_pm1:
1409
+ if verbose:
1410
+ print(pm1_msg % (low, high_))
1411
+ c = pollard_pm1(n, B=low, seed=high_)
1412
+ if c:
1413
+ if c < next_p**2 or isprime(c):
1414
+ ps = [c]
1415
+ else:
1416
+ ps = factorint(c, limit=limit,
1417
+ use_trial=use_trial,
1418
+ use_rho=use_rho,
1419
+ use_pm1=use_pm1,
1420
+ use_ecm=use_ecm,
1421
+ verbose=verbose)
1422
+ n, _ = _trial(factors, n, ps, verbose=False)
1423
+ if _check_termination(factors, n, limit, use_trial,
1424
+ use_rho, use_pm1, verbose, next_p):
1425
+ return factors
1426
+
1427
+ # Pollard rho
1428
+ if use_rho:
1429
+ if verbose:
1430
+ print(rho_msg % (1, low, high_))
1431
+ c = pollard_rho(n, retries=1, max_steps=low, seed=high_)
1432
+ if c:
1433
+ if c < next_p**2 or isprime(c):
1434
+ ps = [c]
1435
+ else:
1436
+ ps = factorint(c, limit=limit,
1437
+ use_trial=use_trial,
1438
+ use_rho=use_rho,
1439
+ use_pm1=use_pm1,
1440
+ use_ecm=use_ecm,
1441
+ verbose=verbose)
1442
+ n, _ = _trial(factors, n, ps, verbose=False)
1443
+ if _check_termination(factors, n, limit, use_trial,
1444
+ use_rho, use_pm1, verbose, next_p):
1445
+ return factors
1446
+ # Use subexponential algorithms if use_ecm
1447
+ # Use pollard algorithms for finding small factors for 3 iterations
1448
+ # if after small factors the number of digits of n >= 25 then use ecm
1449
+ iteration += 1
1450
+ if use_ecm and iteration >= 3 and num_digits(n) >= 24:
1451
+ break
1452
+ low, high = high, high*2
1453
+
1454
+ B1 = 10000
1455
+ B2 = 100*B1
1456
+ num_curves = 50
1457
+ while(1):
1458
+ if verbose:
1459
+ print(ecm_msg % (B1, B2, num_curves))
1460
+ factor = _ecm_one_factor(n, B1, B2, num_curves, seed=B1)
1461
+ if factor:
1462
+ if factor < next_p**2 or isprime(factor):
1463
+ ps = [factor]
1464
+ else:
1465
+ ps = factorint(factor, limit=limit,
1466
+ use_trial=use_trial,
1467
+ use_rho=use_rho,
1468
+ use_pm1=use_pm1,
1469
+ use_ecm=use_ecm,
1470
+ verbose=verbose)
1471
+ n, _ = _trial(factors, n, ps, verbose=False)
1472
+ if _check_termination(factors, n, limit, use_trial,
1473
+ use_rho, use_pm1, verbose, next_p):
1474
+ return factors
1475
+ B1 *= 5
1476
+ B2 = 100*B1
1477
+ num_curves *= 4
1478
+
1479
+
1480
+ def factorrat(rat, limit=None, use_trial=True, use_rho=True, use_pm1=True,
1481
+ verbose=False, visual=None, multiple=False):
1482
+ r"""
1483
+ Given a Rational ``r``, ``factorrat(r)`` returns a dict containing
1484
+ the prime factors of ``r`` as keys and their respective multiplicities
1485
+ as values. For example:
1486
+
1487
+ >>> from sympy import factorrat, S
1488
+ >>> factorrat(S(8)/9) # 8/9 = (2**3) * (3**-2)
1489
+ {2: 3, 3: -2}
1490
+ >>> factorrat(S(-1)/987) # -1/789 = -1 * (3**-1) * (7**-1) * (47**-1)
1491
+ {-1: 1, 3: -1, 7: -1, 47: -1}
1492
+
1493
+ Please see the docstring for ``factorint`` for detailed explanations
1494
+ and examples of the following keywords:
1495
+
1496
+ - ``limit``: Integer limit up to which trial division is done
1497
+ - ``use_trial``: Toggle use of trial division
1498
+ - ``use_rho``: Toggle use of Pollard's rho method
1499
+ - ``use_pm1``: Toggle use of Pollard's p-1 method
1500
+ - ``verbose``: Toggle detailed printing of progress
1501
+ - ``multiple``: Toggle returning a list of factors or dict
1502
+ - ``visual``: Toggle product form of output
1503
+ """
1504
+ if multiple:
1505
+ fac = factorrat(rat, limit=limit, use_trial=use_trial,
1506
+ use_rho=use_rho, use_pm1=use_pm1,
1507
+ verbose=verbose, visual=False, multiple=False)
1508
+ factorlist = sum(([p] * fac[p] if fac[p] > 0 else [S.One/p]*(-fac[p])
1509
+ for p, _ in sorted(fac.items(),
1510
+ key=lambda elem: elem[0]
1511
+ if elem[1] > 0
1512
+ else 1/elem[0])), [])
1513
+ return factorlist
1514
+
1515
+ f = factorint(rat.p, limit=limit, use_trial=use_trial,
1516
+ use_rho=use_rho, use_pm1=use_pm1,
1517
+ verbose=verbose).copy()
1518
+ f = defaultdict(int, f)
1519
+ for p, e in factorint(rat.q, limit=limit,
1520
+ use_trial=use_trial,
1521
+ use_rho=use_rho,
1522
+ use_pm1=use_pm1,
1523
+ verbose=verbose).items():
1524
+ f[p] += -e
1525
+
1526
+ if len(f) > 1 and 1 in f:
1527
+ del f[1]
1528
+ if not visual:
1529
+ return dict(f)
1530
+ else:
1531
+ if -1 in f:
1532
+ f.pop(-1)
1533
+ args = [S.NegativeOne]
1534
+ else:
1535
+ args = []
1536
+ args.extend([Pow(*i, evaluate=False)
1537
+ for i in sorted(f.items())])
1538
+ return Mul(*args, evaluate=False)
1539
+
1540
+
1541
+ def primefactors(n, limit=None, verbose=False, **kwargs):
1542
+ """Return a sorted list of n's prime factors, ignoring multiplicity
1543
+ and any composite factor that remains if the limit was set too low
1544
+ for complete factorization. Unlike factorint(), primefactors() does
1545
+ not return -1 or 0.
1546
+
1547
+ Parameters
1548
+ ==========
1549
+
1550
+ n : integer
1551
+ limit, verbose, **kwargs :
1552
+ Additional keyword arguments to be passed to ``factorint``.
1553
+ Since ``kwargs`` is new in version 1.13,
1554
+ ``limit`` and ``verbose`` are retained for compatibility purposes.
1555
+
1556
+ Returns
1557
+ =======
1558
+
1559
+ list(int) : List of prime numbers dividing ``n``
1560
+
1561
+ Examples
1562
+ ========
1563
+
1564
+ >>> from sympy.ntheory import primefactors, factorint, isprime
1565
+ >>> primefactors(6)
1566
+ [2, 3]
1567
+ >>> primefactors(-5)
1568
+ [5]
1569
+
1570
+ >>> sorted(factorint(123456).items())
1571
+ [(2, 6), (3, 1), (643, 1)]
1572
+ >>> primefactors(123456)
1573
+ [2, 3, 643]
1574
+
1575
+ >>> sorted(factorint(10000000001, limit=200).items())
1576
+ [(101, 1), (99009901, 1)]
1577
+ >>> isprime(99009901)
1578
+ False
1579
+ >>> primefactors(10000000001, limit=300)
1580
+ [101]
1581
+
1582
+ See Also
1583
+ ========
1584
+
1585
+ factorint, divisors
1586
+
1587
+ """
1588
+ n = int(n)
1589
+ kwargs.update({"visual": None, "multiple": False,
1590
+ "limit": limit, "verbose": verbose})
1591
+ factors = sorted(factorint(n=n, **kwargs).keys())
1592
+ # We want to calculate
1593
+ # s = [f for f in factors if isprime(f)]
1594
+ s = [f for f in factors[:-1:] if f not in [-1, 0, 1]]
1595
+ if factors and isprime(factors[-1]):
1596
+ s += [factors[-1]]
1597
+ return s
1598
+
1599
+
1600
+ def _divisors(n, proper=False):
1601
+ """Helper function for divisors which generates the divisors.
1602
+
1603
+ Parameters
1604
+ ==========
1605
+
1606
+ n : int
1607
+ a nonnegative integer
1608
+ proper: bool
1609
+ If `True`, returns the generator that outputs only the proper divisor (i.e., excluding n).
1610
+
1611
+ """
1612
+ if n <= 1:
1613
+ if not proper and n:
1614
+ yield 1
1615
+ return
1616
+
1617
+ factordict = factorint(n)
1618
+ ps = sorted(factordict.keys())
1619
+
1620
+ def rec_gen(n=0):
1621
+ if n == len(ps):
1622
+ yield 1
1623
+ else:
1624
+ pows = [1]
1625
+ for _ in range(factordict[ps[n]]):
1626
+ pows.append(pows[-1] * ps[n])
1627
+ yield from (p * q for q in rec_gen(n + 1) for p in pows)
1628
+
1629
+ if proper:
1630
+ yield from (p for p in rec_gen() if p != n)
1631
+ else:
1632
+ yield from rec_gen()
1633
+
1634
+
1635
+ def divisors(n, generator=False, proper=False):
1636
+ r"""
1637
+ Return all divisors of n sorted from 1..n by default.
1638
+ If generator is ``True`` an unordered generator is returned.
1639
+
1640
+ The number of divisors of n can be quite large if there are many
1641
+ prime factors (counting repeated factors). If only the number of
1642
+ factors is desired use divisor_count(n).
1643
+
1644
+ Examples
1645
+ ========
1646
+
1647
+ >>> from sympy import divisors, divisor_count
1648
+ >>> divisors(24)
1649
+ [1, 2, 3, 4, 6, 8, 12, 24]
1650
+ >>> divisor_count(24)
1651
+ 8
1652
+
1653
+ >>> list(divisors(120, generator=True))
1654
+ [1, 2, 4, 8, 3, 6, 12, 24, 5, 10, 20, 40, 15, 30, 60, 120]
1655
+
1656
+ Notes
1657
+ =====
1658
+
1659
+ This is a slightly modified version of Tim Peters referenced at:
1660
+ https://stackoverflow.com/questions/1010381/python-factorization
1661
+
1662
+ See Also
1663
+ ========
1664
+
1665
+ primefactors, factorint, divisor_count
1666
+ """
1667
+ rv = _divisors(as_int(abs(n)), proper)
1668
+ return rv if generator else sorted(rv)
1669
+
1670
+
1671
+ def divisor_count(n, modulus=1, proper=False):
1672
+ """
1673
+ Return the number of divisors of ``n``. If ``modulus`` is not 1 then only
1674
+ those that are divisible by ``modulus`` are counted. If ``proper`` is True
1675
+ then the divisor of ``n`` will not be counted.
1676
+
1677
+ Examples
1678
+ ========
1679
+
1680
+ >>> from sympy import divisor_count
1681
+ >>> divisor_count(6)
1682
+ 4
1683
+ >>> divisor_count(6, 2)
1684
+ 2
1685
+ >>> divisor_count(6, proper=True)
1686
+ 3
1687
+
1688
+ See Also
1689
+ ========
1690
+
1691
+ factorint, divisors, totient, proper_divisor_count
1692
+
1693
+ """
1694
+
1695
+ if not modulus:
1696
+ return 0
1697
+ elif modulus != 1:
1698
+ n, r = divmod(n, modulus)
1699
+ if r:
1700
+ return 0
1701
+ if n == 0:
1702
+ return 0
1703
+ n = Mul(*[v + 1 for k, v in factorint(n).items() if k > 1])
1704
+ if n and proper:
1705
+ n -= 1
1706
+ return n
1707
+
1708
+
1709
+ def proper_divisors(n, generator=False):
1710
+ """
1711
+ Return all divisors of n except n, sorted by default.
1712
+ If generator is ``True`` an unordered generator is returned.
1713
+
1714
+ Examples
1715
+ ========
1716
+
1717
+ >>> from sympy import proper_divisors, proper_divisor_count
1718
+ >>> proper_divisors(24)
1719
+ [1, 2, 3, 4, 6, 8, 12]
1720
+ >>> proper_divisor_count(24)
1721
+ 7
1722
+ >>> list(proper_divisors(120, generator=True))
1723
+ [1, 2, 4, 8, 3, 6, 12, 24, 5, 10, 20, 40, 15, 30, 60]
1724
+
1725
+ See Also
1726
+ ========
1727
+
1728
+ factorint, divisors, proper_divisor_count
1729
+
1730
+ """
1731
+ return divisors(n, generator=generator, proper=True)
1732
+
1733
+
1734
+ def proper_divisor_count(n, modulus=1):
1735
+ """
1736
+ Return the number of proper divisors of ``n``.
1737
+
1738
+ Examples
1739
+ ========
1740
+
1741
+ >>> from sympy import proper_divisor_count
1742
+ >>> proper_divisor_count(6)
1743
+ 3
1744
+ >>> proper_divisor_count(6, modulus=2)
1745
+ 1
1746
+
1747
+ See Also
1748
+ ========
1749
+
1750
+ divisors, proper_divisors, divisor_count
1751
+
1752
+ """
1753
+ return divisor_count(n, modulus=modulus, proper=True)
1754
+
1755
+
1756
+ def _udivisors(n):
1757
+ """Helper function for udivisors which generates the unitary divisors.
1758
+
1759
+ Parameters
1760
+ ==========
1761
+
1762
+ n : int
1763
+ a nonnegative integer
1764
+
1765
+ """
1766
+ if n <= 1:
1767
+ if n == 1:
1768
+ yield 1
1769
+ return
1770
+
1771
+ factorpows = [p**e for p, e in factorint(n).items()]
1772
+ # We want to calculate
1773
+ # yield from (math.prod(s) for s in powersets(factorpows))
1774
+ for i in range(2**len(factorpows)):
1775
+ d = 1
1776
+ for k in range(i.bit_length()):
1777
+ if i & 1:
1778
+ d *= factorpows[k]
1779
+ i >>= 1
1780
+ yield d
1781
+
1782
+
1783
+ def udivisors(n, generator=False):
1784
+ r"""
1785
+ Return all unitary divisors of n sorted from 1..n by default.
1786
+ If generator is ``True`` an unordered generator is returned.
1787
+
1788
+ The number of unitary divisors of n can be quite large if there are many
1789
+ prime factors. If only the number of unitary divisors is desired use
1790
+ udivisor_count(n).
1791
+
1792
+ Examples
1793
+ ========
1794
+
1795
+ >>> from sympy.ntheory.factor_ import udivisors, udivisor_count
1796
+ >>> udivisors(15)
1797
+ [1, 3, 5, 15]
1798
+ >>> udivisor_count(15)
1799
+ 4
1800
+
1801
+ >>> sorted(udivisors(120, generator=True))
1802
+ [1, 3, 5, 8, 15, 24, 40, 120]
1803
+
1804
+ See Also
1805
+ ========
1806
+
1807
+ primefactors, factorint, divisors, divisor_count, udivisor_count
1808
+
1809
+ References
1810
+ ==========
1811
+
1812
+ .. [1] https://en.wikipedia.org/wiki/Unitary_divisor
1813
+ .. [2] https://mathworld.wolfram.com/UnitaryDivisor.html
1814
+
1815
+ """
1816
+ rv = _udivisors(as_int(abs(n)))
1817
+ return rv if generator else sorted(rv)
1818
+
1819
+
1820
+ def udivisor_count(n):
1821
+ """
1822
+ Return the number of unitary divisors of ``n``.
1823
+
1824
+ Parameters
1825
+ ==========
1826
+
1827
+ n : integer
1828
+
1829
+ Examples
1830
+ ========
1831
+
1832
+ >>> from sympy.ntheory.factor_ import udivisor_count
1833
+ >>> udivisor_count(120)
1834
+ 8
1835
+
1836
+ See Also
1837
+ ========
1838
+
1839
+ factorint, divisors, udivisors, divisor_count, totient
1840
+
1841
+ References
1842
+ ==========
1843
+
1844
+ .. [1] https://mathworld.wolfram.com/UnitaryDivisorFunction.html
1845
+
1846
+ """
1847
+
1848
+ if n == 0:
1849
+ return 0
1850
+ return 2**len([p for p in factorint(n) if p > 1])
1851
+
1852
+
1853
+ def _antidivisors(n):
1854
+ """Helper function for antidivisors which generates the antidivisors.
1855
+
1856
+ Parameters
1857
+ ==========
1858
+
1859
+ n : int
1860
+ a nonnegative integer
1861
+
1862
+ """
1863
+ if n <= 2:
1864
+ return
1865
+ for d in _divisors(n):
1866
+ y = 2*d
1867
+ if n > y and n % y:
1868
+ yield y
1869
+ for d in _divisors(2*n-1):
1870
+ if n > d >= 2 and n % d:
1871
+ yield d
1872
+ for d in _divisors(2*n+1):
1873
+ if n > d >= 2 and n % d:
1874
+ yield d
1875
+
1876
+
1877
+ def antidivisors(n, generator=False):
1878
+ r"""
1879
+ Return all antidivisors of n sorted from 1..n by default.
1880
+
1881
+ Antidivisors [1]_ of n are numbers that do not divide n by the largest
1882
+ possible margin. If generator is True an unordered generator is returned.
1883
+
1884
+ Examples
1885
+ ========
1886
+
1887
+ >>> from sympy.ntheory.factor_ import antidivisors
1888
+ >>> antidivisors(24)
1889
+ [7, 16]
1890
+
1891
+ >>> sorted(antidivisors(128, generator=True))
1892
+ [3, 5, 15, 17, 51, 85]
1893
+
1894
+ See Also
1895
+ ========
1896
+
1897
+ primefactors, factorint, divisors, divisor_count, antidivisor_count
1898
+
1899
+ References
1900
+ ==========
1901
+
1902
+ .. [1] definition is described in https://oeis.org/A066272/a066272a.html
1903
+
1904
+ """
1905
+ rv = _antidivisors(as_int(abs(n)))
1906
+ return rv if generator else sorted(rv)
1907
+
1908
+
1909
+ def antidivisor_count(n):
1910
+ """
1911
+ Return the number of antidivisors [1]_ of ``n``.
1912
+
1913
+ Parameters
1914
+ ==========
1915
+
1916
+ n : integer
1917
+
1918
+ Examples
1919
+ ========
1920
+
1921
+ >>> from sympy.ntheory.factor_ import antidivisor_count
1922
+ >>> antidivisor_count(13)
1923
+ 4
1924
+ >>> antidivisor_count(27)
1925
+ 5
1926
+
1927
+ See Also
1928
+ ========
1929
+
1930
+ factorint, divisors, antidivisors, divisor_count, totient
1931
+
1932
+ References
1933
+ ==========
1934
+
1935
+ .. [1] formula from https://oeis.org/A066272
1936
+
1937
+ """
1938
+
1939
+ n = as_int(abs(n))
1940
+ if n <= 2:
1941
+ return 0
1942
+ return divisor_count(2*n - 1) + divisor_count(2*n + 1) + \
1943
+ divisor_count(n) - divisor_count(n, 2) - 5
1944
+
1945
+ @deprecated("""\
1946
+ The `sympy.ntheory.factor_.totient` has been moved to `sympy.functions.combinatorial.numbers.totient`.""",
1947
+ deprecated_since_version="1.13",
1948
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
1949
+ def totient(n):
1950
+ r"""
1951
+ Calculate the Euler totient function phi(n)
1952
+
1953
+ .. deprecated:: 1.13
1954
+
1955
+ The ``totient`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.totient`
1956
+ instead. See its documentation for more information. See
1957
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
1958
+
1959
+ ``totient(n)`` or `\phi(n)` is the number of positive integers `\leq` n
1960
+ that are relatively prime to n.
1961
+
1962
+ Parameters
1963
+ ==========
1964
+
1965
+ n : integer
1966
+
1967
+ Examples
1968
+ ========
1969
+
1970
+ >>> from sympy.functions.combinatorial.numbers import totient
1971
+ >>> totient(1)
1972
+ 1
1973
+ >>> totient(25)
1974
+ 20
1975
+ >>> totient(45) == totient(5)*totient(9)
1976
+ True
1977
+
1978
+ See Also
1979
+ ========
1980
+
1981
+ divisor_count
1982
+
1983
+ References
1984
+ ==========
1985
+
1986
+ .. [1] https://en.wikipedia.org/wiki/Euler%27s_totient_function
1987
+ .. [2] https://mathworld.wolfram.com/TotientFunction.html
1988
+
1989
+ """
1990
+ from sympy.functions.combinatorial.numbers import totient as _totient
1991
+ return _totient(n)
1992
+
1993
+
1994
+ @deprecated("""\
1995
+ The `sympy.ntheory.factor_.reduced_totient` has been moved to `sympy.functions.combinatorial.numbers.reduced_totient`.""",
1996
+ deprecated_since_version="1.13",
1997
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
1998
+ def reduced_totient(n):
1999
+ r"""
2000
+ Calculate the Carmichael reduced totient function lambda(n)
2001
+
2002
+ .. deprecated:: 1.13
2003
+
2004
+ The ``reduced_totient`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.reduced_totient`
2005
+ instead. See its documentation for more information. See
2006
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
2007
+
2008
+ ``reduced_totient(n)`` or `\lambda(n)` is the smallest m > 0 such that
2009
+ `k^m \equiv 1 \mod n` for all k relatively prime to n.
2010
+
2011
+ Examples
2012
+ ========
2013
+
2014
+ >>> from sympy.functions.combinatorial.numbers import reduced_totient
2015
+ >>> reduced_totient(1)
2016
+ 1
2017
+ >>> reduced_totient(8)
2018
+ 2
2019
+ >>> reduced_totient(30)
2020
+ 4
2021
+
2022
+ See Also
2023
+ ========
2024
+
2025
+ totient
2026
+
2027
+ References
2028
+ ==========
2029
+
2030
+ .. [1] https://en.wikipedia.org/wiki/Carmichael_function
2031
+ .. [2] https://mathworld.wolfram.com/CarmichaelFunction.html
2032
+
2033
+ """
2034
+ from sympy.functions.combinatorial.numbers import reduced_totient as _reduced_totient
2035
+ return _reduced_totient(n)
2036
+
2037
+
2038
+ @deprecated("""\
2039
+ The `sympy.ntheory.factor_.divisor_sigma` has been moved to `sympy.functions.combinatorial.numbers.divisor_sigma`.""",
2040
+ deprecated_since_version="1.13",
2041
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
2042
+ def divisor_sigma(n, k=1):
2043
+ r"""
2044
+ Calculate the divisor function `\sigma_k(n)` for positive integer n
2045
+
2046
+ .. deprecated:: 1.13
2047
+
2048
+ The ``divisor_sigma`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.divisor_sigma`
2049
+ instead. See its documentation for more information. See
2050
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
2051
+
2052
+ ``divisor_sigma(n, k)`` is equal to ``sum([x**k for x in divisors(n)])``
2053
+
2054
+ If n's prime factorization is:
2055
+
2056
+ .. math ::
2057
+ n = \prod_{i=1}^\omega p_i^{m_i},
2058
+
2059
+ then
2060
+
2061
+ .. math ::
2062
+ \sigma_k(n) = \prod_{i=1}^\omega (1+p_i^k+p_i^{2k}+\cdots
2063
+ + p_i^{m_ik}).
2064
+
2065
+ Parameters
2066
+ ==========
2067
+
2068
+ n : integer
2069
+
2070
+ k : integer, optional
2071
+ power of divisors in the sum
2072
+
2073
+ for k = 0, 1:
2074
+ ``divisor_sigma(n, 0)`` is equal to ``divisor_count(n)``
2075
+ ``divisor_sigma(n, 1)`` is equal to ``sum(divisors(n))``
2076
+
2077
+ Default for k is 1.
2078
+
2079
+ Examples
2080
+ ========
2081
+
2082
+ >>> from sympy.functions.combinatorial.numbers import divisor_sigma
2083
+ >>> divisor_sigma(18, 0)
2084
+ 6
2085
+ >>> divisor_sigma(39, 1)
2086
+ 56
2087
+ >>> divisor_sigma(12, 2)
2088
+ 210
2089
+ >>> divisor_sigma(37)
2090
+ 38
2091
+
2092
+ See Also
2093
+ ========
2094
+
2095
+ divisor_count, totient, divisors, factorint
2096
+
2097
+ References
2098
+ ==========
2099
+
2100
+ .. [1] https://en.wikipedia.org/wiki/Divisor_function
2101
+
2102
+ """
2103
+ from sympy.functions.combinatorial.numbers import divisor_sigma as func_divisor_sigma
2104
+ return func_divisor_sigma(n, k)
2105
+
2106
+
2107
+ def _divisor_sigma(n:int, k:int=1) -> int:
2108
+ r""" Calculate the divisor function `\sigma_k(n)` for positive integer n
2109
+
2110
+ Parameters
2111
+ ==========
2112
+
2113
+ n : int
2114
+ positive integer
2115
+ k : int
2116
+ nonnegative integer
2117
+
2118
+ See Also
2119
+ ========
2120
+
2121
+ sympy.functions.combinatorial.numbers.divisor_sigma
2122
+
2123
+ """
2124
+ if k == 0:
2125
+ return math.prod(e + 1 for e in factorint(n).values())
2126
+ return math.prod((p**(k*(e + 1)) - 1)//(p**k - 1) for p, e in factorint(n).items())
2127
+
2128
+
2129
+ def core(n, t=2):
2130
+ r"""
2131
+ Calculate core(n, t) = `core_t(n)` of a positive integer n
2132
+
2133
+ ``core_2(n)`` is equal to the squarefree part of n
2134
+
2135
+ If n's prime factorization is:
2136
+
2137
+ .. math ::
2138
+ n = \prod_{i=1}^\omega p_i^{m_i},
2139
+
2140
+ then
2141
+
2142
+ .. math ::
2143
+ core_t(n) = \prod_{i=1}^\omega p_i^{m_i \mod t}.
2144
+
2145
+ Parameters
2146
+ ==========
2147
+
2148
+ n : integer
2149
+
2150
+ t : integer
2151
+ core(n, t) calculates the t-th power free part of n
2152
+
2153
+ ``core(n, 2)`` is the squarefree part of ``n``
2154
+ ``core(n, 3)`` is the cubefree part of ``n``
2155
+
2156
+ Default for t is 2.
2157
+
2158
+ Examples
2159
+ ========
2160
+
2161
+ >>> from sympy.ntheory.factor_ import core
2162
+ >>> core(24, 2)
2163
+ 6
2164
+ >>> core(9424, 3)
2165
+ 1178
2166
+ >>> core(379238)
2167
+ 379238
2168
+ >>> core(15**11, 10)
2169
+ 15
2170
+
2171
+ See Also
2172
+ ========
2173
+
2174
+ factorint, sympy.solvers.diophantine.diophantine.square_factor
2175
+
2176
+ References
2177
+ ==========
2178
+
2179
+ .. [1] https://en.wikipedia.org/wiki/Square-free_integer#Squarefree_core
2180
+
2181
+ """
2182
+
2183
+ n = as_int(n)
2184
+ t = as_int(t)
2185
+ if n <= 0:
2186
+ raise ValueError("n must be a positive integer")
2187
+ elif t <= 1:
2188
+ raise ValueError("t must be >= 2")
2189
+ else:
2190
+ y = 1
2191
+ for p, e in factorint(n).items():
2192
+ y *= p**(e % t)
2193
+ return y
2194
+
2195
+
2196
+ @deprecated("""\
2197
+ The `sympy.ntheory.factor_.udivisor_sigma` has been moved to `sympy.functions.combinatorial.numbers.udivisor_sigma`.""",
2198
+ deprecated_since_version="1.13",
2199
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
2200
+ def udivisor_sigma(n, k=1):
2201
+ r"""
2202
+ Calculate the unitary divisor function `\sigma_k^*(n)` for positive integer n
2203
+
2204
+ .. deprecated:: 1.13
2205
+
2206
+ The ``udivisor_sigma`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.udivisor_sigma`
2207
+ instead. See its documentation for more information. See
2208
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
2209
+
2210
+ ``udivisor_sigma(n, k)`` is equal to ``sum([x**k for x in udivisors(n)])``
2211
+
2212
+ If n's prime factorization is:
2213
+
2214
+ .. math ::
2215
+ n = \prod_{i=1}^\omega p_i^{m_i},
2216
+
2217
+ then
2218
+
2219
+ .. math ::
2220
+ \sigma_k^*(n) = \prod_{i=1}^\omega (1+ p_i^{m_ik}).
2221
+
2222
+ Parameters
2223
+ ==========
2224
+
2225
+ k : power of divisors in the sum
2226
+
2227
+ for k = 0, 1:
2228
+ ``udivisor_sigma(n, 0)`` is equal to ``udivisor_count(n)``
2229
+ ``udivisor_sigma(n, 1)`` is equal to ``sum(udivisors(n))``
2230
+
2231
+ Default for k is 1.
2232
+
2233
+ Examples
2234
+ ========
2235
+
2236
+ >>> from sympy.functions.combinatorial.numbers import udivisor_sigma
2237
+ >>> udivisor_sigma(18, 0)
2238
+ 4
2239
+ >>> udivisor_sigma(74, 1)
2240
+ 114
2241
+ >>> udivisor_sigma(36, 3)
2242
+ 47450
2243
+ >>> udivisor_sigma(111)
2244
+ 152
2245
+
2246
+ See Also
2247
+ ========
2248
+
2249
+ divisor_count, totient, divisors, udivisors, udivisor_count, divisor_sigma,
2250
+ factorint
2251
+
2252
+ References
2253
+ ==========
2254
+
2255
+ .. [1] https://mathworld.wolfram.com/UnitaryDivisorFunction.html
2256
+
2257
+ """
2258
+ from sympy.functions.combinatorial.numbers import udivisor_sigma as _udivisor_sigma
2259
+ return _udivisor_sigma(n, k)
2260
+
2261
+
2262
+ @deprecated("""\
2263
+ The `sympy.ntheory.factor_.primenu` has been moved to `sympy.functions.combinatorial.numbers.primenu`.""",
2264
+ deprecated_since_version="1.13",
2265
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
2266
+ def primenu(n):
2267
+ r"""
2268
+ Calculate the number of distinct prime factors for a positive integer n.
2269
+
2270
+ .. deprecated:: 1.13
2271
+
2272
+ The ``primenu`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.primenu`
2273
+ instead. See its documentation for more information. See
2274
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
2275
+
2276
+ If n's prime factorization is:
2277
+
2278
+ .. math ::
2279
+ n = \prod_{i=1}^k p_i^{m_i},
2280
+
2281
+ then ``primenu(n)`` or `\nu(n)` is:
2282
+
2283
+ .. math ::
2284
+ \nu(n) = k.
2285
+
2286
+ Examples
2287
+ ========
2288
+
2289
+ >>> from sympy.functions.combinatorial.numbers import primenu
2290
+ >>> primenu(1)
2291
+ 0
2292
+ >>> primenu(30)
2293
+ 3
2294
+
2295
+ See Also
2296
+ ========
2297
+
2298
+ factorint
2299
+
2300
+ References
2301
+ ==========
2302
+
2303
+ .. [1] https://mathworld.wolfram.com/PrimeFactor.html
2304
+
2305
+ """
2306
+ from sympy.functions.combinatorial.numbers import primenu as _primenu
2307
+ return _primenu(n)
2308
+
2309
+
2310
+ @deprecated("""\
2311
+ The `sympy.ntheory.factor_.primeomega` has been moved to `sympy.functions.combinatorial.numbers.primeomega`.""",
2312
+ deprecated_since_version="1.13",
2313
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
2314
+ def primeomega(n):
2315
+ r"""
2316
+ Calculate the number of prime factors counting multiplicities for a
2317
+ positive integer n.
2318
+
2319
+ .. deprecated:: 1.13
2320
+
2321
+ The ``primeomega`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.primeomega`
2322
+ instead. See its documentation for more information. See
2323
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
2324
+
2325
+ If n's prime factorization is:
2326
+
2327
+ .. math ::
2328
+ n = \prod_{i=1}^k p_i^{m_i},
2329
+
2330
+ then ``primeomega(n)`` or `\Omega(n)` is:
2331
+
2332
+ .. math ::
2333
+ \Omega(n) = \sum_{i=1}^k m_i.
2334
+
2335
+ Examples
2336
+ ========
2337
+
2338
+ >>> from sympy.functions.combinatorial.numbers import primeomega
2339
+ >>> primeomega(1)
2340
+ 0
2341
+ >>> primeomega(20)
2342
+ 3
2343
+
2344
+ See Also
2345
+ ========
2346
+
2347
+ factorint
2348
+
2349
+ References
2350
+ ==========
2351
+
2352
+ .. [1] https://mathworld.wolfram.com/PrimeFactor.html
2353
+
2354
+ """
2355
+ from sympy.functions.combinatorial.numbers import primeomega as _primeomega
2356
+ return _primeomega(n)
2357
+
2358
+
2359
+ def mersenne_prime_exponent(nth):
2360
+ """Returns the exponent ``i`` for the nth Mersenne prime (which
2361
+ has the form `2^i - 1`).
2362
+
2363
+ Examples
2364
+ ========
2365
+
2366
+ >>> from sympy.ntheory.factor_ import mersenne_prime_exponent
2367
+ >>> mersenne_prime_exponent(1)
2368
+ 2
2369
+ >>> mersenne_prime_exponent(20)
2370
+ 4423
2371
+ """
2372
+ n = as_int(nth)
2373
+ if n < 1:
2374
+ raise ValueError("nth must be a positive integer; mersenne_prime_exponent(1) == 2")
2375
+ if n > 51:
2376
+ raise ValueError("There are only 51 perfect numbers; nth must be less than or equal to 51")
2377
+ return MERSENNE_PRIME_EXPONENTS[n - 1]
2378
+
2379
+
2380
+ def is_perfect(n):
2381
+ """Returns True if ``n`` is a perfect number, else False.
2382
+
2383
+ A perfect number is equal to the sum of its positive, proper divisors.
2384
+
2385
+ Examples
2386
+ ========
2387
+
2388
+ >>> from sympy.functions.combinatorial.numbers import divisor_sigma
2389
+ >>> from sympy.ntheory.factor_ import is_perfect, divisors
2390
+ >>> is_perfect(20)
2391
+ False
2392
+ >>> is_perfect(6)
2393
+ True
2394
+ >>> 6 == divisor_sigma(6) - 6 == sum(divisors(6)[:-1])
2395
+ True
2396
+
2397
+ References
2398
+ ==========
2399
+
2400
+ .. [1] https://mathworld.wolfram.com/PerfectNumber.html
2401
+ .. [2] https://en.wikipedia.org/wiki/Perfect_number
2402
+
2403
+ """
2404
+ n = as_int(n)
2405
+ if n < 1:
2406
+ return False
2407
+ if n % 2 == 0:
2408
+ m = (n.bit_length() + 1) >> 1
2409
+ if (1 << (m - 1)) * ((1 << m) - 1) != n:
2410
+ # Even perfect numbers must be of the form `2^{m-1}(2^m-1)`
2411
+ return False
2412
+ return m in MERSENNE_PRIME_EXPONENTS or is_mersenne_prime(2**m - 1)
2413
+
2414
+ # n is an odd integer
2415
+ if n < 10**2000: # https://www.lirmm.fr/~ochem/opn/
2416
+ return False
2417
+ if n % 105 == 0: # not divis by 105
2418
+ return False
2419
+ if all(n % m != r for m, r in [(12, 1), (468, 117), (324, 81)]):
2420
+ return False
2421
+ # there are many criteria that the factor structure of n
2422
+ # must meet; since we will have to factor it to test the
2423
+ # structure we will have the factors and can then check
2424
+ # to see whether it is a perfect number or not. So we
2425
+ # skip the structure checks and go straight to the final
2426
+ # test below.
2427
+ result = abundance(n) == 0
2428
+ if result:
2429
+ raise ValueError(filldedent('''In 1888, Sylvester stated: "
2430
+ ...a prolonged meditation on the subject has satisfied
2431
+ me that the existence of any one such [odd perfect number]
2432
+ -- its escape, so to say, from the complex web of conditions
2433
+ which hem it in on all sides -- would be little short of a
2434
+ miracle." I guess SymPy just found that miracle and it
2435
+ factors like this: %s''' % factorint(n)))
2436
+ return result
2437
+
2438
+
2439
+ def abundance(n):
2440
+ """Returns the difference between the sum of the positive
2441
+ proper divisors of a number and the number.
2442
+
2443
+ Examples
2444
+ ========
2445
+
2446
+ >>> from sympy.ntheory import abundance, is_perfect, is_abundant
2447
+ >>> abundance(6)
2448
+ 0
2449
+ >>> is_perfect(6)
2450
+ True
2451
+ >>> abundance(10)
2452
+ -2
2453
+ >>> is_abundant(10)
2454
+ False
2455
+ """
2456
+ return _divisor_sigma(n) - 2 * n
2457
+
2458
+
2459
+ def is_abundant(n):
2460
+ """Returns True if ``n`` is an abundant number, else False.
2461
+
2462
+ A abundant number is smaller than the sum of its positive proper divisors.
2463
+
2464
+ Examples
2465
+ ========
2466
+
2467
+ >>> from sympy.ntheory.factor_ import is_abundant
2468
+ >>> is_abundant(20)
2469
+ True
2470
+ >>> is_abundant(15)
2471
+ False
2472
+
2473
+ References
2474
+ ==========
2475
+
2476
+ .. [1] https://mathworld.wolfram.com/AbundantNumber.html
2477
+
2478
+ """
2479
+ n = as_int(n)
2480
+ if is_perfect(n):
2481
+ return False
2482
+ return n % 6 == 0 or bool(abundance(n) > 0)
2483
+
2484
+
2485
+ def is_deficient(n):
2486
+ """Returns True if ``n`` is a deficient number, else False.
2487
+
2488
+ A deficient number is greater than the sum of its positive proper divisors.
2489
+
2490
+ Examples
2491
+ ========
2492
+
2493
+ >>> from sympy.ntheory.factor_ import is_deficient
2494
+ >>> is_deficient(20)
2495
+ False
2496
+ >>> is_deficient(15)
2497
+ True
2498
+
2499
+ References
2500
+ ==========
2501
+
2502
+ .. [1] https://mathworld.wolfram.com/DeficientNumber.html
2503
+
2504
+ """
2505
+ n = as_int(n)
2506
+ if is_perfect(n):
2507
+ return False
2508
+ return bool(abundance(n) < 0)
2509
+
2510
+
2511
+ def is_amicable(m, n):
2512
+ """Returns True if the numbers `m` and `n` are "amicable", else False.
2513
+
2514
+ Amicable numbers are two different numbers so related that the sum
2515
+ of the proper divisors of each is equal to that of the other.
2516
+
2517
+ Examples
2518
+ ========
2519
+
2520
+ >>> from sympy.functions.combinatorial.numbers import divisor_sigma
2521
+ >>> from sympy.ntheory.factor_ import is_amicable
2522
+ >>> is_amicable(220, 284)
2523
+ True
2524
+ >>> divisor_sigma(220) == divisor_sigma(284)
2525
+ True
2526
+
2527
+ References
2528
+ ==========
2529
+
2530
+ .. [1] https://en.wikipedia.org/wiki/Amicable_numbers
2531
+
2532
+ """
2533
+ return m != n and m + n == _divisor_sigma(m) == _divisor_sigma(n)
2534
+
2535
+
2536
+ def is_carmichael(n):
2537
+ """ Returns True if the numbers `n` is Carmichael number, else False.
2538
+
2539
+ Parameters
2540
+ ==========
2541
+
2542
+ n : Integer
2543
+
2544
+ References
2545
+ ==========
2546
+
2547
+ .. [1] https://en.wikipedia.org/wiki/Carmichael_number
2548
+ .. [2] https://oeis.org/A002997
2549
+
2550
+ """
2551
+ if n < 561:
2552
+ return False
2553
+ return n % 2 and not isprime(n) and \
2554
+ all(e == 1 and (n - 1) % (p - 1) == 0 for p, e in factorint(n).items())
2555
+
2556
+
2557
+ def find_carmichael_numbers_in_range(x, y):
2558
+ """ Returns a list of the number of Carmichael in the range
2559
+
2560
+ See Also
2561
+ ========
2562
+
2563
+ is_carmichael
2564
+
2565
+ """
2566
+ if 0 <= x <= y:
2567
+ if x % 2 == 0:
2568
+ return [i for i in range(x + 1, y, 2) if is_carmichael(i)]
2569
+ else:
2570
+ return [i for i in range(x, y, 2) if is_carmichael(i)]
2571
+ else:
2572
+ raise ValueError('The provided range is not valid. x and y must be non-negative integers and x <= y')
2573
+
2574
+
2575
+ def find_first_n_carmichaels(n):
2576
+ """ Returns the first n Carmichael numbers.
2577
+
2578
+ Parameters
2579
+ ==========
2580
+
2581
+ n : Integer
2582
+
2583
+ See Also
2584
+ ========
2585
+
2586
+ is_carmichael
2587
+
2588
+ """
2589
+ i = 561
2590
+ carmichaels = []
2591
+
2592
+ while len(carmichaels) < n:
2593
+ if is_carmichael(i):
2594
+ carmichaels.append(i)
2595
+ i += 2
2596
+
2597
+ return carmichaels
2598
+
2599
+
2600
+ def dra(n, b):
2601
+ """
2602
+ Returns the additive digital root of a natural number ``n`` in base ``b``
2603
+ which is a single digit value obtained by an iterative process of summing
2604
+ digits, on each iteration using the result from the previous iteration to
2605
+ compute a digit sum.
2606
+
2607
+ Examples
2608
+ ========
2609
+
2610
+ >>> from sympy.ntheory.factor_ import dra
2611
+ >>> dra(3110, 12)
2612
+ 8
2613
+
2614
+ References
2615
+ ==========
2616
+
2617
+ .. [1] https://en.wikipedia.org/wiki/Digital_root
2618
+
2619
+ """
2620
+
2621
+ num = abs(as_int(n))
2622
+ b = as_int(b)
2623
+ if b <= 1:
2624
+ raise ValueError("Base should be an integer greater than 1")
2625
+
2626
+ if num == 0:
2627
+ return 0
2628
+
2629
+ return (1 + (num - 1) % (b - 1))
2630
+
2631
+
2632
+ def drm(n, b):
2633
+ """
2634
+ Returns the multiplicative digital root of a natural number ``n`` in a given
2635
+ base ``b`` which is a single digit value obtained by an iterative process of
2636
+ multiplying digits, on each iteration using the result from the previous
2637
+ iteration to compute the digit multiplication.
2638
+
2639
+ Examples
2640
+ ========
2641
+
2642
+ >>> from sympy.ntheory.factor_ import drm
2643
+ >>> drm(9876, 10)
2644
+ 0
2645
+
2646
+ >>> drm(49, 10)
2647
+ 8
2648
+
2649
+ References
2650
+ ==========
2651
+
2652
+ .. [1] https://mathworld.wolfram.com/MultiplicativeDigitalRoot.html
2653
+
2654
+ """
2655
+
2656
+ n = abs(as_int(n))
2657
+ b = as_int(b)
2658
+ if b <= 1:
2659
+ raise ValueError("Base should be an integer greater than 1")
2660
+ while n > b:
2661
+ mul = 1
2662
+ while n > 1:
2663
+ n, r = divmod(n, b)
2664
+ if r == 0:
2665
+ return 0
2666
+ mul *= r
2667
+ n = mul
2668
+ return n
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/modular.py ADDED
@@ -0,0 +1,291 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from math import prod
2
+
3
+ from sympy.external.gmpy import gcd, gcdext
4
+ from sympy.ntheory.primetest import isprime
5
+ from sympy.polys.domains import ZZ
6
+ from sympy.polys.galoistools import gf_crt, gf_crt1, gf_crt2
7
+ from sympy.utilities.misc import as_int
8
+
9
+
10
+ def symmetric_residue(a, m):
11
+ """Return the residual mod m such that it is within half of the modulus.
12
+
13
+ >>> from sympy.ntheory.modular import symmetric_residue
14
+ >>> symmetric_residue(1, 6)
15
+ 1
16
+ >>> symmetric_residue(4, 6)
17
+ -2
18
+ """
19
+ if a <= m // 2:
20
+ return a
21
+ return a - m
22
+
23
+
24
+ def crt(m, v, symmetric=False, check=True):
25
+ r"""Chinese Remainder Theorem.
26
+
27
+ The moduli in m are assumed to be pairwise coprime. The output
28
+ is then an integer f, such that f = v_i mod m_i for each pair out
29
+ of v and m. If ``symmetric`` is False a positive integer will be
30
+ returned, else \|f\| will be less than or equal to the LCM of the
31
+ moduli, and thus f may be negative.
32
+
33
+ If the moduli are not co-prime the correct result will be returned
34
+ if/when the test of the result is found to be incorrect. This result
35
+ will be None if there is no solution.
36
+
37
+ The keyword ``check`` can be set to False if it is known that the moduli
38
+ are coprime.
39
+
40
+ Examples
41
+ ========
42
+
43
+ As an example consider a set of residues ``U = [49, 76, 65]``
44
+ and a set of moduli ``M = [99, 97, 95]``. Then we have::
45
+
46
+ >>> from sympy.ntheory.modular import crt
47
+
48
+ >>> crt([99, 97, 95], [49, 76, 65])
49
+ (639985, 912285)
50
+
51
+ This is the correct result because::
52
+
53
+ >>> [639985 % m for m in [99, 97, 95]]
54
+ [49, 76, 65]
55
+
56
+ If the moduli are not co-prime, you may receive an incorrect result
57
+ if you use ``check=False``:
58
+
59
+ >>> crt([12, 6, 17], [3, 4, 2], check=False)
60
+ (954, 1224)
61
+ >>> [954 % m for m in [12, 6, 17]]
62
+ [6, 0, 2]
63
+ >>> crt([12, 6, 17], [3, 4, 2]) is None
64
+ True
65
+ >>> crt([3, 6], [2, 5])
66
+ (5, 6)
67
+
68
+ Note: the order of gf_crt's arguments is reversed relative to crt,
69
+ and that solve_congruence takes residue, modulus pairs.
70
+
71
+ Programmer's note: rather than checking that all pairs of moduli share
72
+ no GCD (an O(n**2) test) and rather than factoring all moduli and seeing
73
+ that there is no factor in common, a check that the result gives the
74
+ indicated residuals is performed -- an O(n) operation.
75
+
76
+ See Also
77
+ ========
78
+
79
+ solve_congruence
80
+ sympy.polys.galoistools.gf_crt : low level crt routine used by this routine
81
+ """
82
+ if check:
83
+ m = list(map(as_int, m))
84
+ v = list(map(as_int, v))
85
+
86
+ result = gf_crt(v, m, ZZ)
87
+ mm = prod(m)
88
+
89
+ if check:
90
+ if not all(v % m == result % m for v, m in zip(v, m)):
91
+ result = solve_congruence(*list(zip(v, m)),
92
+ check=False, symmetric=symmetric)
93
+ if result is None:
94
+ return result
95
+ result, mm = result
96
+
97
+ if symmetric:
98
+ return int(symmetric_residue(result, mm)), int(mm)
99
+ return int(result), int(mm)
100
+
101
+
102
+ def crt1(m):
103
+ """First part of Chinese Remainder Theorem, for multiple application.
104
+
105
+ Examples
106
+ ========
107
+
108
+ >>> from sympy.ntheory.modular import crt, crt1, crt2
109
+ >>> m = [99, 97, 95]
110
+ >>> v = [49, 76, 65]
111
+
112
+ The following two codes have the same result.
113
+
114
+ >>> crt(m, v)
115
+ (639985, 912285)
116
+
117
+ >>> mm, e, s = crt1(m)
118
+ >>> crt2(m, v, mm, e, s)
119
+ (639985, 912285)
120
+
121
+ However, it is faster when we want to fix ``m`` and
122
+ compute for multiple ``v``, i.e. the following cases:
123
+
124
+ >>> mm, e, s = crt1(m)
125
+ >>> vs = [[52, 21, 37], [19, 46, 76]]
126
+ >>> for v in vs:
127
+ ... print(crt2(m, v, mm, e, s))
128
+ (397042, 912285)
129
+ (803206, 912285)
130
+
131
+ See Also
132
+ ========
133
+
134
+ sympy.polys.galoistools.gf_crt1 : low level crt routine used by this routine
135
+ sympy.ntheory.modular.crt
136
+ sympy.ntheory.modular.crt2
137
+
138
+ """
139
+
140
+ return gf_crt1(m, ZZ)
141
+
142
+
143
+ def crt2(m, v, mm, e, s, symmetric=False):
144
+ """Second part of Chinese Remainder Theorem, for multiple application.
145
+
146
+ See ``crt1`` for usage.
147
+
148
+ Examples
149
+ ========
150
+
151
+ >>> from sympy.ntheory.modular import crt1, crt2
152
+ >>> mm, e, s = crt1([18, 42, 6])
153
+ >>> crt2([18, 42, 6], [0, 0, 0], mm, e, s)
154
+ (0, 4536)
155
+
156
+ See Also
157
+ ========
158
+
159
+ sympy.polys.galoistools.gf_crt2 : low level crt routine used by this routine
160
+ sympy.ntheory.modular.crt
161
+ sympy.ntheory.modular.crt1
162
+
163
+ """
164
+
165
+ result = gf_crt2(v, m, mm, e, s, ZZ)
166
+
167
+ if symmetric:
168
+ return int(symmetric_residue(result, mm)), int(mm)
169
+ return int(result), int(mm)
170
+
171
+
172
+ def solve_congruence(*remainder_modulus_pairs, **hint):
173
+ """Compute the integer ``n`` that has the residual ``ai`` when it is
174
+ divided by ``mi`` where the ``ai`` and ``mi`` are given as pairs to
175
+ this function: ((a1, m1), (a2, m2), ...). If there is no solution,
176
+ return None. Otherwise return ``n`` and its modulus.
177
+
178
+ The ``mi`` values need not be co-prime. If it is known that the moduli are
179
+ not co-prime then the hint ``check`` can be set to False (default=True) and
180
+ the check for a quicker solution via crt() (valid when the moduli are
181
+ co-prime) will be skipped.
182
+
183
+ If the hint ``symmetric`` is True (default is False), the value of ``n``
184
+ will be within 1/2 of the modulus, possibly negative.
185
+
186
+ Examples
187
+ ========
188
+
189
+ >>> from sympy.ntheory.modular import solve_congruence
190
+
191
+ What number is 2 mod 3, 3 mod 5 and 2 mod 7?
192
+
193
+ >>> solve_congruence((2, 3), (3, 5), (2, 7))
194
+ (23, 105)
195
+ >>> [23 % m for m in [3, 5, 7]]
196
+ [2, 3, 2]
197
+
198
+ If you prefer to work with all remainder in one list and
199
+ all moduli in another, send the arguments like this:
200
+
201
+ >>> solve_congruence(*zip((2, 3, 2), (3, 5, 7)))
202
+ (23, 105)
203
+
204
+ The moduli need not be co-prime; in this case there may or
205
+ may not be a solution:
206
+
207
+ >>> solve_congruence((2, 3), (4, 6)) is None
208
+ True
209
+
210
+ >>> solve_congruence((2, 3), (5, 6))
211
+ (5, 6)
212
+
213
+ The symmetric flag will make the result be within 1/2 of the modulus:
214
+
215
+ >>> solve_congruence((2, 3), (5, 6), symmetric=True)
216
+ (-1, 6)
217
+
218
+ See Also
219
+ ========
220
+
221
+ crt : high level routine implementing the Chinese Remainder Theorem
222
+
223
+ """
224
+ def combine(c1, c2):
225
+ """Return the tuple (a, m) which satisfies the requirement
226
+ that n = a + i*m satisfy n = a1 + j*m1 and n = a2 = k*m2.
227
+
228
+ References
229
+ ==========
230
+
231
+ .. [1] https://en.wikipedia.org/wiki/Method_of_successive_substitution
232
+ """
233
+ a1, m1 = c1
234
+ a2, m2 = c2
235
+ a, b, c = m1, a2 - a1, m2
236
+ g = gcd(a, b, c)
237
+ a, b, c = [i//g for i in [a, b, c]]
238
+ if a != 1:
239
+ g, inv_a, _ = gcdext(a, c)
240
+ if g != 1:
241
+ return None
242
+ b *= inv_a
243
+ a, m = a1 + m1*b, m1*c
244
+ return a, m
245
+
246
+ rm = remainder_modulus_pairs
247
+ symmetric = hint.get('symmetric', False)
248
+
249
+ if hint.get('check', True):
250
+ rm = [(as_int(r), as_int(m)) for r, m in rm]
251
+
252
+ # ignore redundant pairs but raise an error otherwise; also
253
+ # make sure that a unique set of bases is sent to gf_crt if
254
+ # they are all prime.
255
+ #
256
+ # The routine will work out less-trivial violations and
257
+ # return None, e.g. for the pairs (1,3) and (14,42) there
258
+ # is no answer because 14 mod 42 (having a gcd of 14) implies
259
+ # (14/2) mod (42/2), (14/7) mod (42/7) and (14/14) mod (42/14)
260
+ # which, being 0 mod 3, is inconsistent with 1 mod 3. But to
261
+ # preprocess the input beyond checking of another pair with 42
262
+ # or 3 as the modulus (for this example) is not necessary.
263
+ uniq = {}
264
+ for r, m in rm:
265
+ r %= m
266
+ if m in uniq:
267
+ if r != uniq[m]:
268
+ return None
269
+ continue
270
+ uniq[m] = r
271
+ rm = [(r, m) for m, r in uniq.items()]
272
+ del uniq
273
+
274
+ # if the moduli are co-prime, the crt will be significantly faster;
275
+ # checking all pairs for being co-prime gets to be slow but a prime
276
+ # test is a good trade-off
277
+ if all(isprime(m) for r, m in rm):
278
+ r, m = list(zip(*rm))
279
+ return crt(m, r, symmetric=symmetric, check=False)
280
+
281
+ rv = (0, 1)
282
+ for rmi in rm:
283
+ rv = combine(rv, rmi)
284
+ if rv is None:
285
+ break
286
+ n, m = rv
287
+ n = n % m
288
+ else:
289
+ if symmetric:
290
+ return symmetric_residue(n, m), m
291
+ return n, m
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/multinomial.py ADDED
@@ -0,0 +1,188 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from sympy.utilities.misc import as_int
2
+
3
+
4
+ def binomial_coefficients(n):
5
+ """Return a dictionary containing pairs :math:`{(k1,k2) : C_kn}` where
6
+ :math:`C_kn` are binomial coefficients and :math:`n=k1+k2`.
7
+
8
+ Examples
9
+ ========
10
+
11
+ >>> from sympy.ntheory import binomial_coefficients
12
+ >>> binomial_coefficients(9)
13
+ {(0, 9): 1, (1, 8): 9, (2, 7): 36, (3, 6): 84,
14
+ (4, 5): 126, (5, 4): 126, (6, 3): 84, (7, 2): 36, (8, 1): 9, (9, 0): 1}
15
+
16
+ See Also
17
+ ========
18
+
19
+ binomial_coefficients_list, multinomial_coefficients
20
+ """
21
+ n = as_int(n)
22
+ d = {(0, n): 1, (n, 0): 1}
23
+ a = 1
24
+ for k in range(1, n//2 + 1):
25
+ a = (a * (n - k + 1))//k
26
+ d[k, n - k] = d[n - k, k] = a
27
+ return d
28
+
29
+
30
+ def binomial_coefficients_list(n):
31
+ """ Return a list of binomial coefficients as rows of the Pascal's
32
+ triangle.
33
+
34
+ Examples
35
+ ========
36
+
37
+ >>> from sympy.ntheory import binomial_coefficients_list
38
+ >>> binomial_coefficients_list(9)
39
+ [1, 9, 36, 84, 126, 126, 84, 36, 9, 1]
40
+
41
+ See Also
42
+ ========
43
+
44
+ binomial_coefficients, multinomial_coefficients
45
+ """
46
+ n = as_int(n)
47
+ d = [1] * (n + 1)
48
+ a = 1
49
+ for k in range(1, n//2 + 1):
50
+ a = (a * (n - k + 1))//k
51
+ d[k] = d[n - k] = a
52
+ return d
53
+
54
+
55
+ def multinomial_coefficients(m, n):
56
+ r"""Return a dictionary containing pairs ``{(k1,k2,..,km) : C_kn}``
57
+ where ``C_kn`` are multinomial coefficients such that
58
+ ``n=k1+k2+..+km``.
59
+
60
+ Examples
61
+ ========
62
+
63
+ >>> from sympy.ntheory import multinomial_coefficients
64
+ >>> multinomial_coefficients(2, 5) # indirect doctest
65
+ {(0, 5): 1, (1, 4): 5, (2, 3): 10, (3, 2): 10, (4, 1): 5, (5, 0): 1}
66
+
67
+ Notes
68
+ =====
69
+
70
+ The algorithm is based on the following result:
71
+
72
+ .. math::
73
+ \binom{n}{k_1, \ldots, k_m} =
74
+ \frac{k_1 + 1}{n - k_1} \sum_{i=2}^m \binom{n}{k_1 + 1, \ldots, k_i - 1, \ldots}
75
+
76
+ Code contributed to Sage by Yann Laigle-Chapuy, copied with permission
77
+ of the author.
78
+
79
+ See Also
80
+ ========
81
+
82
+ binomial_coefficients_list, binomial_coefficients
83
+ """
84
+ m = as_int(m)
85
+ n = as_int(n)
86
+ if not m:
87
+ if n:
88
+ return {}
89
+ return {(): 1}
90
+ if m == 2:
91
+ return binomial_coefficients(n)
92
+ if m >= 2*n and n > 1:
93
+ return dict(multinomial_coefficients_iterator(m, n))
94
+ t = [n] + [0] * (m - 1)
95
+ r = {tuple(t): 1}
96
+ if n:
97
+ j = 0 # j will be the leftmost nonzero position
98
+ else:
99
+ j = m
100
+ # enumerate tuples in co-lex order
101
+ while j < m - 1:
102
+ # compute next tuple
103
+ tj = t[j]
104
+ if j:
105
+ t[j] = 0
106
+ t[0] = tj
107
+ if tj > 1:
108
+ t[j + 1] += 1
109
+ j = 0
110
+ start = 1
111
+ v = 0
112
+ else:
113
+ j += 1
114
+ start = j + 1
115
+ v = r[tuple(t)]
116
+ t[j] += 1
117
+ # compute the value
118
+ # NB: the initialization of v was done above
119
+ for k in range(start, m):
120
+ if t[k]:
121
+ t[k] -= 1
122
+ v += r[tuple(t)]
123
+ t[k] += 1
124
+ t[0] -= 1
125
+ r[tuple(t)] = (v * tj) // (n - t[0])
126
+ return r
127
+
128
+
129
+ def multinomial_coefficients_iterator(m, n, _tuple=tuple):
130
+ """multinomial coefficient iterator
131
+
132
+ This routine has been optimized for `m` large with respect to `n` by taking
133
+ advantage of the fact that when the monomial tuples `t` are stripped of
134
+ zeros, their coefficient is the same as that of the monomial tuples from
135
+ ``multinomial_coefficients(n, n)``. Therefore, the latter coefficients are
136
+ precomputed to save memory and time.
137
+
138
+ >>> from sympy.ntheory.multinomial import multinomial_coefficients
139
+ >>> m53, m33 = multinomial_coefficients(5,3), multinomial_coefficients(3,3)
140
+ >>> m53[(0,0,0,1,2)] == m53[(0,0,1,0,2)] == m53[(1,0,2,0,0)] == m33[(0,1,2)]
141
+ True
142
+
143
+ Examples
144
+ ========
145
+
146
+ >>> from sympy.ntheory.multinomial import multinomial_coefficients_iterator
147
+ >>> it = multinomial_coefficients_iterator(20,3)
148
+ >>> next(it)
149
+ ((3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0), 1)
150
+ """
151
+ m = as_int(m)
152
+ n = as_int(n)
153
+ if m < 2*n or n == 1:
154
+ mc = multinomial_coefficients(m, n)
155
+ yield from mc.items()
156
+ else:
157
+ mc = multinomial_coefficients(n, n)
158
+ mc1 = {}
159
+ for k, v in mc.items():
160
+ mc1[_tuple(filter(None, k))] = v
161
+ mc = mc1
162
+
163
+ t = [n] + [0] * (m - 1)
164
+ t1 = _tuple(t)
165
+ b = _tuple(filter(None, t1))
166
+ yield (t1, mc[b])
167
+ if n:
168
+ j = 0 # j will be the leftmost nonzero position
169
+ else:
170
+ j = m
171
+ # enumerate tuples in co-lex order
172
+ while j < m - 1:
173
+ # compute next tuple
174
+ tj = t[j]
175
+ if j:
176
+ t[j] = 0
177
+ t[0] = tj
178
+ if tj > 1:
179
+ t[j + 1] += 1
180
+ j = 0
181
+ else:
182
+ j += 1
183
+ t[j] += 1
184
+
185
+ t[0] -= 1
186
+ t1 = _tuple(t)
187
+ b = _tuple(filter(None, t1))
188
+ yield (t1, mc[b])
infer_4_47_1/lib/python3.10/site-packages/sympy/ntheory/partitions_.py ADDED
@@ -0,0 +1,278 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ from mpmath.libmp import (fzero, from_int, from_rational,
2
+ fone, fhalf, bitcount, to_int, mpf_mul, mpf_div, mpf_sub,
3
+ mpf_add, mpf_sqrt, mpf_pi, mpf_cosh_sinh, mpf_cos, mpf_sin)
4
+ from sympy.external.gmpy import gcd, legendre, jacobi
5
+ from .residue_ntheory import _sqrt_mod_prime_power, is_quad_residue
6
+ from sympy.utilities.decorator import deprecated
7
+ from sympy.utilities.memoization import recurrence_memo
8
+
9
+ import math
10
+ from itertools import count
11
+
12
+ def _pre():
13
+ maxn = 10**5
14
+ global _factor
15
+ global _totient
16
+ _factor = [0]*maxn
17
+ _totient = [1]*maxn
18
+ lim = int(maxn**0.5) + 5
19
+ for i in range(2, lim):
20
+ if _factor[i] == 0:
21
+ for j in range(i*i, maxn, i):
22
+ if _factor[j] == 0:
23
+ _factor[j] = i
24
+ for i in range(2, maxn):
25
+ if _factor[i] == 0:
26
+ _factor[i] = i
27
+ _totient[i] = i-1
28
+ continue
29
+ x = _factor[i]
30
+ y = i//x
31
+ if y % x == 0:
32
+ _totient[i] = _totient[y]*x
33
+ else:
34
+ _totient[i] = _totient[y]*(x - 1)
35
+
36
+ def _a(n, k, prec):
37
+ """ Compute the inner sum in HRR formula [1]_
38
+
39
+ References
40
+ ==========
41
+
42
+ .. [1] https://msp.org/pjm/1956/6-1/pjm-v6-n1-p18-p.pdf
43
+
44
+ """
45
+ if k == 1:
46
+ return fone
47
+
48
+ k1 = k
49
+ e = 0
50
+ p = _factor[k]
51
+ while k1 % p == 0:
52
+ k1 //= p
53
+ e += 1
54
+ k2 = k//k1 # k2 = p^e
55
+ v = 1 - 24*n
56
+ pi = mpf_pi(prec)
57
+
58
+ if k1 == 1:
59
+ # k = p^e
60
+ if p == 2:
61
+ mod = 8*k
62
+ v = mod + v % mod
63
+ v = (v*pow(9, k - 1, mod)) % mod
64
+ m = _sqrt_mod_prime_power(v, 2, e + 3)[0]
65
+ arg = mpf_div(mpf_mul(
66
+ from_int(4*m), pi, prec), from_int(mod), prec)
67
+ return mpf_mul(mpf_mul(
68
+ from_int((-1)**e*jacobi(m - 1, m)),
69
+ mpf_sqrt(from_int(k), prec), prec),
70
+ mpf_sin(arg, prec), prec)
71
+ if p == 3:
72
+ mod = 3*k
73
+ v = mod + v % mod
74
+ if e > 1:
75
+ v = (v*pow(64, k//3 - 1, mod)) % mod
76
+ m = _sqrt_mod_prime_power(v, 3, e + 1)[0]
77
+ arg = mpf_div(mpf_mul(from_int(4*m), pi, prec),
78
+ from_int(mod), prec)
79
+ return mpf_mul(mpf_mul(
80
+ from_int(2*(-1)**(e + 1)*legendre(m, 3)),
81
+ mpf_sqrt(from_int(k//3), prec), prec),
82
+ mpf_sin(arg, prec), prec)
83
+ v = k + v % k
84
+ if v % p == 0:
85
+ if e == 1:
86
+ return mpf_mul(
87
+ from_int(jacobi(3, k)),
88
+ mpf_sqrt(from_int(k), prec), prec)
89
+ return fzero
90
+ if not is_quad_residue(v, p):
91
+ return fzero
92
+ _phi = p**(e - 1)*(p - 1)
93
+ v = (v*pow(576, _phi - 1, k))
94
+ m = _sqrt_mod_prime_power(v, p, e)[0]
95
+ arg = mpf_div(
96
+ mpf_mul(from_int(4*m), pi, prec),
97
+ from_int(k), prec)
98
+ return mpf_mul(mpf_mul(
99
+ from_int(2*jacobi(3, k)),
100
+ mpf_sqrt(from_int(k), prec), prec),
101
+ mpf_cos(arg, prec), prec)
102
+
103
+ if p != 2 or e >= 3:
104
+ d1, d2 = gcd(k1, 24), gcd(k2, 24)
105
+ e = 24//(d1*d2)
106
+ n1 = ((d2*e*n + (k2**2 - 1)//d1)*
107
+ pow(e*k2*k2*d2, _totient[k1] - 1, k1)) % k1
108
+ n2 = ((d1*e*n + (k1**2 - 1)//d2)*
109
+ pow(e*k1*k1*d1, _totient[k2] - 1, k2)) % k2
110
+ return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec)
111
+ if e == 2:
112
+ n1 = ((8*n + 5)*pow(128, _totient[k1] - 1, k1)) % k1
113
+ n2 = (4 + ((n - 2 - (k1**2 - 1)//8)*(k1**2)) % 4) % 4
114
+ return mpf_mul(mpf_mul(
115
+ from_int(-1),
116
+ _a(n1, k1, prec), prec),
117
+ _a(n2, k2, prec))
118
+ n1 = ((8*n + 1)*pow(32, _totient[k1] - 1, k1)) % k1
119
+ n2 = (2 + (n - (k1**2 - 1)//8) % 2) % 2
120
+ return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec)
121
+
122
+ def _d(n, j, prec, sq23pi, sqrt8):
123
+ """
124
+ Compute the sinh term in the outer sum of the HRR formula.
125
+ The constants sqrt(2/3*pi) and sqrt(8) must be precomputed.
126
+ """
127
+ j = from_int(j)
128
+ pi = mpf_pi(prec)
129
+ a = mpf_div(sq23pi, j, prec)
130
+ b = mpf_sub(from_int(n), from_rational(1, 24, prec), prec)
131
+ c = mpf_sqrt(b, prec)
132
+ ch, sh = mpf_cosh_sinh(mpf_mul(a, c), prec)
133
+ D = mpf_div(
134
+ mpf_sqrt(j, prec),
135
+ mpf_mul(mpf_mul(sqrt8, b), pi), prec)
136
+ E = mpf_sub(mpf_mul(a, ch), mpf_div(sh, c, prec), prec)
137
+ return mpf_mul(D, E)
138
+
139
+
140
+ @recurrence_memo([1, 1])
141
+ def _partition_rec(n: int, prev) -> int:
142
+ """ Calculate the partition function P(n)
143
+
144
+ Parameters
145
+ ==========
146
+
147
+ n : int
148
+ nonnegative integer
149
+
150
+ """
151
+ v = 0
152
+ penta = 0 # pentagonal number: 1, 5, 12, ...
153
+ for i in count():
154
+ penta += 3*i + 1
155
+ np = n - penta
156
+ if np < 0:
157
+ break
158
+ s = prev[np]
159
+ np -= i + 1
160
+ # np = n - gp where gp = generalized pentagonal: 2, 7, 15, ...
161
+ if 0 <= np:
162
+ s += prev[np]
163
+ v += -s if i % 2 else s
164
+ return v
165
+
166
+
167
+ def _partition(n: int) -> int:
168
+ """ Calculate the partition function P(n)
169
+
170
+ Parameters
171
+ ==========
172
+
173
+ n : int
174
+
175
+ """
176
+ if n < 0:
177
+ return 0
178
+ if (n <= 200_000 and n - _partition_rec.cache_length() < 70 or
179
+ _partition_rec.cache_length() == 2 and n < 14_400):
180
+ # There will be 2*10**5 elements created here
181
+ # and n elements created by partition, so in case we
182
+ # are going to be working with small n, we just
183
+ # use partition to calculate (and cache) the values
184
+ # since lookup is used there while summation, using
185
+ # _factor and _totient, will be used below. But we
186
+ # only do so if n is relatively close to the length
187
+ # of the cache since doing 1 calculation here is about
188
+ # the same as adding 70 elements to the cache. In addition,
189
+ # the startup here costs about the same as calculating the first
190
+ # 14,400 values via partition, so we delay startup here unless n
191
+ # is smaller than that.
192
+ return _partition_rec(n)
193
+ if '_factor' not in globals():
194
+ _pre()
195
+ # Estimate number of bits in p(n). This formula could be tidied
196
+ pbits = int((
197
+ math.pi*(2*n/3.)**0.5 -
198
+ math.log(4*n))/math.log(10) + 1) * \
199
+ math.log2(10)
200
+ prec = p = int(pbits*1.1 + 100)
201
+
202
+ # find the number of terms needed so rounded sum will be accurate
203
+ # using Rademacher's bound M(n, N) for the remainder after a partial
204
+ # sum of N terms (https://arxiv.org/pdf/1205.5991.pdf, (1.8))
205
+ c1 = 44*math.pi**2/(225*math.sqrt(3))
206
+ c2 = math.pi*math.sqrt(2)/75
207
+ c3 = math.pi*math.sqrt(2/3)
208
+ def _M(n, N):
209
+ sqrt = math.sqrt
210
+ return c1/sqrt(N) + c2*sqrt(N/(n - 1))*math.sinh(c3*sqrt(n)/N)
211
+ big = max(9, math.ceil(n**0.5)) # should be too large (for n > 65, ceil should work)
212
+ assert _M(n, big) < 0.5 # else double big until too large
213
+ while big > 40 and _M(n, big) < 0.5:
214
+ big //= 2
215
+ small = big
216
+ big = small*2
217
+ while big - small > 1:
218
+ N = (big + small)//2
219
+ if (er := _M(n, N)) < 0.5:
220
+ big = N
221
+ elif er >= 0.5:
222
+ small = N
223
+ M = big # done with function M; now have value
224
+
225
+ # sanity check for expected size of answer
226
+ if M > 10**5: # i.e. M > maxn
227
+ raise ValueError("Input too big") # i.e. n > 149832547102
228
+
229
+ # calculate it
230
+ s = fzero
231
+ sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p)
232
+ sqrt8 = mpf_sqrt(from_int(8), p)
233
+ for q in range(1, M):
234
+ a = _a(n, q, p)
235
+ d = _d(n, q, p, sq23pi, sqrt8)
236
+ s = mpf_add(s, mpf_mul(a, d), prec)
237
+ # On average, the terms decrease rapidly in magnitude.
238
+ # Dynamically reducing the precision greatly improves
239
+ # performance.
240
+ p = bitcount(abs(to_int(d))) + 50
241
+ return int(to_int(mpf_add(s, fhalf, prec)))
242
+
243
+
244
+ @deprecated("""\
245
+ The `sympy.ntheory.partitions_.npartitions` has been moved to `sympy.functions.combinatorial.numbers.partition`.""",
246
+ deprecated_since_version="1.13",
247
+ active_deprecations_target='deprecated-ntheory-symbolic-functions')
248
+ def npartitions(n, verbose=False):
249
+ """
250
+ Calculate the partition function P(n), i.e. the number of ways that
251
+ n can be written as a sum of positive integers.
252
+
253
+ .. deprecated:: 1.13
254
+
255
+ The ``npartitions`` function is deprecated. Use :class:`sympy.functions.combinatorial.numbers.partition`
256
+ instead. See its documentation for more information. See
257
+ :ref:`deprecated-ntheory-symbolic-functions` for details.
258
+
259
+ P(n) is computed using the Hardy-Ramanujan-Rademacher formula [1]_.
260
+
261
+
262
+ The correctness of this implementation has been tested through $10^{10}$.
263
+
264
+ Examples
265
+ ========
266
+
267
+ >>> from sympy.functions.combinatorial.numbers import partition
268
+ >>> partition(25)
269
+ 1958
270
+
271
+ References
272
+ ==========
273
+
274
+ .. [1] https://mathworld.wolfram.com/PartitionFunctionP.html
275
+
276
+ """
277
+ from sympy.functions.combinatorial.numbers import partition as func_partition
278
+ return func_partition(n)
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@@ -0,0 +1,77 @@
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
+ import itertools
2
+ from sympy.core import GoldenRatio as phi
3
+ from sympy.core.numbers import (Rational, pi)
4
+ from sympy.core.singleton import S
5
+ from sympy.functions.elementary.miscellaneous import sqrt
6
+ from sympy.ntheory.continued_fraction import \
7
+ (continued_fraction_periodic as cf_p,
8
+ continued_fraction_iterator as cf_i,
9
+ continued_fraction_convergents as cf_c,
10
+ continued_fraction_reduce as cf_r,
11
+ continued_fraction as cf)
12
+ from sympy.testing.pytest import raises
13
+
14
+
15
+ def test_continued_fraction():
16
+ assert cf_p(1, 1, 10, 0) == cf_p(1, 1, 0, 1)
17
+ assert cf_p(1, -1, 10, 1) == cf_p(-1, 1, 10, -1)
18
+ t = sqrt(2)
19
+ assert cf((1 + t)*(1 - t)) == cf(-1)
20
+ for n in [0, 2, Rational(2, 3), sqrt(2), 3*sqrt(2), 1 + 2*sqrt(3)/5,
21
+ (2 - 3*sqrt(5))/7, 1 + sqrt(2), (-5 + sqrt(17))/4]:
22
+ assert (cf_r(cf(n)) - n).expand() == 0
23
+ assert (cf_r(cf(-n)) + n).expand() == 0
24
+ raises(ValueError, lambda: cf(sqrt(2 + sqrt(3))))
25
+ raises(ValueError, lambda: cf(sqrt(2) + sqrt(3)))
26
+ raises(ValueError, lambda: cf(pi))
27
+ raises(ValueError, lambda: cf(.1))
28
+
29
+ raises(ValueError, lambda: cf_p(1, 0, 0))
30
+ raises(ValueError, lambda: cf_p(1, 1, -1))
31
+ assert cf_p(4, 3, 0) == [1, 3]
32
+ assert cf_p(0, 3, 5) == [0, 1, [2, 1, 12, 1, 2, 2]]
33
+ assert cf_p(1, 1, 0) == [1]
34
+ assert cf_p(3, 4, 0) == [0, 1, 3]
35
+ assert cf_p(4, 5, 0) == [0, 1, 4]
36
+ assert cf_p(5, 6, 0) == [0, 1, 5]
37
+ assert cf_p(11, 13, 0) == [0, 1, 5, 2]
38
+ assert cf_p(16, 19, 0) == [0, 1, 5, 3]
39
+ assert cf_p(27, 32, 0) == [0, 1, 5, 2, 2]
40
+ assert cf_p(1, 2, 5) == [[1]]
41
+ assert cf_p(0, 1, 2) == [1, [2]]
42
+ assert cf_p(6, 7, 49) == [1, 1, 6]
43
+ assert cf_p(3796, 1387, 0) == [2, 1, 2, 1, 4]
44
+ assert cf_p(3245, 10000) == [0, 3, 12, 4, 13]
45
+ assert cf_p(1932, 2568) == [0, 1, 3, 26, 2]
46
+ assert cf_p(6589, 2569) == [2, 1, 1, 3, 2, 1, 3, 1, 23]
47
+
48
+ def take(iterator, n=7):
49
+ return list(itertools.islice(iterator, n))
50
+
51
+ assert take(cf_i(phi)) == [1, 1, 1, 1, 1, 1, 1]
52
+ assert take(cf_i(pi)) == [3, 7, 15, 1, 292, 1, 1]
53
+
54
+ assert list(cf_i(Rational(17, 12))) == [1, 2, 2, 2]
55
+ assert list(cf_i(Rational(-17, 12))) == [-2, 1, 1, 2, 2]
56
+
57
+ assert list(cf_c([1, 6, 1, 8])) == [S.One, Rational(7, 6), Rational(8, 7), Rational(71, 62)]
58
+ assert list(cf_c([2])) == [S(2)]
59
+ assert list(cf_c([1, 1, 1, 1, 1, 1, 1])) == [S.One, S(2), Rational(3, 2), Rational(5, 3),
60
+ Rational(8, 5), Rational(13, 8), Rational(21, 13)]
61
+ assert list(cf_c([1, 6, Rational(-1, 2), 4])) == [S.One, Rational(7, 6), Rational(5, 4), Rational(3, 2)]
62
+ assert take(cf_c([[1]])) == [S.One, S(2), Rational(3, 2), Rational(5, 3), Rational(8, 5),
63
+ Rational(13, 8), Rational(21, 13)]
64
+ assert take(cf_c([1, [1, 2]])) == [S.One, S(2), Rational(5, 3), Rational(7, 4), Rational(19, 11),
65
+ Rational(26, 15), Rational(71, 41)]
66
+
67
+ cf_iter_e = (2 if i == 1 else i // 3 * 2 if i % 3 == 0 else 1 for i in itertools.count(1))
68
+ assert take(cf_c(cf_iter_e)) == [S(2), S(3), Rational(8, 3), Rational(11, 4), Rational(19, 7),
69
+ Rational(87, 32), Rational(106, 39)]
70
+
71
+ assert cf_r([1, 6, 1, 8]) == Rational(71, 62)
72
+ assert cf_r([3]) == S(3)
73
+ assert cf_r([-1, 5, 1, 4]) == Rational(-24, 29)
74
+ assert (cf_r([0, 1, 1, 7, [24, 8]]) - (sqrt(3) + 2)/7).expand() == 0
75
+ assert cf_r([1, 5, 9]) == Rational(55, 46)
76
+ assert (cf_r([[1]]) - (sqrt(5) + 1)/2).expand() == 0
77
+ assert cf_r([-3, 1, 1, [2]]) == -1 - sqrt(2)