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numpy.record.argsort method record.argsort()
Scalar method identical to the corresponding array attribute. Please see ndarray.argsort. | numpy.reference.generated.numpy.record.argsort |
numpy.record.astype method record.astype()
Scalar method identical to the corresponding array attribute. Please see ndarray.astype. | numpy.reference.generated.numpy.record.astype |
numpy.record.base attribute record.base
base object | numpy.reference.generated.numpy.record.base |
numpy.record.byteswap method record.byteswap()
Scalar method identical to the corresponding array attribute. Please see ndarray.byteswap. | numpy.reference.generated.numpy.record.byteswap |
numpy.record.choose method record.choose()
Scalar method identical to the corresponding array attribute. Please see ndarray.choose. | numpy.reference.generated.numpy.record.choose |
numpy.record.clip method record.clip()
Scalar method identical to the corresponding array attribute. Please see ndarray.clip. | numpy.reference.generated.numpy.record.clip |
numpy.record.compress method record.compress()
Scalar method identical to the corresponding array attribute. Please see ndarray.compress. | numpy.reference.generated.numpy.record.compress |
numpy.record.conjugate method record.conjugate()
Scalar method identical to the corresponding array attribute. Please see ndarray.conjugate. | numpy.reference.generated.numpy.record.conjugate |
numpy.record.copy method record.copy()
Scalar method identical to the corresponding array attribute. Please see ndarray.copy. | numpy.reference.generated.numpy.record.copy |
numpy.record.cumprod method record.cumprod()
Scalar method identical to the corresponding array attribute. Please see ndarray.cumprod. | numpy.reference.generated.numpy.record.cumprod |
numpy.record.cumsum method record.cumsum()
Scalar method identical to the corresponding array attribute. Please see ndarray.cumsum. | numpy.reference.generated.numpy.record.cumsum |
numpy.record.data attribute record.data
Pointer to start of data. | numpy.reference.generated.numpy.record.data |
numpy.record.diagonal method record.diagonal()
Scalar method identical to the corresponding array attribute. Please see ndarray.diagonal. | numpy.reference.generated.numpy.record.diagonal |
numpy.record.dump method record.dump()
Scalar method identical to the corresponding array attribute. Please see ndarray.dump. | numpy.reference.generated.numpy.record.dump |
numpy.record.dumps method record.dumps()
Scalar method identical to the corresponding array attribute. Please see ndarray.dumps. | numpy.reference.generated.numpy.record.dumps |
numpy.record.fill method record.fill()
Scalar method identical to the corresponding array attribute. Please see ndarray.fill. | numpy.reference.generated.numpy.record.fill |
numpy.record.flags attribute record.flags
integer value of flags | numpy.reference.generated.numpy.record.flags |
numpy.record.flat attribute record.flat
A 1-D view of the scalar. | numpy.reference.generated.numpy.record.flat |
numpy.record.flatten method record.flatten()
Scalar method identical to the corresponding array attribute. Please see ndarray.flatten. | numpy.reference.generated.numpy.record.flatten |
numpy.record.getfield method record.getfield()
Scalar method identical to the corresponding array attribute. Please see ndarray.getfield. | numpy.reference.generated.numpy.record.getfield |
numpy.record.item method record.item()
Scalar method identical to the corresponding array attribute. Please see ndarray.item. | numpy.reference.generated.numpy.record.item |
numpy.record.itemset method record.itemset()
Scalar method identical to the corresponding array attribute. Please see ndarray.itemset. | numpy.reference.generated.numpy.record.itemset |
numpy.record.itemsize attribute record.itemsize
The length of one element in bytes. | numpy.reference.generated.numpy.record.itemsize |
numpy.record.max method record.max()
Scalar method identical to the corresponding array attribute. Please see ndarray.max. | numpy.reference.generated.numpy.record.max |
numpy.record.mean method record.mean()
Scalar method identical to the corresponding array attribute. Please see ndarray.mean. | numpy.reference.generated.numpy.record.mean |
numpy.record.min method record.min()
Scalar method identical to the corresponding array attribute. Please see ndarray.min. | numpy.reference.generated.numpy.record.min |
numpy.record.nbytes attribute record.nbytes
The length of the scalar in bytes. | numpy.reference.generated.numpy.record.nbytes |
numpy.record.ndim attribute record.ndim
The number of array dimensions. | numpy.reference.generated.numpy.record.ndim |
numpy.record.newbyteorder method record.newbyteorder(new_order='S', /)
Return a new dtype with a different byte order. Changes are also made in all fields and sub-arrays of the data type. The new_order code can be any from the following: ‘S’ - swap dtype from current to opposite endian {‘<’, ‘little’} - little endian {‘>’, ‘big’} - big endian {‘=’, ‘native’} - native order {‘|’, ‘I’} - ignore (no change to byte order) Parameters
new_orderstr, optional
Byte order to force; a value from the byte order specifications above. The default value (‘S’) results in swapping the current byte order. Returns
new_dtypedtype
New dtype object with the given change to the byte order. | numpy.reference.generated.numpy.record.newbyteorder |
numpy.record.nonzero method record.nonzero()
Scalar method identical to the corresponding array attribute. Please see ndarray.nonzero. | numpy.reference.generated.numpy.record.nonzero |
numpy.record.pprint method record.pprint()[source]
Pretty-print all fields. | numpy.reference.generated.numpy.record.pprint |
numpy.record.prod method record.prod()
Scalar method identical to the corresponding array attribute. Please see ndarray.prod. | numpy.reference.generated.numpy.record.prod |
numpy.record.ptp method record.ptp()
Scalar method identical to the corresponding array attribute. Please see ndarray.ptp. | numpy.reference.generated.numpy.record.ptp |
numpy.record.put method record.put()
Scalar method identical to the corresponding array attribute. Please see ndarray.put. | numpy.reference.generated.numpy.record.put |
numpy.record.ravel method record.ravel()
Scalar method identical to the corresponding array attribute. Please see ndarray.ravel. | numpy.reference.generated.numpy.record.ravel |
numpy.record.repeat method record.repeat()
Scalar method identical to the corresponding array attribute. Please see ndarray.repeat. | numpy.reference.generated.numpy.record.repeat |
numpy.record.reshape method record.reshape()
Scalar method identical to the corresponding array attribute. Please see ndarray.reshape. | numpy.reference.generated.numpy.record.reshape |
numpy.record.resize method record.resize()
Scalar method identical to the corresponding array attribute. Please see ndarray.resize. | numpy.reference.generated.numpy.record.resize |
numpy.record.round method record.round()
Scalar method identical to the corresponding array attribute. Please see ndarray.round. | numpy.reference.generated.numpy.record.round |
numpy.record.searchsorted method record.searchsorted()
Scalar method identical to the corresponding array attribute. Please see ndarray.searchsorted. | numpy.reference.generated.numpy.record.searchsorted |
numpy.record.setfield method record.setfield()
Scalar method identical to the corresponding array attribute. Please see ndarray.setfield. | numpy.reference.generated.numpy.record.setfield |
numpy.record.setflags method record.setflags()
Scalar method identical to the corresponding array attribute. Please see ndarray.setflags. | numpy.reference.generated.numpy.record.setflags |
numpy.record.size attribute record.size
The number of elements in the gentype. | numpy.reference.generated.numpy.record.size |
numpy.record.sort method record.sort()
Scalar method identical to the corresponding array attribute. Please see ndarray.sort. | numpy.reference.generated.numpy.record.sort |
numpy.record.squeeze method record.squeeze()
Scalar method identical to the corresponding array attribute. Please see ndarray.squeeze. | numpy.reference.generated.numpy.record.squeeze |
numpy.record.std method record.std()
Scalar method identical to the corresponding array attribute. Please see ndarray.std. | numpy.reference.generated.numpy.record.std |
numpy.record.strides attribute record.strides
Tuple of bytes steps in each dimension. | numpy.reference.generated.numpy.record.strides |
numpy.record.sum method record.sum()
Scalar method identical to the corresponding array attribute. Please see ndarray.sum. | numpy.reference.generated.numpy.record.sum |
numpy.record.swapaxes method record.swapaxes()
Scalar method identical to the corresponding array attribute. Please see ndarray.swapaxes. | numpy.reference.generated.numpy.record.swapaxes |
numpy.record.T attribute record.T
Scalar attribute identical to the corresponding array attribute. Please see ndarray.T. | numpy.reference.generated.numpy.record.t |
numpy.record.take method record.take()
Scalar method identical to the corresponding array attribute. Please see ndarray.take. | numpy.reference.generated.numpy.record.take |
numpy.record.tofile method record.tofile()
Scalar method identical to the corresponding array attribute. Please see ndarray.tofile. | numpy.reference.generated.numpy.record.tofile |
numpy.record.tolist method record.tolist()
Scalar method identical to the corresponding array attribute. Please see ndarray.tolist. | numpy.reference.generated.numpy.record.tolist |
numpy.record.tostring method record.tostring()
Scalar method identical to the corresponding array attribute. Please see ndarray.tostring. | numpy.reference.generated.numpy.record.tostring |
numpy.record.trace method record.trace()
Scalar method identical to the corresponding array attribute. Please see ndarray.trace. | numpy.reference.generated.numpy.record.trace |
numpy.record.transpose method record.transpose()
Scalar method identical to the corresponding array attribute. Please see ndarray.transpose. | numpy.reference.generated.numpy.record.transpose |
numpy.record.var method record.var()
Scalar method identical to the corresponding array attribute. Please see ndarray.var. | numpy.reference.generated.numpy.record.var |
numpy.record.view method record.view()
Scalar method identical to the corresponding array attribute. Please see ndarray.view. | numpy.reference.generated.numpy.record.view |
NumPy Reference Release
1.22 Date
December 31, 2021 This reference manual details functions, modules, and objects included in NumPy, describing what they are and what they do. For learning how to use NumPy, see the complete documentation.
Array objects The N-dimensional array (ndarray) Scalars Data type objects (dtype) Indexing routines Iterating Over Arrays Standard array subclasses Masked arrays The Array Interface Datetimes and Timedeltas Constants
Universal functions (ufunc) ufunc Available ufuncs
Routines Array creation routines Array manipulation routines Binary operations String operations C-Types Foreign Function Interface (numpy.ctypeslib) Datetime Support Functions Data type routines Optionally SciPy-accelerated routines (numpy.dual) Mathematical functions with automatic domain (numpy.emath) Floating point error handling Discrete Fourier Transform (numpy.fft) Functional programming NumPy-specific help functions Input and output Linear algebra (numpy.linalg) Logic functions Masked array operations Mathematical functions Matrix library (numpy.matlib) Miscellaneous routines Padding Arrays Polynomials Random sampling (numpy.random) Set routines Sorting, searching, and counting Statistics Test Support (numpy.testing) Window functions
Typing (numpy.typing) Mypy plugin Differences from the runtime NumPy API API
Global State Performance-Related Options Interoperability-Related Options Debugging-Related Options
Packaging (numpy.distutils) Modules in numpy.distutils Configuration class Building Installable C libraries Conversion of .src files
NumPy Distutils - Users Guide SciPy structure Requirements for SciPy packages The setup.py file The __init__.py file Extra features in NumPy Distutils
NumPy C-API Python Types and C-Structures System configuration Data Type API Array API Array Iterator API UFunc API Generalized Universal Function API NumPy core libraries C API Deprecations Memory management in NumPy
SIMD Optimizations Build options for compilation Understanding CPU Dispatching, How the NumPy dispatcher works? Dive into the CPU dispatcher
NumPy and SWIG numpy.i: a SWIG Interface File for NumPy Testing the numpy.i Typemaps Acknowledgements Large parts of this manual originate from Travis E. Oliphant’s book Guide to NumPy (which generously entered Public Domain in August 2008). The reference documentation for many of the functions are written by numerous contributors and developers of NumPy. | numpy.reference.index |
Routines In this chapter routine docstrings are presented, grouped by functionality. Many docstrings contain example code, which demonstrates basic usage of the routine. The examples assume that NumPy is imported with: >>> import numpy as np
A convenient way to execute examples is the %doctest_mode mode of IPython, which allows for pasting of multi-line examples and preserves indentation.
Array creation routines From shape or value From existing data Creating record arrays (numpy.rec) Creating character arrays (numpy.char) Numerical ranges Building matrices The Matrix class
Array manipulation routines Basic operations Changing array shape Transpose-like operations Changing number of dimensions Changing kind of array Joining arrays Splitting arrays Tiling arrays Adding and removing elements Rearranging elements
Binary operations Elementwise bit operations Bit packing Output formatting
String operations String operations Comparison String information Convenience class C-Types Foreign Function Interface (numpy.ctypeslib)
Datetime Support Functions numpy.datetime_as_string numpy.datetime_data Business Day Functions
Data type routines numpy.can_cast numpy.promote_types numpy.min_scalar_type numpy.result_type numpy.common_type numpy.obj2sctype Creating data types Data type information Data type testing Miscellaneous
Optionally SciPy-accelerated routines (numpy.dual) Linear algebra FFT Other
Mathematical functions with automatic domain (numpy.emath) Functions
Floating point error handling Setting and getting error handling Internal functions
Discrete Fourier Transform (numpy.fft) Standard FFTs Real FFTs Hermitian FFTs Helper routines Background information Implementation details Type Promotion Normalization Real and Hermitian transforms Higher dimensions References Examples
Functional programming numpy.apply_along_axis numpy.apply_over_axes numpy.vectorize numpy.frompyfunc numpy.piecewise
NumPy-specific help functions Finding help Reading help
Input and output NumPy binary files (NPY, NPZ) Text files Raw binary files String formatting Memory mapping files Text formatting options Base-n representations Data sources Binary Format Description
Linear algebra (numpy.linalg) The @ operator Matrix and vector products Decompositions Matrix eigenvalues Norms and other numbers Solving equations and inverting matrices Exceptions Linear algebra on several matrices at once
Logic functions Truth value testing Array contents Array type testing Logical operations Comparison
Masked array operations Constants Creation Inspecting the array Manipulating a MaskedArray Operations on masks Conversion operations Masked arrays arithmetic
Mathematical functions Trigonometric functions Hyperbolic functions Rounding Sums, products, differences Exponents and logarithms Other special functions Floating point routines Rational routines Arithmetic operations Handling complex numbers Extrema Finding Miscellaneous
Matrix library (numpy.matlib) numpy.matlib.empty numpy.matlib.zeros numpy.matlib.ones numpy.matlib.eye numpy.matlib.identity numpy.matlib.repmat numpy.matlib.rand numpy.matlib.randn
Miscellaneous routines Performance tuning Memory ranges Array mixins NumPy version comparison Utility Matlab-like Functions Exceptions
Padding Arrays numpy.pad
Polynomials Transitioning from numpy.poly1d to numpy.polynomial Documentation for the polynomial Package Documentation for Legacy Polynomials
Random sampling (numpy.random) Quick Start Introduction Concepts Features
Set routines numpy.lib.arraysetops Making proper sets Boolean operations
Sorting, searching, and counting Sorting Searching Counting
Statistics Order statistics Averages and variances Correlating Histograms
Test Support (numpy.testing) Asserts Asserts (not recommended) Decorators Test Running Guidelines
Window functions Various windows | numpy.reference.routines |
Testing the numpy.i Typemaps Introduction Writing tests for the numpy.i SWIG interface file is a combinatorial headache. At present, 12 different data types are supported, each with 74 different argument signatures, for a total of 888 typemaps supported “out of the box”. Each of these typemaps, in turn, might require several unit tests in order to verify expected behavior for both proper and improper inputs. Currently, this results in more than 1,000 individual unit tests executed when make test is run in the numpy/tools/swig subdirectory. To facilitate this many similar unit tests, some high-level programming techniques are employed, including C and SWIG macros, as well as Python inheritance. The purpose of this document is to describe the testing infrastructure employed to verify that the numpy.i typemaps are working as expected. Testing Organization There are three independent testing frameworks supported, for one-, two-, and three-dimensional arrays respectively. For one-dimensional arrays, there are two C++ files, a header and a source, named: Vector.h
Vector.cxx
that contain prototypes and code for a variety of functions that have one-dimensional arrays as function arguments. The file: Vector.i
is a SWIG interface file that defines a python module Vector that wraps the functions in Vector.h while utilizing the typemaps in numpy.i to correctly handle the C arrays. The Makefile calls swig to generate Vector.py and Vector_wrap.cxx, and also executes the setup.py script that compiles Vector_wrap.cxx and links together the extension module _Vector.so or _Vector.dylib, depending on the platform. This extension module and the proxy file Vector.py are both placed in a subdirectory under the build directory. The actual testing takes place with a Python script named: testVector.py
that uses the standard Python library module unittest, which performs several tests of each function defined in Vector.h for each data type supported. Two-dimensional arrays are tested in exactly the same manner. The above description applies, but with Matrix substituted for Vector. For three-dimensional tests, substitute Tensor for Vector. For four-dimensional tests, substitute SuperTensor for Vector. For flat in-place array tests, substitute Flat for Vector. For the descriptions that follow, we will reference the Vector tests, but the same information applies to Matrix, Tensor and SuperTensor tests. The command make test will ensure that all of the test software is built and then run all three test scripts. Testing Header Files Vector.h is a C++ header file that defines a C macro called TEST_FUNC_PROTOS that takes two arguments: TYPE, which is a data type name such as unsigned int; and SNAME, which is a short name for the same data type with no spaces, e.g. uint. This macro defines several function prototypes that have the prefix SNAME and have at least one argument that is an array of type TYPE. Those functions that have return arguments return a TYPE value. TEST_FUNC_PROTOS is then implemented for all of the data types supported by numpy.i: signed char unsigned char short unsigned short int unsigned int long unsigned long long long unsigned long long float double Testing Source Files Vector.cxx is a C++ source file that implements compilable code for each of the function prototypes specified in Vector.h. It defines a C macro TEST_FUNCS that has the same arguments and works in the same way as TEST_FUNC_PROTOS does in Vector.h. TEST_FUNCS is implemented for each of the 12 data types as above. Testing SWIG Interface Files Vector.i is a SWIG interface file that defines python module Vector. It follows the conventions for using numpy.i as described in this chapter. It defines a SWIG macro %apply_numpy_typemaps that has a single argument TYPE. It uses the SWIG directive %apply to apply the provided typemaps to the argument signatures found in Vector.h. This macro is then implemented for all of the data types supported by numpy.i. It then does a %include "Vector.h" to wrap all of the function prototypes in Vector.h using the typemaps in numpy.i. Testing Python Scripts After make is used to build the testing extension modules, testVector.py can be run to execute the tests. As with other scripts that use unittest to facilitate unit testing, testVector.py defines a class that inherits from unittest.TestCase: class VectorTestCase(unittest.TestCase):
However, this class is not run directly. Rather, it serves as a base class to several other python classes, each one specific to a particular data type. The VectorTestCase class stores two strings for typing information: self.typeStr
A string that matches one of the SNAME prefixes used in Vector.h and Vector.cxx. For example, "double". self.typeCode
A short (typically single-character) string that represents a data type in numpy and corresponds to self.typeStr. For example, if self.typeStr is "double", then self.typeCode should be "d". Each test defined by the VectorTestCase class extracts the python function it is trying to test by accessing the Vector module’s dictionary: length = Vector.__dict__[self.typeStr + "Length"]
In the case of double precision tests, this will return the python function Vector.doubleLength. We then define a new test case class for each supported data type with a short definition such as: class doubleTestCase(VectorTestCase):
def __init__(self, methodName="runTest"):
VectorTestCase.__init__(self, methodName)
self.typeStr = "double"
self.typeCode = "d"
Each of these 12 classes is collected into a unittest.TestSuite, which is then executed. Errors and failures are summed together and returned as the exit argument. Any non-zero result indicates that at least one test did not pass. | numpy.reference.swig.testing |
setup.py #!/usr/bin/env python3
"""
Build the Cython demonstrations of low-level access to NumPy random
Usage: python setup.py build_ext -i
"""
import setuptools # triggers monkeypatching distutils
from distutils.core import setup
from os.path import dirname, join, abspath
import numpy as np
from Cython.Build import cythonize
from numpy.distutils.misc_util import get_info
from setuptools.extension import Extension
path = dirname(__file__)
src_dir = join(dirname(path), '..', 'src')
defs = [('NPY_NO_DEPRECATED_API', 0)]
inc_path = np.get_include()
lib_path = [abspath(join(np.get_include(), '..', '..', 'random', 'lib'))]
lib_path += get_info('npymath')['library_dirs']
extending = Extension("extending",
sources=[join('.', 'extending.pyx')],
include_dirs=[
np.get_include(),
join(path, '..', '..')
],
define_macros=defs,
)
distributions = Extension("extending_distributions",
sources=[join('.', 'extending_distributions.pyx')],
include_dirs=[inc_path],
library_dirs=lib_path,
libraries=['npyrandom', 'npymath'],
define_macros=defs,
)
extensions = [extending, distributions]
setup(
ext_modules=cythonize(extensions)
) | numpy.reference.random.examples.cython.setup.py |
Statistics Order statistics
ptp(a[, axis, out, keepdims]) Range of values (maximum - minimum) along an axis.
percentile(a, q[, axis, out, ...]) Compute the q-th percentile of the data along the specified axis.
nanpercentile(a, q[, axis, out, ...]) Compute the qth percentile of the data along the specified axis, while ignoring nan values.
quantile(a, q[, axis, out, overwrite_input, ...]) Compute the q-th quantile of the data along the specified axis.
nanquantile(a, q[, axis, out, ...]) Compute the qth quantile of the data along the specified axis, while ignoring nan values. Averages and variances
median(a[, axis, out, overwrite_input, keepdims]) Compute the median along the specified axis.
average(a[, axis, weights, returned]) Compute the weighted average along the specified axis.
mean(a[, axis, dtype, out, keepdims, where]) Compute the arithmetic mean along the specified axis.
std(a[, axis, dtype, out, ddof, keepdims, where]) Compute the standard deviation along the specified axis.
var(a[, axis, dtype, out, ddof, keepdims, where]) Compute the variance along the specified axis.
nanmedian(a[, axis, out, overwrite_input, ...]) Compute the median along the specified axis, while ignoring NaNs.
nanmean(a[, axis, dtype, out, keepdims, where]) Compute the arithmetic mean along the specified axis, ignoring NaNs.
nanstd(a[, axis, dtype, out, ddof, ...]) Compute the standard deviation along the specified axis, while ignoring NaNs.
nanvar(a[, axis, dtype, out, ddof, ...]) Compute the variance along the specified axis, while ignoring NaNs. Correlating
corrcoef(x[, y, rowvar, bias, ddof, dtype]) Return Pearson product-moment correlation coefficients.
correlate(a, v[, mode]) Cross-correlation of two 1-dimensional sequences.
cov(m[, y, rowvar, bias, ddof, fweights, ...]) Estimate a covariance matrix, given data and weights. Histograms
histogram(a[, bins, range, normed, weights, ...]) Compute the histogram of a dataset.
histogram2d(x, y[, bins, range, normed, ...]) Compute the bi-dimensional histogram of two data samples.
histogramdd(sample[, bins, range, normed, ...]) Compute the multidimensional histogram of some data.
bincount(x, /[, weights, minlength]) Count number of occurrences of each value in array of non-negative ints.
histogram_bin_edges(a[, bins, range, weights]) Function to calculate only the edges of the bins used by the histogram function.
digitize(x, bins[, right]) Return the indices of the bins to which each value in input array belongs. | numpy.reference.routines.statistics |
numpy.testing.assert_allclose testing.assert_allclose(actual, desired, rtol=1e-07, atol=0, equal_nan=True, err_msg='', verbose=True)[source]
Raises an AssertionError if two objects are not equal up to desired tolerance. The test is equivalent to allclose(actual, desired, rtol, atol) (note that allclose has different default values). It compares the difference between actual and desired to atol + rtol * abs(desired). New in version 1.5.0. Parameters
actualarray_like
Array obtained.
desiredarray_like
Array desired.
rtolfloat, optional
Relative tolerance.
atolfloat, optional
Absolute tolerance.
equal_nanbool, optional.
If True, NaNs will compare equal.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired are not equal up to specified precision. See also
assert_array_almost_equal_nulp, assert_array_max_ulp
Examples >>> x = [1e-5, 1e-3, 1e-1]
>>> y = np.arccos(np.cos(x))
>>> np.testing.assert_allclose(x, y, rtol=1e-5, atol=0) | numpy.reference.generated.numpy.testing.assert_allclose |
numpy.testing.assert_almost_equal testing.assert_almost_equal(actual, desired, decimal=7, err_msg='', verbose=True)[source]
Raises an AssertionError if two items are not equal up to desired precision. Note It is recommended to use one of assert_allclose, assert_array_almost_equal_nulp or assert_array_max_ulp instead of this function for more consistent floating point comparisons. The test verifies that the elements of actual and desired satisfy. abs(desired-actual) < 1.5 * 10**(-decimal) That is a looser test than originally documented, but agrees with what the actual implementation in assert_array_almost_equal did up to rounding vagaries. An exception is raised at conflicting values. For ndarrays this delegates to assert_array_almost_equal Parameters
actualarray_like
The object to check.
desiredarray_like
The expected object.
decimalint, optional
Desired precision, default is 7.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired are not equal up to specified precision. See also assert_allclose
Compare two array_like objects for equality with desired relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples >>> from numpy.testing import assert_almost_equal
>>> assert_almost_equal(2.3333333333333, 2.33333334)
>>> assert_almost_equal(2.3333333333333, 2.33333334, decimal=10)
Traceback (most recent call last):
...
AssertionError:
Arrays are not almost equal to 10 decimals
ACTUAL: 2.3333333333333
DESIRED: 2.33333334
>>> assert_almost_equal(np.array([1.0,2.3333333333333]),
... np.array([1.0,2.33333334]), decimal=9)
Traceback (most recent call last):
...
AssertionError:
Arrays are not almost equal to 9 decimals
Mismatched elements: 1 / 2 (50%)
Max absolute difference: 6.66669964e-09
Max relative difference: 2.85715698e-09
x: array([1. , 2.333333333])
y: array([1. , 2.33333334]) | numpy.reference.generated.numpy.testing.assert_almost_equal |
numpy.testing.assert_approx_equal testing.assert_approx_equal(actual, desired, significant=7, err_msg='', verbose=True)[source]
Raises an AssertionError if two items are not equal up to significant digits. Note It is recommended to use one of assert_allclose, assert_array_almost_equal_nulp or assert_array_max_ulp instead of this function for more consistent floating point comparisons. Given two numbers, check that they are approximately equal. Approximately equal is defined as the number of significant digits that agree. Parameters
actualscalar
The object to check.
desiredscalar
The expected object.
significantint, optional
Desired precision, default is 7.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired are not equal up to specified precision. See also assert_allclose
Compare two array_like objects for equality with desired relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples >>> np.testing.assert_approx_equal(0.12345677777777e-20, 0.1234567e-20)
>>> np.testing.assert_approx_equal(0.12345670e-20, 0.12345671e-20,
... significant=8)
>>> np.testing.assert_approx_equal(0.12345670e-20, 0.12345672e-20,
... significant=8)
Traceback (most recent call last):
...
AssertionError:
Items are not equal to 8 significant digits:
ACTUAL: 1.234567e-21
DESIRED: 1.2345672e-21
the evaluated condition that raises the exception is >>> abs(0.12345670e-20/1e-21 - 0.12345672e-20/1e-21) >= 10**-(8-1)
True | numpy.reference.generated.numpy.testing.assert_approx_equal |
numpy.testing.assert_array_almost_equal testing.assert_array_almost_equal(x, y, decimal=6, err_msg='', verbose=True)[source]
Raises an AssertionError if two objects are not equal up to desired precision. Note It is recommended to use one of assert_allclose, assert_array_almost_equal_nulp or assert_array_max_ulp instead of this function for more consistent floating point comparisons. The test verifies identical shapes and that the elements of actual and desired satisfy. abs(desired-actual) < 1.5 * 10**(-decimal) That is a looser test than originally documented, but agrees with what the actual implementation did up to rounding vagaries. An exception is raised at shape mismatch or conflicting values. In contrast to the standard usage in numpy, NaNs are compared like numbers, no assertion is raised if both objects have NaNs in the same positions. Parameters
xarray_like
The actual object to check.
yarray_like
The desired, expected object.
decimalint, optional
Desired precision, default is 6.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired are not equal up to specified precision. See also assert_allclose
Compare two array_like objects for equality with desired relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Examples the first assert does not raise an exception >>> np.testing.assert_array_almost_equal([1.0,2.333,np.nan],
... [1.0,2.333,np.nan])
>>> np.testing.assert_array_almost_equal([1.0,2.33333,np.nan],
... [1.0,2.33339,np.nan], decimal=5)
Traceback (most recent call last):
...
AssertionError:
Arrays are not almost equal to 5 decimals
Mismatched elements: 1 / 3 (33.3%)
Max absolute difference: 6.e-05
Max relative difference: 2.57136612e-05
x: array([1. , 2.33333, nan])
y: array([1. , 2.33339, nan])
>>> np.testing.assert_array_almost_equal([1.0,2.33333,np.nan],
... [1.0,2.33333, 5], decimal=5)
Traceback (most recent call last):
...
AssertionError:
Arrays are not almost equal to 5 decimals
x and y nan location mismatch:
x: array([1. , 2.33333, nan])
y: array([1. , 2.33333, 5. ]) | numpy.reference.generated.numpy.testing.assert_array_almost_equal |
numpy.testing.assert_array_almost_equal_nulp testing.assert_array_almost_equal_nulp(x, y, nulp=1)[source]
Compare two arrays relatively to their spacing. This is a relatively robust method to compare two arrays whose amplitude is variable. Parameters
x, yarray_like
Input arrays.
nulpint, optional
The maximum number of unit in the last place for tolerance (see Notes). Default is 1. Returns
None
Raises
AssertionError
If the spacing between x and y for one or more elements is larger than nulp. See also assert_array_max_ulp
Check that all items of arrays differ in at most N Units in the Last Place. spacing
Return the distance between x and the nearest adjacent number. Notes An assertion is raised if the following condition is not met: abs(x - y) <= nulps * spacing(maximum(abs(x), abs(y)))
Examples >>> x = np.array([1., 1e-10, 1e-20])
>>> eps = np.finfo(x.dtype).eps
>>> np.testing.assert_array_almost_equal_nulp(x, x*eps/2 + x)
>>> np.testing.assert_array_almost_equal_nulp(x, x*eps + x)
Traceback (most recent call last):
...
AssertionError: X and Y are not equal to 1 ULP (max is 2) | numpy.reference.generated.numpy.testing.assert_array_almost_equal_nulp |
numpy.testing.assert_array_equal testing.assert_array_equal(x, y, err_msg='', verbose=True)[source]
Raises an AssertionError if two array_like objects are not equal. Given two array_like objects, check that the shape is equal and all elements of these objects are equal (but see the Notes for the special handling of a scalar). An exception is raised at shape mismatch or conflicting values. In contrast to the standard usage in numpy, NaNs are compared like numbers, no assertion is raised if both objects have NaNs in the same positions. The usual caution for verifying equality with floating point numbers is advised. Parameters
xarray_like
The actual object to check.
yarray_like
The desired, expected object.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired objects are not equal. See also assert_allclose
Compare two array_like objects for equality with desired relative and/or absolute precision.
assert_array_almost_equal_nulp, assert_array_max_ulp, assert_equal
Notes When one of x and y is a scalar and the other is array_like, the function checks that each element of the array_like object is equal to the scalar. Examples The first assert does not raise an exception: >>> np.testing.assert_array_equal([1.0,2.33333,np.nan],
... [np.exp(0),2.33333, np.nan])
Assert fails with numerical imprecision with floats: >>> np.testing.assert_array_equal([1.0,np.pi,np.nan],
... [1, np.sqrt(np.pi)**2, np.nan])
Traceback (most recent call last):
...
AssertionError:
Arrays are not equal
Mismatched elements: 1 / 3 (33.3%)
Max absolute difference: 4.4408921e-16
Max relative difference: 1.41357986e-16
x: array([1. , 3.141593, nan])
y: array([1. , 3.141593, nan])
Use assert_allclose or one of the nulp (number of floating point values) functions for these cases instead: >>> np.testing.assert_allclose([1.0,np.pi,np.nan],
... [1, np.sqrt(np.pi)**2, np.nan],
... rtol=1e-10, atol=0)
As mentioned in the Notes section, assert_array_equal has special handling for scalars. Here the test checks that each value in x is 3: >>> x = np.full((2, 5), fill_value=3)
>>> np.testing.assert_array_equal(x, 3) | numpy.reference.generated.numpy.testing.assert_array_equal |
numpy.testing.assert_array_less testing.assert_array_less(x, y, err_msg='', verbose=True)[source]
Raises an AssertionError if two array_like objects are not ordered by less than. Given two array_like objects, check that the shape is equal and all elements of the first object are strictly smaller than those of the second object. An exception is raised at shape mismatch or incorrectly ordered values. Shape mismatch does not raise if an object has zero dimension. In contrast to the standard usage in numpy, NaNs are compared, no assertion is raised if both objects have NaNs in the same positions. Parameters
xarray_like
The smaller object to check.
yarray_like
The larger object to compare.
err_msgstring
The error message to be printed in case of failure.
verbosebool
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired objects are not equal. See also assert_array_equal
tests objects for equality assert_array_almost_equal
test objects for equality up to precision Examples >>> np.testing.assert_array_less([1.0, 1.0, np.nan], [1.1, 2.0, np.nan])
>>> np.testing.assert_array_less([1.0, 1.0, np.nan], [1, 2.0, np.nan])
Traceback (most recent call last):
...
AssertionError:
Arrays are not less-ordered
Mismatched elements: 1 / 3 (33.3%)
Max absolute difference: 1.
Max relative difference: 0.5
x: array([ 1., 1., nan])
y: array([ 1., 2., nan])
>>> np.testing.assert_array_less([1.0, 4.0], 3)
Traceback (most recent call last):
...
AssertionError:
Arrays are not less-ordered
Mismatched elements: 1 / 2 (50%)
Max absolute difference: 2.
Max relative difference: 0.66666667
x: array([1., 4.])
y: array(3)
>>> np.testing.assert_array_less([1.0, 2.0, 3.0], [4])
Traceback (most recent call last):
...
AssertionError:
Arrays are not less-ordered
(shapes (3,), (1,) mismatch)
x: array([1., 2., 3.])
y: array([4]) | numpy.reference.generated.numpy.testing.assert_array_less |
numpy.testing.assert_array_max_ulp testing.assert_array_max_ulp(a, b, maxulp=1, dtype=None)[source]
Check that all items of arrays differ in at most N Units in the Last Place. Parameters
a, barray_like
Input arrays to be compared.
maxulpint, optional
The maximum number of units in the last place that elements of a and b can differ. Default is 1.
dtypedtype, optional
Data-type to convert a and b to if given. Default is None. Returns
retndarray
Array containing number of representable floating point numbers between items in a and b. Raises
AssertionError
If one or more elements differ by more than maxulp. See also assert_array_almost_equal_nulp
Compare two arrays relatively to their spacing. Notes For computing the ULP difference, this API does not differentiate between various representations of NAN (ULP difference between 0x7fc00000 and 0xffc00000 is zero). Examples >>> a = np.linspace(0., 1., 100)
>>> res = np.testing.assert_array_max_ulp(a, np.arcsin(np.sin(a))) | numpy.reference.generated.numpy.testing.assert_array_max_ulp |
numpy.testing.assert_equal testing.assert_equal(actual, desired, err_msg='', verbose=True)[source]
Raises an AssertionError if two objects are not equal. Given two objects (scalars, lists, tuples, dictionaries or numpy arrays), check that all elements of these objects are equal. An exception is raised at the first conflicting values. When one of actual and desired is a scalar and the other is array_like, the function checks that each element of the array_like object is equal to the scalar. This function handles NaN comparisons as if NaN was a “normal” number. That is, AssertionError is not raised if both objects have NaNs in the same positions. This is in contrast to the IEEE standard on NaNs, which says that NaN compared to anything must return False. Parameters
actualarray_like
The object to check.
desiredarray_like
The expected object.
err_msgstr, optional
The error message to be printed in case of failure.
verbosebool, optional
If True, the conflicting values are appended to the error message. Raises
AssertionError
If actual and desired are not equal. Examples >>> np.testing.assert_equal([4,5], [4,6])
Traceback (most recent call last):
...
AssertionError:
Items are not equal:
item=1
ACTUAL: 5
DESIRED: 6
The following comparison does not raise an exception. There are NaNs in the inputs, but they are in the same positions. >>> np.testing.assert_equal(np.array([1.0, 2.0, np.nan]), [1, 2, np.nan]) | numpy.reference.generated.numpy.testing.assert_equal |
numpy.testing.assert_raises testing.assert_raises(exception_class, callable, *args, **kwargs) assert_raises(exception_class)[source]
testing.assert_raises(exception_class) → None
Fail unless an exception of class exception_class is thrown by callable when invoked with arguments args and keyword arguments kwargs. If a different type of exception is thrown, it will not be caught, and the test case will be deemed to have suffered an error, exactly as for an unexpected exception. Alternatively, assert_raises can be used as a context manager: >>> from numpy.testing import assert_raises
>>> with assert_raises(ZeroDivisionError):
... 1 / 0
is equivalent to >>> def div(x, y):
... return x / y
>>> assert_raises(ZeroDivisionError, div, 1, 0) | numpy.reference.generated.numpy.testing.assert_raises |
numpy.testing.assert_raises_regex testing.assert_raises_regex(exception_class, expected_regexp, callable, *args, **kwargs) assert_raises_regex(exception_class, expected_regexp)[source]
Fail unless an exception of class exception_class and with message that matches expected_regexp is thrown by callable when invoked with arguments args and keyword arguments kwargs. Alternatively, can be used as a context manager like assert_raises. Name of this function adheres to Python 3.2+ reference, but should work in all versions down to 2.6. Notes New in version 1.9.0. | numpy.reference.generated.numpy.testing.assert_raises_regex |
numpy.testing.assert_string_equal testing.assert_string_equal(actual, desired)[source]
Test if two strings are equal. If the given strings are equal, assert_string_equal does nothing. If they are not equal, an AssertionError is raised, and the diff between the strings is shown. Parameters
actualstr
The string to test for equality against the expected string.
desiredstr
The expected string. Examples >>> np.testing.assert_string_equal('abc', 'abc')
>>> np.testing.assert_string_equal('abc', 'abcd')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
...
AssertionError: Differences in strings:
- abc+ abcd? + | numpy.reference.generated.numpy.testing.assert_string_equal |
numpy.testing.assert_warns testing.assert_warns(warning_class, *args, **kwargs)[source]
Fail unless the given callable throws the specified warning. A warning of class warning_class should be thrown by the callable when invoked with arguments args and keyword arguments kwargs. If a different type of warning is thrown, it will not be caught. If called with all arguments other than the warning class omitted, may be used as a context manager: with assert_warns(SomeWarning):
do_something() The ability to be used as a context manager is new in NumPy v1.11.0. New in version 1.4.0. Parameters
warning_classclass
The class defining the warning that func is expected to throw.
funccallable, optional
Callable to test
*argsArguments
Arguments for func.
**kwargsKwargs
Keyword arguments for func. Returns
The value returned by func.
Examples >>> import warnings
>>> def deprecated_func(num):
... warnings.warn("Please upgrade", DeprecationWarning)
... return num*num
>>> with np.testing.assert_warns(DeprecationWarning):
... assert deprecated_func(4) == 16
>>> # or passing a func
>>> ret = np.testing.assert_warns(DeprecationWarning, deprecated_func, 4)
>>> assert ret == 16 | numpy.reference.generated.numpy.testing.assert_warns |
numpy.testing.dec.deprecated testing.dec.deprecated(conditional=True)[source]
Deprecated since version 1.21: This decorator is retained for compatibility with the nose testing framework, which is being phased out. Please use the nose2 or pytest frameworks instead. Filter deprecation warnings while running the test suite. This decorator can be used to filter DeprecationWarning’s, to avoid printing them during the test suite run, while checking that the test actually raises a DeprecationWarning. Parameters
conditionalbool or callable, optional
Flag to determine whether to mark test as deprecated or not. If the condition is a callable, it is used at runtime to dynamically make the decision. Default is True. Returns
decoratorfunction
The deprecated decorator itself. Notes New in version 1.4.0. | numpy.reference.generated.numpy.testing.dec.deprecated |
numpy.testing.dec.knownfailureif testing.dec.knownfailureif(fail_condition, msg=None)[source]
Deprecated since version 1.21: This decorator is retained for compatibility with the nose testing framework, which is being phased out. Please use the nose2 or pytest frameworks instead. Make function raise KnownFailureException exception if given condition is true. If the condition is a callable, it is used at runtime to dynamically make the decision. This is useful for tests that may require costly imports, to delay the cost until the test suite is actually executed. Parameters
fail_conditionbool or callable
Flag to determine whether to mark the decorated test as a known failure (if True) or not (if False).
msgstr, optional
Message to give on raising a KnownFailureException exception. Default is None. Returns
decoratorfunction
Decorator, which, when applied to a function, causes KnownFailureException to be raised when fail_condition is True, and the function to be called normally otherwise. Notes The decorator itself is decorated with the nose.tools.make_decorator function in order to transmit function name, and various other metadata. | numpy.reference.generated.numpy.testing.dec.knownfailureif |
numpy.testing.dec.setastest testing.dec.setastest(tf=True)[source]
Deprecated since version 1.21: This decorator is retained for compatibility with the nose testing framework, which is being phased out. Please use the nose2 or pytest frameworks instead. Signals to nose that this function is or is not a test. Parameters
tfbool
If True, specifies that the decorated callable is a test. If False, specifies that the decorated callable is not a test. Default is True. Notes This decorator can’t use the nose namespace, because it can be called from a non-test module. See also istest and nottest in nose.tools. Examples setastest can be used in the following way: from numpy.testing import dec
@dec.setastest(False)
def func_with_test_in_name(arg1, arg2):
pass | numpy.reference.generated.numpy.testing.dec.setastest |
numpy.testing.dec.skipif testing.dec.skipif(skip_condition, msg=None)[source]
Deprecated since version 1.21: This decorator is retained for compatibility with the nose testing framework, which is being phased out. Please use the nose2 or pytest frameworks instead. Make function raise SkipTest exception if a given condition is true. If the condition is a callable, it is used at runtime to dynamically make the decision. This is useful for tests that may require costly imports, to delay the cost until the test suite is actually executed. Parameters
skip_conditionbool or callable
Flag to determine whether to skip the decorated test.
msgstr, optional
Message to give on raising a SkipTest exception. Default is None. Returns
decoratorfunction
Decorator which, when applied to a function, causes SkipTest to be raised when skip_condition is True, and the function to be called normally otherwise. Notes The decorator itself is decorated with the nose.tools.make_decorator function in order to transmit function name, and various other metadata. | numpy.reference.generated.numpy.testing.dec.skipif |
numpy.testing.dec.slow testing.dec.slow(t)[source]
Deprecated since version 1.21: This decorator is retained for compatibility with the nose testing framework, which is being phased out. Please use the nose2 or pytest frameworks instead. Label a test as ‘slow’. The exact definition of a slow test is obviously both subjective and hardware-dependent, but in general any individual test that requires more than a second or two should be labeled as slow (the whole suite consists of thousands of tests, so even a second is significant). Parameters
tcallable
The test to label as slow. Returns
tcallable
The decorated test t. Examples The numpy.testing module includes import decorators as dec. A test can be decorated as slow like this: from numpy.testing import *
@dec.slow
def test_big(self):
print('Big, slow test') | numpy.reference.generated.numpy.testing.dec.slow |
numpy.testing.decorate_methods testing.decorate_methods(cls, decorator, testmatch=None)[source]
Apply a decorator to all methods in a class matching a regular expression. The given decorator is applied to all public methods of cls that are matched by the regular expression testmatch (testmatch.search(methodname)). Methods that are private, i.e. start with an underscore, are ignored. Parameters
clsclass
Class whose methods to decorate.
decoratorfunction
Decorator to apply to methods
testmatchcompiled regexp or str, optional
The regular expression. Default value is None, in which case the nose default (re.compile(r'(?:^|[\b_\.%s-])[Tt]est' % os.sep)) is used. If testmatch is a string, it is compiled to a regular expression first. | numpy.reference.generated.numpy.testing.decorate_methods |
numpy.testing.run_module_suite testing.run_module_suite(file_to_run=None, argv=None)[source]
Run a test module. Equivalent to calling $ nosetests <argv> <file_to_run> from the command line Parameters
file_to_runstr, optional
Path to test module, or None. By default, run the module from which this function is called.
argvlist of strings
Arguments to be passed to the nose test runner. argv[0] is ignored. All command line arguments accepted by nosetests will work. If it is the default value None, sys.argv is used. New in version 1.9.0. Examples Adding the following: if __name__ == "__main__" :
run_module_suite(argv=sys.argv)
at the end of a test module will run the tests when that module is called in the python interpreter. Alternatively, calling: >>> run_module_suite(file_to_run="numpy/tests/test_matlib.py")
from an interpreter will run all the test routine in ‘test_matlib.py’. | numpy.reference.generated.numpy.testing.run_module_suite |
numpy.testing.rundocs testing.rundocs(filename=None, raise_on_error=True)[source]
Run doctests found in the given file. By default rundocs raises an AssertionError on failure. Parameters
filenamestr
The path to the file for which the doctests are run.
raise_on_errorbool
Whether to raise an AssertionError when a doctest fails. Default is True. Notes The doctests can be run by the user/developer by adding the doctests argument to the test() call. For example, to run all tests (including doctests) for numpy.lib: >>> np.lib.test(doctests=True) | numpy.reference.generated.numpy.testing.rundocs |
numpy.testing.suppress_warnings.__call__ method testing.suppress_warnings.__call__(func)[source]
Function decorator to apply certain suppressions to a whole function. | numpy.reference.generated.numpy.testing.suppress_warnings.__call__ |
numpy.testing.suppress_warnings.filter method testing.suppress_warnings.filter(category=<class 'Warning'>, message='', module=None)[source]
Add a new suppressing filter or apply it if the state is entered. Parameters
categoryclass, optional
Warning class to filter
messagestring, optional
Regular expression matching the warning message.
modulemodule, optional
Module to filter for. Note that the module (and its file) must match exactly and cannot be a submodule. This may make it unreliable for external modules. Notes When added within a context, filters are only added inside the context and will be forgotten when the context is exited. | numpy.reference.generated.numpy.testing.suppress_warnings.filter |
numpy.testing.suppress_warnings.record method testing.suppress_warnings.record(category=<class 'Warning'>, message='', module=None)[source]
Append a new recording filter or apply it if the state is entered. All warnings matching will be appended to the log attribute. Parameters
categoryclass, optional
Warning class to filter
messagestring, optional
Regular expression matching the warning message.
modulemodule, optional
Module to filter for. Note that the module (and its file) must match exactly and cannot be a submodule. This may make it unreliable for external modules. Returns
loglist
A list which will be filled with all matched warnings. Notes When added within a context, filters are only added inside the context and will be forgotten when the context is exited. | numpy.reference.generated.numpy.testing.suppress_warnings.record |
numpy.ufunc.__call__ method ufunc.__call__(*args, **kwargs)
Call self as a function. | numpy.reference.generated.numpy.ufunc.__call__ |
numpy.ufunc.accumulate method ufunc.accumulate(array, axis=0, dtype=None, out=None)
Accumulate the result of applying the operator to all elements. For a one-dimensional array, accumulate produces results equivalent to: r = np.empty(len(A))
t = op.identity # op = the ufunc being applied to A's elements
for i in range(len(A)):
t = op(t, A[i])
r[i] = t
return r
For example, add.accumulate() is equivalent to np.cumsum(). For a multi-dimensional array, accumulate is applied along only one axis (axis zero by default; see Examples below) so repeated use is necessary if one wants to accumulate over multiple axes. Parameters
arrayarray_like
The array to act on.
axisint, optional
The axis along which to apply the accumulation; default is zero.
dtypedata-type code, optional
The data-type used to represent the intermediate results. Defaults to the data-type of the output array if such is provided, or the the data-type of the input array if no output array is provided.
outndarray, None, or tuple of ndarray and None, optional
A location into which the result is stored. If not provided or None, a freshly-allocated array is returned. For consistency with ufunc.__call__, if given as a keyword, this may be wrapped in a 1-element tuple. Changed in version 1.13.0: Tuples are allowed for keyword argument. Returns
rndarray
The accumulated values. If out was supplied, r is a reference to out. Examples 1-D array examples: >>> np.add.accumulate([2, 3, 5])
array([ 2, 5, 10])
>>> np.multiply.accumulate([2, 3, 5])
array([ 2, 6, 30])
2-D array examples: >>> I = np.eye(2)
>>> I
array([[1., 0.],
[0., 1.]])
Accumulate along axis 0 (rows), down columns: >>> np.add.accumulate(I, 0)
array([[1., 0.],
[1., 1.]])
>>> np.add.accumulate(I) # no axis specified = axis zero
array([[1., 0.],
[1., 1.]])
Accumulate along axis 1 (columns), through rows: >>> np.add.accumulate(I, 1)
array([[1., 1.],
[0., 1.]]) | numpy.reference.generated.numpy.ufunc.accumulate |
numpy.ufunc.at method ufunc.at(a, indices, b=None, /)
Performs unbuffered in place operation on operand ‘a’ for elements specified by ‘indices’. For addition ufunc, this method is equivalent to a[indices] += b, except that results are accumulated for elements that are indexed more than once. For example, a[[0,0]] += 1 will only increment the first element once because of buffering, whereas add.at(a, [0,0], 1) will increment the first element twice. New in version 1.8.0. Parameters
aarray_like
The array to perform in place operation on.
indicesarray_like or tuple
Array like index object or slice object for indexing into first operand. If first operand has multiple dimensions, indices can be a tuple of array like index objects or slice objects.
barray_like
Second operand for ufuncs requiring two operands. Operand must be broadcastable over first operand after indexing or slicing. Examples Set items 0 and 1 to their negative values: >>> a = np.array([1, 2, 3, 4])
>>> np.negative.at(a, [0, 1])
>>> a
array([-1, -2, 3, 4])
Increment items 0 and 1, and increment item 2 twice: >>> a = np.array([1, 2, 3, 4])
>>> np.add.at(a, [0, 1, 2, 2], 1)
>>> a
array([2, 3, 5, 4])
Add items 0 and 1 in first array to second array, and store results in first array: >>> a = np.array([1, 2, 3, 4])
>>> b = np.array([1, 2])
>>> np.add.at(a, [0, 1], b)
>>> a
array([2, 4, 3, 4]) | numpy.reference.generated.numpy.ufunc.at |
numpy.ufunc.identity attribute ufunc.identity
The identity value. Data attribute containing the identity element for the ufunc, if it has one. If it does not, the attribute value is None. Examples >>> np.add.identity
0
>>> np.multiply.identity
1
>>> np.power.identity
1
>>> print(np.exp.identity)
None | numpy.reference.generated.numpy.ufunc.identity |
numpy.ufunc.nargs attribute ufunc.nargs
The number of arguments. Data attribute containing the number of arguments the ufunc takes, including optional ones. Notes Typically this value will be one more than what you might expect because all ufuncs take the optional “out” argument. Examples >>> np.add.nargs
3
>>> np.multiply.nargs
3
>>> np.power.nargs
3
>>> np.exp.nargs
2 | numpy.reference.generated.numpy.ufunc.nargs |
numpy.ufunc.nin attribute ufunc.nin
The number of inputs. Data attribute containing the number of arguments the ufunc treats as input. Examples >>> np.add.nin
2
>>> np.multiply.nin
2
>>> np.power.nin
2
>>> np.exp.nin
1 | numpy.reference.generated.numpy.ufunc.nin |
numpy.ufunc.nout attribute ufunc.nout
The number of outputs. Data attribute containing the number of arguments the ufunc treats as output. Notes Since all ufuncs can take output arguments, this will always be (at least) 1. Examples >>> np.add.nout
1
>>> np.multiply.nout
1
>>> np.power.nout
1
>>> np.exp.nout
1 | numpy.reference.generated.numpy.ufunc.nout |
numpy.ufunc.ntypes attribute ufunc.ntypes
The number of types. The number of numerical NumPy types - of which there are 18 total - on which the ufunc can operate. See also numpy.ufunc.types
Examples >>> np.add.ntypes
18
>>> np.multiply.ntypes
18
>>> np.power.ntypes
17
>>> np.exp.ntypes
7
>>> np.remainder.ntypes
14 | numpy.reference.generated.numpy.ufunc.ntypes |
numpy.ufunc.outer method ufunc.outer(A, B, /, **kwargs)
Apply the ufunc op to all pairs (a, b) with a in A and b in B. Let M = A.ndim, N = B.ndim. Then the result, C, of op.outer(A, B) is an array of dimension M + N such that: \[C[i_0, ..., i_{M-1}, j_0, ..., j_{N-1}] = op(A[i_0, ..., i_{M-1}], B[j_0, ..., j_{N-1}])\] For A and B one-dimensional, this is equivalent to: r = empty(len(A),len(B))
for i in range(len(A)):
for j in range(len(B)):
r[i,j] = op(A[i], B[j]) # op = ufunc in question
Parameters
Aarray_like
First array
Barray_like
Second array
kwargsany
Arguments to pass on to the ufunc. Typically dtype or out. See ufunc for a comprehensive overview of all available arguments. Returns
rndarray
Output array See also numpy.outer
A less powerful version of np.multiply.outer that ravels all inputs to 1D. This exists primarily for compatibility with old code. tensordot
np.tensordot(a, b, axes=((), ())) and np.multiply.outer(a, b) behave same for all dimensions of a and b. Examples >>> np.multiply.outer([1, 2, 3], [4, 5, 6])
array([[ 4, 5, 6],
[ 8, 10, 12],
[12, 15, 18]])
A multi-dimensional example: >>> A = np.array([[1, 2, 3], [4, 5, 6]])
>>> A.shape
(2, 3)
>>> B = np.array([[1, 2, 3, 4]])
>>> B.shape
(1, 4)
>>> C = np.multiply.outer(A, B)
>>> C.shape; C
(2, 3, 1, 4)
array([[[[ 1, 2, 3, 4]],
[[ 2, 4, 6, 8]],
[[ 3, 6, 9, 12]]],
[[[ 4, 8, 12, 16]],
[[ 5, 10, 15, 20]],
[[ 6, 12, 18, 24]]]]) | numpy.reference.generated.numpy.ufunc.outer |
numpy.ufunc.reduce method ufunc.reduce(array, axis=0, dtype=None, out=None, keepdims=False, initial=<no value>, where=True)
Reduces array’s dimension by one, by applying ufunc along one axis. Let \(array.shape = (N_0, ..., N_i, ..., N_{M-1})\). Then \(ufunc.reduce(array, axis=i)[k_0, ..,k_{i-1}, k_{i+1}, .., k_{M-1}]\) = the result of iterating j over \(range(N_i)\), cumulatively applying ufunc to each \(array[k_0, ..,k_{i-1}, j, k_{i+1}, .., k_{M-1}]\). For a one-dimensional array, reduce produces results equivalent to: r = op.identity # op = ufunc
for i in range(len(A)):
r = op(r, A[i])
return r
For example, add.reduce() is equivalent to sum(). Parameters
arrayarray_like
The array to act on.
axisNone or int or tuple of ints, optional
Axis or axes along which a reduction is performed. The default (axis = 0) is perform a reduction over the first dimension of the input array. axis may be negative, in which case it counts from the last to the first axis. New in version 1.7.0. If this is None, a reduction is performed over all the axes. If this is a tuple of ints, a reduction is performed on multiple axes, instead of a single axis or all the axes as before. For operations which are either not commutative or not associative, doing a reduction over multiple axes is not well-defined. The ufuncs do not currently raise an exception in this case, but will likely do so in the future.
dtypedata-type code, optional
The type used to represent the intermediate results. Defaults to the data-type of the output array if this is provided, or the data-type of the input array if no output array is provided.
outndarray, None, or tuple of ndarray and None, optional
A location into which the result is stored. If not provided or None, a freshly-allocated array is returned. For consistency with ufunc.__call__, if given as a keyword, this may be wrapped in a 1-element tuple. Changed in version 1.13.0: Tuples are allowed for keyword argument.
keepdimsbool, optional
If this is set to True, the axes which are reduced are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the original array. New in version 1.7.0.
initialscalar, optional
The value with which to start the reduction. If the ufunc has no identity or the dtype is object, this defaults to None - otherwise it defaults to ufunc.identity. If None is given, the first element of the reduction is used, and an error is thrown if the reduction is empty. New in version 1.15.0.
wherearray_like of bool, optional
A boolean array which is broadcasted to match the dimensions of array, and selects elements to include in the reduction. Note that for ufuncs like minimum that do not have an identity defined, one has to pass in also initial. New in version 1.17.0. Returns
rndarray
The reduced array. If out was supplied, r is a reference to it. Examples >>> np.multiply.reduce([2,3,5])
30
A multi-dimensional array example: >>> X = np.arange(8).reshape((2,2,2))
>>> X
array([[[0, 1],
[2, 3]],
[[4, 5],
[6, 7]]])
>>> np.add.reduce(X, 0)
array([[ 4, 6],
[ 8, 10]])
>>> np.add.reduce(X) # confirm: default axis value is 0
array([[ 4, 6],
[ 8, 10]])
>>> np.add.reduce(X, 1)
array([[ 2, 4],
[10, 12]])
>>> np.add.reduce(X, 2)
array([[ 1, 5],
[ 9, 13]])
You can use the initial keyword argument to initialize the reduction with a different value, and where to select specific elements to include: >>> np.add.reduce([10], initial=5)
15
>>> np.add.reduce(np.ones((2, 2, 2)), axis=(0, 2), initial=10)
array([14., 14.])
>>> a = np.array([10., np.nan, 10])
>>> np.add.reduce(a, where=~np.isnan(a))
20.0
Allows reductions of empty arrays where they would normally fail, i.e. for ufuncs without an identity. >>> np.minimum.reduce([], initial=np.inf)
inf
>>> np.minimum.reduce([[1., 2.], [3., 4.]], initial=10., where=[True, False])
array([ 1., 10.])
>>> np.minimum.reduce([])
Traceback (most recent call last):
...
ValueError: zero-size array to reduction operation minimum which has no identity | numpy.reference.generated.numpy.ufunc.reduce |
numpy.ufunc.reduceat method ufunc.reduceat(array, indices, axis=0, dtype=None, out=None)
Performs a (local) reduce with specified slices over a single axis. For i in range(len(indices)), reduceat computes ufunc.reduce(array[indices[i]:indices[i+1]]), which becomes the i-th generalized “row” parallel to axis in the final result (i.e., in a 2-D array, for example, if axis = 0, it becomes the i-th row, but if axis = 1, it becomes the i-th column). There are three exceptions to this: when i = len(indices) - 1 (so for the last index), indices[i+1] = array.shape[axis]. if indices[i] >= indices[i + 1], the i-th generalized “row” is simply array[indices[i]]. if indices[i] >= len(array) or indices[i] < 0, an error is raised. The shape of the output depends on the size of indices, and may be larger than array (this happens if len(indices) > array.shape[axis]). Parameters
arrayarray_like
The array to act on.
indicesarray_like
Paired indices, comma separated (not colon), specifying slices to reduce.
axisint, optional
The axis along which to apply the reduceat.
dtypedata-type code, optional
The type used to represent the intermediate results. Defaults to the data type of the output array if this is provided, or the data type of the input array if no output array is provided.
outndarray, None, or tuple of ndarray and None, optional
A location into which the result is stored. If not provided or None, a freshly-allocated array is returned. For consistency with ufunc.__call__, if given as a keyword, this may be wrapped in a 1-element tuple. Changed in version 1.13.0: Tuples are allowed for keyword argument. Returns
rndarray
The reduced values. If out was supplied, r is a reference to out. Notes A descriptive example: If array is 1-D, the function ufunc.accumulate(array) is the same as ufunc.reduceat(array, indices)[::2] where indices is range(len(array) - 1) with a zero placed in every other element: indices = zeros(2 * len(array) - 1), indices[1::2] = range(1, len(array)). Don’t be fooled by this attribute’s name: reduceat(array) is not necessarily smaller than array. Examples To take the running sum of four successive values: >>> np.add.reduceat(np.arange(8),[0,4, 1,5, 2,6, 3,7])[::2]
array([ 6, 10, 14, 18])
A 2-D example: >>> x = np.linspace(0, 15, 16).reshape(4,4)
>>> x
array([[ 0., 1., 2., 3.],
[ 4., 5., 6., 7.],
[ 8., 9., 10., 11.],
[12., 13., 14., 15.]])
# reduce such that the result has the following five rows:
# [row1 + row2 + row3]
# [row4]
# [row2]
# [row3]
# [row1 + row2 + row3 + row4]
>>> np.add.reduceat(x, [0, 3, 1, 2, 0])
array([[12., 15., 18., 21.],
[12., 13., 14., 15.],
[ 4., 5., 6., 7.],
[ 8., 9., 10., 11.],
[24., 28., 32., 36.]])
# reduce such that result has the following two columns:
# [col1 * col2 * col3, col4]
>>> np.multiply.reduceat(x, [0, 3], 1)
array([[ 0., 3.],
[ 120., 7.],
[ 720., 11.],
[2184., 15.]]) | numpy.reference.generated.numpy.ufunc.reduceat |
numpy.ufunc.signature attribute ufunc.signature
Definition of the core elements a generalized ufunc operates on. The signature determines how the dimensions of each input/output array are split into core and loop dimensions: Each dimension in the signature is matched to a dimension of the corresponding passed-in array, starting from the end of the shape tuple. Core dimensions assigned to the same label in the signature must have exactly matching sizes, no broadcasting is performed. The core dimensions are removed from all inputs and the remaining dimensions are broadcast together, defining the loop dimensions. Notes Generalized ufuncs are used internally in many linalg functions, and in the testing suite; the examples below are taken from these. For ufuncs that operate on scalars, the signature is None, which is equivalent to ‘()’ for every argument. Examples >>> np.core.umath_tests.matrix_multiply.signature
'(m,n),(n,p)->(m,p)'
>>> np.linalg._umath_linalg.det.signature
'(m,m)->()'
>>> np.add.signature is None
True # equivalent to '(),()->()' | numpy.reference.generated.numpy.ufunc.signature |
numpy.ufunc.types attribute ufunc.types
Returns a list with types grouped input->output. Data attribute listing the data-type “Domain-Range” groupings the ufunc can deliver. The data-types are given using the character codes. See also numpy.ufunc.ntypes
Examples >>> np.add.types
['??->?', 'bb->b', 'BB->B', 'hh->h', 'HH->H', 'ii->i', 'II->I', 'll->l',
'LL->L', 'qq->q', 'QQ->Q', 'ff->f', 'dd->d', 'gg->g', 'FF->F', 'DD->D',
'GG->G', 'OO->O']
>>> np.multiply.types
['??->?', 'bb->b', 'BB->B', 'hh->h', 'HH->H', 'ii->i', 'II->I', 'll->l',
'LL->L', 'qq->q', 'QQ->Q', 'ff->f', 'dd->d', 'gg->g', 'FF->F', 'DD->D',
'GG->G', 'OO->O']
>>> np.power.types
['bb->b', 'BB->B', 'hh->h', 'HH->H', 'ii->i', 'II->I', 'll->l', 'LL->L',
'qq->q', 'QQ->Q', 'ff->f', 'dd->d', 'gg->g', 'FF->F', 'DD->D', 'GG->G',
'OO->O']
>>> np.exp.types
['f->f', 'd->d', 'g->g', 'F->F', 'D->D', 'G->G', 'O->O']
>>> np.remainder.types
['bb->b', 'BB->B', 'hh->h', 'HH->H', 'ii->i', 'II->I', 'll->l', 'LL->L',
'qq->q', 'QQ->Q', 'ff->f', 'dd->d', 'gg->g', 'OO->O'] | numpy.reference.generated.numpy.ufunc.types |