HDTenEightyP/NetNews huggingface dataset:
From: gaehler@sc2a.unige.ch
Subject: Bug in MAPLE group theory package
Organization: University of Geneva, Switzerland
Date: Tue, 17 Nov 1992 15:21:50 GMT

I have found a bug in the group theory package of MAPLE. I first define
a group by a set of generators and relations - it's the icosahedral group
of order 60 (just rotations). I then calculate the order of a subgroup
generated by a word in the generators, with a strange result:

    |\^/|      MAPLE V
._|\|   |/|_.  Copyright (c) 1981-1990 by the University of Waterloo.
 \  MAPLE  /   All rights reserved.  MAPLE is a registered trademark of
 <____ ____>   Waterloo Maple Software.
      |        Type ? for help.
> with(group):
> gr := grelgroup({a, b}, {[a, a, a, a, a], [b, b, b], [a, b, a, b]});

      gr := grelgroup({a, b}, {[a, a, a, a, a], [b, b, b], [a, b, a, b]})

> grouporder(pres(subgrel({x=[a, a]}, gr)));

                                       15 

And I thought the icosahedral group would have only elements of order
1, 2, 3 and 5! From the relations it clearly follows that a generates
a cyclic subgroup of order 5. The element x=[a,a] should therefore
generate the same subgroup. MAPLE, however, believes that x generates
a cyclic subgroup of order 15:

> pres(subgrel({x=[a, a]}, gr));

        grelgroup({x}, {[x, x, x, x, x, x, x, x, x, x, x, x, x, x, x]})

MAPLE finds, by the way, also elements or order 6 :-)
As I have only very little experience with MAPLE, it is not excluded 
that I misunderstood something. Has anyone else made bad experience
with the MAPLE group theory package?

                                          Franz Gaehler
                                          Theoretical Physics
                                          University of Geneva
                                          gaehler@sc2a.unige.ch
From: fateman@peoplesparc.Berkeley.EDU (Richard Fateman)
Newsgroups: sci.math.symbolic
Subject: Serious Programming (was: Re: MAPLE resources reccomendation)
Date: 17 Nov 1992 17:02:28 GMT
Organization: University of California, Berkeley
NNTP-Posting-Host: peoplesparc.berkeley.edu

In article <BxuxC6.Dxz@news.cso.uiuc.edu> Richard J. Gaylord <gaylord@ux1.cso.uiuc.edu> writes:

>
>the basic question iswhat do you want out of your cas? if you are going
>to do serious programming,  mathematica  is totally in front of the
>others.

I think that if you are doing serious programming, the mandatory use of
Mathematica's built-in interpreted user language is a serious handicap
for many purposes.  It's ok for fiddling around, but if it were really
good, then there wouldn't be 400,000 (or more) lines of C in the
system.  Most add-ons written in the Mathematica language have
serious efficiency problems, and some are outright crocks that break
when stressed.

While I am not a fan of the Maple syntax, it is certainly
possible to write serious programs in it, as demonstrated by the Maple
group's having written most of Maple in it.  It has been shown on this
newsgroup that Maple has similar functional-programming style
features, and is fast.


A system built on top of Common Lisp (like Macsyma, Reduce, Weyl, 
Mock-MMa) can in principle provide all those (very serious) features.
Some of them, like the Common Lisp Object System, are not available
in Mathematica, and, some might argue, represent a serious deficiency.
The lack of any appropriate structure for maintaining
assumptions is another major deficiency in Mathematica's design.

Most implementations of Common Lisp allow for links to other languages
such as calls to Fortran or C, if that is "serious" also.  

So for serious programming, I'd put Mathematica near the end of the list.
For non-serious programming, it is much more appealing, especially
if you can exercise some restraint in how much of it you use, and you
are able to avoid questions of scope, evaluation, and limited data
structure choices.





-- 
Richard J. Fateman
fateman@cs.berkeley.edu   510 642-1879
From: joe@decoy.uoregon.edu (Joe St Sauver)
Newsgroups: sci.math.symbolic
Subject: Re: MAPLE: Reading list of points from external file
Date: 16 Nov 1992 21:22:22 GMT
Organization: University of Oregon Network Services
Distribution: sci
NNTP-Posting-Host: decoy.uoregon.edu

In article  
<ROSE.92Nov10172623@t524i5.telematik.informatik.uni-karlsruhe.de>  
rose@t524i5.telematik.informatik.uni-karlsruhe.de (Ortwin Rose) writes:
> Hi,
> 
> I am a newcomer to MAPLE, so please be patient if this is a FAQ:
> 
> I have a list of points generated by another program, and would
> like to create a three-dimensional plot of the surface using
> MAPLE. Now, I did NOT find a solution to read these points from
> an external file into a list of points that can be used by
> "plots[pointplot]" within MAPLE! Since this is quite an easy
> task, I am quite sure that such a solution does exists. Any
> pointers how to proceed are appreciated!

Ortwin,

I am currently confronting a comparable problem -- I have a user with
huge matrices which he needs to manipulate. 

In *Mathematica*, he just says something like:

  r200=ReadList["covar-arma12.dat", Table[Real,{200}]];

and bang, there he goes -- Mathematica constructs a 2-dee matrix
like nobody's business. 

In *SAS/IML*, he just says:

  data rs;
    infile 'covar-arMA12.dat';
    input r1-r200 @@;
  proc iml;
    use rs; read all var _ALL_ into r200;

and off he goes -- happy as a clam. 

But, after extensively searching the new Springer Verlag Maple V 
manual set, let me refer you to section 11.8.5 in the Maple V
Language Reference Manual:

   "It is not possible in the present version of Maple to read
   arbitrarily formatted data [from a text file]."  (pp. 191)

That, to me, was just inconceivable, particularly for a package
which goes to some extreme to justify claims that it is a 
"programming language." To me, anything which cannot read data 
from a file in some relatively common format (i.e., free format, 
comma delimited format, fixed format or SOMETHING other than 
Maple-specific statement format) is NOT a programming language.

To say I'm unhappy about this "feature" of Maple V is an 
understatement. If input from text files is possible via some
trick I'm not aware of, I'd sure like to hear about it.

Joe St Sauver (joe@oregon.uoregon.edu)
Assistant Director, Academic User Services
University of Oregon Computing Center
Newsgroups: sci.math.symbolic
From: PEARCES@IBM3090.BHAM.AC.UK
Subject: Re: Eliminating zeroes ...MAPLE
Date: Thu, 19 Nov 1992 12:44:43 GMT
Organization: The University of Birmingham, United Kingdom

Newsgroups: sci.math.symbolic
From: hibrown@sarah.albany.edu (Herb Brown)
Subject: Re: new version of Maple for the Mac?
Organization: State University of New York at Albany
Date: Thu, 19 Nov 92 13:20:32 GMT

In article <BxxK58.DtH@watdragon.uwaterloo.ca> katherle@daisy.uwaterloo.ca (Kate Atherley) writes:
>
>Maple V Release 2 will be available for the Macintosh the end of
>the first quarter 1993.
>
>For more information, please contact info@maplesoft.on.ca.
>
>Kate
>Waterloo Maple Software Technical Suppport
>support@maplesoft.on.ca

Kate,

When will release 2 be available for the Amiga?

Thanks,

Herb


-- 
Herb Brown  Math Dept  The Univ at Albany  Albany, NY 12222  (518) 442-4640
Director,                                          hibrown@math.albany.edu  
Computer Assisted Instruction in Mathematics       hibrown@csc.albany.edu
--------------------------------------------------------------------------
From: jgk@osc.COM (Joe Keane)
Newsgroups: sci.math.symbolic
Subject: Re: real-valued complex fns in Maple
Summary: Take the real part.
Keywords: branch
Date: 16 Nov 92 07:57:25 GMT
Reply-To: Joe Keane <jgk@osc.com>
Organization: Versant Object Technology, Menlo Park, CA
Weather: sunny, high 70, low 43
Moon-Phase: waning gibbous (63% of full)

In article <CHUCK.92Nov11141130@nimbus.drexel.edu> chuck@nimbus.drexel.edu
(Wombozni Klik) writes:
>I've been trying to plot a function g(x) in Maple, which I know to be
>real-valued for the entire range of values that I'm looking at. Now,
>the function g(x) is complex in nature, but it, when used in
>conjunction with evalc and evalf, will produce a real number. 
>
>That's good, but whenever I try to plot the function, all I get is an
>empty graph. Nothing shows up on screen. 

I often have a function which is actually real-to-real but any expression for
it has complex intermediate values over some range.  I know the symmetries of
the function, but the computer can't figure this out.  Even numerically, due
to round-off error the results often have a small imaginary part, so this
throws it off.  One solution is just to explicitly take the real part, that
is, plot Re(f(x)) instead of f(x).  It's also a good idea to plot the
imaginary part to make sure, because sometimes a function shifts to another
branch when you don't want it to.

--
Joe Keane, amateur mathematician
jgk@osc.com (uunet!amdcad!osc!jgk)
Newsgroups: sci.math.symbolic
From: rivero <rivero@cc.unizar.es>
Subject: Re: What About OCRing Math?
X-Xxdate: Sat, 14 Nov 92 20:19:20 GMT
Organization: fisica teorica UZ
X-Useragent: Nuntius v1.1.1d12
Date: Mon, 16 Nov 1992 19:21:43 GMT

In article <1dsd2gINNdur@agate.berkeley.edu> Jon Forrest,
forrest@nobozo.CS.Berkeley.EDU writes:
>I'm aware of can do this, either because they can't recognize the
>math symbols or because there is no canonical representation for
>math that they could use as their intermediate form which could easily
>be saved as Maple, Mathematica, or whatever.
>
>Is this right? Is anybody working on OCRing math with this goal in mind?

So you know of a OCR capable of reading math formulae? Which one?
We have a lot of old material to be rewritten in TeX, and no time
for it.

By the way, I think that there is a package to translate TeX to
Mathematica and back, so perhaps a OCR with TeX output would
be the solution for your problem too.

Alejandro Rivero
.
Newsgroups: sci.math.symbolic
From: siegl@risc.uni-linz.ac.at (Kurt Siegl)
Subject: Re: Multiprocessor Implimentations of Symbolic Software?
Organization: RISC, J.K. University of Linz, Austria
Date: Mon, 16 Nov 1992 09:33:58 GMT

In article <1992Nov12.042527.10730@colorado.edu>, sherod@newton.Colorado.EDU (Scott Herod) writes:
> Are there multiprocessor implimentations of any of the larger 
> symbolic software packages?  It seems that this is the wave of
> future esp. since many of these packages stress functional as
> opposed to procedural programming.
> 
> Scott Herod

I've developed a parallel version of Maple (||MAPLE||).

||MAPLE|| is a portable Computer Algebra system in which logic programming provides 
parallelism and imperative programming provides efficiency. The system is
built as a combination between the parallel declarative programming language 
Strand and the sequential computer algebra system Maple.

Programming in that system is done in two layers.
The top (parallel, declarative) layer is Strand from where one may call Maple functions
to perform the time critical sequential parts. Due to that design ||MAPLE|| programs
are binary compatible among every hardware and independend of the number of processors.

There are also predefined generic parallel functions available, that alow nearly automatic
parallelization of algorithms used in Computer Algebra. Maple's Real Root isolation proc. 
for example has been parallelized by changing 5 lines in the source using that feature.

A parallelized user interface alows subsequently entering querys without waiting for
the availability of the previous result. Data dependencies are automaticaly
resolved by the system.

||MAPLE|| currently runs on Sequent shared memory machines, Transputer distributive
memory machines and on Networks of SUN Workstations.

Feel free to contact siegl@risc.uni-linz.ac.at for further information.

Kurt

----------------------------------------------------------
You can tell how far we have to go, when FORTRAN is the language of
supercomputers.    -- Steven Feiner
----------------------------------------------------------
Kurt Siegl / RISC, University of Linz, Austria
email: siegl@risc.uni-linz.ac.at
Tel:   *(7236)3231-66      Fax: *(7236)3231-30
From: sherod@news.Colorado.EDU (Scott Herod)
Subject: Question about Lie Symmetries of Differential Equations
Organization: University of Colorado, Boulder
Date: Tue, 17 Nov 1992 19:47:44 GMT

In their paper which appeared in 1989 in the Journal of Physics A.,
Winternitz and Levi mention that there is still an open question
concerning what determines whether an equation has non-classical
symmetries in the sense of Blumen and Cole which are not classical
symmetries.

Does anyone know if there has been any work done on this subject?

I am about to release a Mathematica package which will compute the
determining equations for both the classical and non-classical symmetries
for arbitrarily large systems of equations, and am interested in
theoretical work in this area.

Scott Herod
Applied Mathematics
University of Colorado, Boulder
(sherod@newton.colorado.edu)

Newsgroups: sci.math.symbolic
From: Richard J. Gaylord <gaylord@ux1.cso.uiuc.edu>
Subject: Re: The Real Meaning of Efficiency?  (Re: Serious Programming, etc.)
X-Xxdate: Fri, 20 Nov 92 14:17:28 GMT
X-Useragent: Nuntius v1.1.1d12
Organization: University of Illinois
Date: Fri, 20 Nov 1992 20:15:47 GMT
X-Xxmessage-Id: <A732A3F89D059B19@mm-mac25.mse.uiuc.edu>

i didn't mean to teach mathematica. i meant to teaching programming using
mathematica  because you can teach  different programming styles with the
language.
Newsgroups: sci.math.symbolic
From: katherle@daisy.uwaterloo.ca (Kate Atherley)
Subject: Re: new version of Maple for the Mac?
Organization: University of Waterloo
Date: Wed, 18 Nov 1992 21:10:20 GMT

In article <BxutwI.D45@news.cso.uiuc.edu> Richard J. Gaylord <gaylord@ux1.cso.uiuc.edu> writes:
>the recent announcement (which i've misplaced) of the new version of
>maple only mentioned  unix platforms. does anyone know when it'll come
>out on the mac?

Maple V Release 2 will be available for the Macintosh the end of
the first quarter 1993.

For more information, please contact info@maplesoft.on.ca.

Kate
Waterloo Maple Software Technical Suppport
support@maplesoft.on.ca
Newsgroups: sci.math.symbolic
From: monagan@inf.ethz.ch (Michael)
Subject: Re: MAPLE resources reccomendation
Organization: Dept. Informatik, Swiss Federal Institute of Technology (ETH), Zurich, CH
Date: Tue, 17 Nov 1992 17:50:50 GMT

In article <BxuxC6.Dxz@news.cso.uiuc.edu>, Richard J. Gaylord <gaylord@ux1.cso.uiuc.edu> writes:
> 
> this comment indicates a basic lack of understanding of the mathematica
> programming  language.  there are MAJOR differences in the languages of
> mathematica and maple (and macsyma). mathematica not only has  pattern
> matching (which can be very important) but it has many more built-in
> functions for functional style programming. 
> 
> other miscellaneous points:  what about  mathematica's graphics or its
> notebook front end? 
> 
> the basic question iswhat do you want out of your cas? if you are going
> to do serious programming,  mathematica  is totally in front of the
> others.

For serious programming, I would argue that the richer set of built-in data
structures and Maple, and the good procedural and functional programming
idioms make Maple better for serious programming.
The pattern matching in Mathematica is nice, but it comes at a cost.
The overhead of the pattern matcher makes the execution of the basic system,
e.g. function calls, relatively innefficient.
The lack of data structures in Mathematica makes it difficult to
write efficient programs.
For numerical computation, the model of floating point arithmetic in
Mathematica is considered by numerical analysts to be a disaster.
It is very difficult to implement numerical algorithms in Mathematica.
And the lack of canoncial forms for rational functions makes it
difficult and error prone for doing symbolic calculations.
That is my opinion.

Perhaps this observation says something about which
is the best language for serious programming.
If the Mathematica language was really that good, then why aren't the
Mathematica library routines themselves programmed in Mathematica?
Why is it that there are 350,000 lines of C code?
(the main reason I believe is that Mathematica is too innefficient for
serious programming, a reason also cited by WRI employees).
In Maple, most of the system (almost all of the algebra and calculus routines)
is programmed in Maple, not in C.  That this is possible and yet Maple is
still efficient in comparison says something about how good the language is.

Michael Monagan
From: fateman@peoplesparc.Berkeley.EDU (Richard Fateman)
Newsgroups: sci.math.symbolic
Subject: Quicksort in Mathematica
Date: 23 Nov 1992 18:44:44 GMT
Organization: University of California, Berkeley
NNTP-Posting-Host: peoplesparc.berkeley.edu


Someone asked me why I said  earlier in this thread why an O(n log n) 
algorithm might be  O(n^3) in Mathematica.

(This would be particularly embarrassing if it were being
used in a CS algorithms course, but similar concerns might
surface if one were to compare various RK formulas in a
computational physics class.)

I tried out this simple program, and it suggests that quicksort
in Mathematica is not O(n^3).  But it is not O(n log n) either.

I've spent too much time on this example this morning already,
I would be interested in seeing the results of a closer look, from
someone who is considering using Mathematica for CS students.
  RJF.


(* Here's a quicksort written in mathematica *)

sort[l_Integer,r_Integer] := Block[{i,j,x,w},
	i=l; j=r;
	x= A[[Floor[(l+r)/2]]];
For[, i<=j,,
	While [A[[i]] < x, i++];
	While [x < A[[j]], j--];
	If [i<=j,
		Block[{}, w=A[[i]];A[[i]]=A[[j]];A[[j]]=w; i++; j--]]];
If [l<r,sort[l,j]];
If [i<r,sort[i,r]]]

(*yes, that's all there is to quicksort if you wish to sort just one
  array A of n numbers, and call the sort routine by sort[1,n]. *)

(*Here are some programs to test it *)

makeA[n_]:=  A=Table[Random[Integer,100],{i,1,n}]

testsort[n_]:=Block[{},makeA[n];sort[1,n]]

(* results on MIPS-120 with Mathematica 2.0 for Timing[Do[testsort[n],{2}]] *)

(*note.. the built-in fn takes 0.15 sec  for sorting 1000 numbers, 0.37 for
 sorting 4000 elements.
(* above 3000, we timed just 1 run, not averaged, times 2. *)

results={{25,0.452},  
	{50,0.994},
	{75, 1.61},	
	{100,2.23},
	{200,5.17},
	{300,9.37},
	{400,12.23},
	{500,17.16},
	{800,33.97},
	{1000,47.51},
	{2000,149.95},
	{3000,326.28},
	{4000,561.7}}

p1=ListPlot[results,PlotJoined->True, PlotRange->All]
(* compare mathematica to n*log(n), match at n=300 *)
p2=Plot[0.005476*n*Log[n],{n,1,4000}] 
Show[{p1,p2}]

(* compare mathematica to n^2, match at n=1000 *)
p3=Plot[0.00006864*n^2,{n,1,4000}]
Show[{p1,p3}]

(* See all three -- *)

Show[{p1,p2,p3}]

(*Conclusions: The quicksort program above, as
executed by Mathematica, does not run in time proportional
to not n log n.  It is much slower.

It is not as slow as n^2, at least in the range 25 to 4000.

It is ridiculously slow compared to the built-in Sort, for any size.

On the positive side, Mathematica's graphing tools are handy to show
how inefficient its programming language is. *)








-- 
Richard J. Fateman
fateman@cs.berkeley.edu   510 642-1879
Newsgroups: sci.math.symbolic
From: edgar@riemann.math.mun.ca (Edgar Goodaire)
Subject: Maple V for Windows
Organization: CS Dept., Memorial University of Newfoundland
Date: Wed, 18 Nov 1992 13:48:02 GMT

With all this talk about a version of Maple, some people running Maple on DOS machines are wondering if the Windows version will ever appear.  It was
promised for September, 1992.    
.

Newsgroups: sci.math.symbolic
From: chuck@nimbus.drexel.edu (Wombozni Klik)
Subject: Re: MAPLE: Reading list of points from external file
	<1e93eeINNj59@pith.uoregon.edu> <CHUCK.92Nov16190416@nimbus.drexel.edu>
	<1992Nov17.143435.14411@sarah.albany.edu>
Organization: Drexel University Department of Physics
Date: Wed, 18 Nov 1992 23:23:59 GMT
Distribution: sci.math.symbolic
X-Posted-From: nimbus.physics.drexel.edu
NNTP-Posting-Host: sol.ctr.columbia.edu


The question we're talking about here is about how to bring data INTO
maple. Once we do that, then we can go about playing with it. 

I saw someone else mention that version 2 has scanf-like features to
read in text. That would make us C programmers happy... ;-)

Chuck
--
Chuck Browne                            | Frisbeetarianism: The belief that  
Drexel University Department of Physics | when you die, your soul goes up
chuck@nimbus.physics.drexel.edu         | on the roof and gets stuck.
Newsgroups: sci.math.symbolic
From: sarrenhe@leland.Stanford.EDU (mo Saarenheimo)
Subject: Plotting implicite functions in Mathematica
Organization: DSG, Stanford University, CA 94305, USA
Date: Thu, 19 Nov 92 17:40:01 GMT

I am using Mathematica, and my problem is the following:

I have an implicite function F(X,A)=0, 0<A<1, which can not be solved 
explicitly for X. I wish to plot X as a function of A. Here's the best
I've been able to work out.

Plot[X/.FindRoot[F[X,A]==0,{X,Xinit}],{A,0,1}]

The obvious problem with this approach is that, for every value of A, the
iteration for X begins from the same initial value Xinit. This is, of
course, inefficient, and often there exists no initial value Xinit for
which the iteration converges for every value of A.

Since F(X,A) is continuous, the obvious alternative is to use the solution
reached by FindRoot for previous value of A as the initial value for the 
next iteration.

Can somebody suggest an elegant and efficient way to do this?

Thanks in advance,

Tuomas Saarenheimo

Newsgroups: sci.math.symbolic
From: mroussel@alchemy.chem.utoronto.ca (Marc Roussel)
Subject: Re: Maple V Release 2
Keywords: Maple
Organization: Department of Chemistry, University of Toronto
Date: Tue, 17 Nov 1992 20:40:47 GMT

In article <1992Nov17.175606.20110@neptune.inf.ethz.ch> monagan@inf.ethz.ch
(Michael) writes:
>     New features that have been added for Maple V Release 2
[...]
>Also, running a Maple session in a
>shell under the X Window system, interface(plotdevice=x11); will allow you to
>access the X plotting facilities.

     Hurrah!  I really hated xmaple and the only reason I ever used it
was to get the plotting to work correctly.

>5: X Window interface
>The interface has been redesigned to follow Motif style conventions.

     Hurrah!  The non-Motif behaviour was the main reason I hated
xmaple.  Maybe I should give it a try when we get R2 installed.

>- Routines for complex numbers Re(z), Im(z), argument(z), conjugate(z), csgn(z)

     Everybody who hadn't written their own versions of all of these already,
raise your hand.  I didn't think so.  :-)

>9: Symbolic simplifications for min, max, trunc, round, ceil, floor, Re, Im
>---------------------------------------------------------------------------
>These routines now do quite a number of symbolic simplifications.
>Note, interval arithmetic is used by the signum function in these examples
>to prove that the constant Pi < sqrt(10) and that cos(2) < 0.

     Does this new ability extend to ordinary if statements?  Under the
current version of Maple V,

f := proc(x) if x<Pi then less else more fi end;

is a legal procedure definition but

f(1);

generates an error.  (If we replace Pi with 2 in the procedure, it works
like a charm so the problem is simply that Maple doesn't know how big Pi
is compared to other numbers.)  It's easy to work around this (make the
condition evalf(x-Pi)<0), but it would be nice if it worked correctly without
special programming.

>Integration now knows about the Heaviside and Dirac functions

     About time.  (Don't take this personally.  I needed this last month
and I'm still a little grumpy about it.)

				Marc R. Roussel
                                mroussel@alchemy.chem.utoronto.ca
From: engel@vms.huji.ac.il
Newsgroups: sci.math.symbolic
Subject: What is added in Mathematica 2.1?
Date: 22 Nov 92 11:23:24 GMT
Distribution: world
Organization: The Hebrew University of Jerusalem

Hello,
What is new in version 2.1 compared to 2.0?
Thanks in advance,
Micky Engel
( e-0address: engel@hujivms.bitnet or engel@vms.huji.ac.il)