HDTenEightyP/NetNews huggingface dataset:
From: siegman@EE.Stanford.EDU (Anthony E. Siegman)
Subject: Re: Mma and linear algebra
Organization: Stanford University
Date: Wed, 22 Jul 92 02:57:10 GMT

From Dr. William V. Smith):

>Someone asked about Mma and linear algebra, in particular, finding the
>eigenvalues and eigenvectors of the matrix
>
>{{0,1,0},{0,0,1},{1,1,0}}
>
>I tried "Eigensystem" on this on my home NeXT, and it did fail.
>Mathematica has problems with complex numbers.  I also just
>tried it on a system at work (a MIPS) and it gave the algorithm
>failed message. 

Try {{0.,1.,0.},{0.,0.,1.},{1,.1.,0.}}.  On a Mac SE/30 with mma 2.0
both the eigenvalues and eigenvectors come out almost instantaneously.
Without the dots the eigenvalues come out in a few seconds, and I gave
up on the eigenvectors after a minute or so.

One thing I've learned from several helpful msgs from David Withoff at
wri is that mma behaves _very_ differently in many situations
depending upon whether you write integers (including especially zero)
with or without a decimal point.  Even something like

    m = 1; rootTwo = Sqrt[2.]; f[x_] := Exp[ - m rootTwo x^2]

can behave differently for "m = 1" or "m = 1." despite the fact that
you'd think the product "m rootTwo' would lose the pure number
identification.
From: wucm@mt.luth.se (Wu Changming)
Newsgroups: sci.math.symbolic
Subject: Help needed with numerical inverse of a matrix in Maple
Date: 30 Jul 92 14:41:00 GMT
Reply-To: Wu Changming <wucm@mt.luth.se>
Organization: University of Lulea, Sweden
UUCP-Path: {uunet,mcvax}!sunic!mt.luth.se!wucm


I am using Maple V, but I do not know much about Maple, so I need some help here.

I need to do an inverse of a 8x8 matrix. Since the computer never gives the
result, I plan to do the inverse numerically. However I got the error message:

##################################################
Error, (in normal/doit) floats not handled
--------------------------------------------

Then I use the following to do a test.

##################################################
 K := array(1..4, 1..4):
 for ii from 1 by 1 to 4 do
  for jj from 1 by 1 to 4 do
    K[ii, jj] := Pi**(1/ii*jj) + I**(ii+jj) :
   od;
 od;

 IK := inverse(K):
 IK :=  map(evalc, map(evalf, map(evalm, IK ) ) ):
 print(IK);
---------------------------------------------------  

which gives the symbolic solution first, and then the numerical solution.

The I do the above calculation in this way:

##################################################
 K := array(1..4, 1..4):
 for ii from 1 by 1 to 4 do
  for jj from 1 by 1 to 4 do
    K[ii, jj] := evalc( evalf( Pi**(1/ii*jj) + I**(ii+jj) )):
   od;
 od;

 IK := inverse(K) :
 print(IK)
-----------------------------------------------------


The program gives  `Error, (in normal/doit) floats not handled' when it is doing
the inverse.

Could someone help me to do numerical inverse of a large matrix?

Thanks

Wu Changming
Newsgroups: sci.math.symbolic
From: whitmore@iastate.edu (Kurt D Whitmore)
Subject: Re: Dashed Lines in Graphics Question
Organization: Iowa State University, Ames IA
Date: Wed, 22 Jul 1992 04:57:32 GMT

In <1992Jul22.004307.15466@EE.Stanford.EDU> siegman@EE.Stanford.EDU (Anthony E. Siegman) writes:

>I'm doing things like:

>   g1 = Plot[ f1[x], {x,a1,b1}, DisplayFunction->Identity];

>   g2 = Plot[ f2[x], {x,a2,b2}, DisplayFunction->Identity];

>   g3 = Plot[ f3[x], {x,a3,b3}, DisplayFunction->Identity];

>   Show[ g1, g2, g3, DisplayFunction->$DisplayFunction]

>to put several curves on a single plot.  What can I put in the g2
>statement, say, to get a distinctive dashing for just that one curve?
>Everything I've tried seems to turn on dashing for all the other
>curves as well.


I have a similar question on Queue at support@wri.com, but I haven't heard
from anyone since I sent it on July 14th.

Kurt D. Whitmore
whitmore@iastate.edu
Newsgroups: sci.math.symbolic
From: jimsk@vulcan.anu.edu.au (Jim Skea)
Subject: Information on SCHOONSHIP requested
Keywords: SCHOONSHIP, Feynmann diagrams
Organization: Computer Services Centre, Australian National University
Date: 30 Jul 92 15:12:24 GMT

Replies by E-mail please,if possible.

Thanks in advance.
Newsgroups: sci.math.symbolic,sci.math,sci.math.num-analysis,k12.ed.math,comp.edu
From: jk87377@cc.tut.fi (Juhana Kouhia)
Subject: Re: Comments on SymbMath and MathCad
Organization: Tampere University of Technology
Date: Wed, 22 Jul 92 15:29:02 GMT



Somebody recently posted a note that Dr. Huang seem to post
commercials on his program; specially because he does
large crosspostings.

Indeed, after comment on his postings, he has posted few similar
postings as he would like to not care other netters' requests
to post announces only in appropriate newsgroups, that is,
in sci.math.symbolic.


>Way to go Symbmath!"  

So, would you, Dr. Huang, please respect Usenet rules on making
commercials and post to appropriate newsgroup?

It may be that answer to this request is another flow of Dr. Huang's
'announces'.... sad.


To me the best place for info on your package is FAQ article;
there's allready some other packages listed in entry:

6Q:  Where can I get <Symbolic Computation Package>?
    This is not a comprehensive list. There are other
    Computer Algebra packages available that may better
    suit your needs.

So, I suggest that you e-mail your info for your programs
to FAQ keeper who put (and edit to appropriate format)
them to FAQ article.

FAQ article's purpose is not to store entire commercial of yours,
Dr. Huang, but only give a pointer where from individuals
can get the full information, that is, from you.


Dr. Huang should note that he is only who posts such commercials
for his eventually commercial program.
This is not personal attack against Dr. Huang, instead it is question
of common sense (Distributors of other packages doesn't do similar
postings).


Thank you,

Juhana Kouhia
From: steve@ramsey.cs.laurentian.ca (Stephen R. Czapor)
Newsgroups: sci.math.symbolic
Subject: Re: simultaneous equations.
Summary: Please post entire system.
Date: 28 Jul 92 03:01:47 GMT
Organization: Dept. of Computer Science, Laurentian University, Sudbury, ON

In article <1992Jul27.200213.9446@ennews.eas.asu.edu> nikhil@enuxha.eas.asu.edu (Venkatesh Nikhil) writes:
[
[mathgroup,
[	  I need your help on the following problem.I have 8 equations as
[follows:
[a=P*mcp*ac*tc*tf*tr
[b=P*mcp*(4*ac*tc*tf+ac*tc*tr+2*af*tc*tr-ac*tf*tr+ac*l*tc*tf*tr)
[c=P*mcp*(4*ac*tc+4*af*tc+l*4*ac*tc*tf+l*ac*tc*tr+2*l*af*tc*tr-l*ac*tf*tr)
[d=.....
["
["
["
[h=..............
[
[I need to solve these equations simultaneously for "ac" in terms of a,b,c,d,
[e,f,g & h. So, here i need to eliminate the other variables like P, mcp, tc,
[tf, tr, l, L, af, etc. 
[I am using mathematica and tried the commands eliminate (but my PC ran out
[of memory before giving me the solution) and Solve[eq,var,elim] ( but this one
[did not work too).
[Have any of you encountered a similar problem? Is there a way to obtain "ac" in
[terms of just a, b, c, d, e, f, g&h eliminating the rest. I would appreciate
[your suggestions. Is there any other software package i could use for this
[problem?
[           ( REST OF ARTICLE DELETED )

All of the systems Macsyma, Maple and Reduce have facilities for
solving nonlinear algebraic systems, classical elimination (via
resultants), and Groebner bases - and, in general, all will be
better than Mathematica's for large problems.

There are, however, two things to note about your equations.  For
one, you say you have 8 equations but mention 9 variables (including
"ac") - so you won't be able to eliminate as far as you'd like.
For another, you should know that with systems larger than a few
equations/variables, the chances of success are slim - unless you
are very lucky.  Even then, you will probably need far more than a
few megabytes on a PC (unless you are very, very lucky) irrespective
of which software you use.  The fact that your equations also
involve the parameters "a, b, ..." further complicates things.

Perhaps if you posted the complete set of equations, you would
get a more definite answer.  Also, if there is any chance of
augmenting your system with further equations, you should include
(some of) those.
=========================================================
Steve Czapor, Dept. of Math. & C.S., Laurentian Univ.
{The opinions expressed above are mine, etc.}
Newsgroups: sci.math.symbolic
From: abbasi@star.enet.dec.com (My name is Nasser ABBASI)
Subject: New Class of functions found, impact of CAS on math
Organization: Digital Equipment Corporation
Date: Tue, 21 Jul 1992 20:32:56 GMT


there is an interesting article about how using computer algebra
systems (MAPLE), it helped in finding a new class of function, called
terminal summations.

look it up, it is on page 35 of July 20,1992 Electronics Engineering
Times magazine.

it is too long to type, so here are some psudo-random quotes from the
article :(printed with no permission)

"Terminal summation is more comprehensive than any other convergence-
forcing method, and a lot of them have been developed over the years"

"the ability to automate symbolic algebra now allows us to explore
this obscure are. we can extract approximate values for these functions
and characterize their values"

"Phipps expects computer algebra systems to bring other hypothetical
mathematical objects into the light of day. The results could be
revolutionary because automated algebra applies computational power
at a higher level, automating the symbolic language of science in much
the same way that AI languages such as LISP automated mathematical logic.
Terminal summation has a potentially wide area of applications because
it can speed the convergence of virtually any algorithm, according to Phipps."

/Nasser

Newsgroups: sci.math.symbolic
From: hshlswe1@w222zrz.zrz.tu-berlin.de (Hilmar Schlegel)
Subject: Re: A Problem with Reinstalling Mathematica for Windows
Reply-To: hshlswe1@w222zrz.zrz.tu-berlin.de (Hilmar Schlegel)
Organization: ZRZ/TU-Berlin
Date: Mon, 27 Jul 1992 15:35:24 GMT

In article <1992Jul27.143901.6149@usenet.ins.cwru.edu>, cfw2@po.CWRU.Edu
(Charles F. Wells) writes:
> 
> I run Mathematica for Windows on a Gateway 486-33 machine with
> 
> an ATI Graphics Ultra Video board.  Today, I experimented with
> 
> going into 800 x 600 video mode instead of the usal 640 x 480. 
> 
> I then used the Defaults window in Mma to enlarge the input and
> 
> output files.  This did not take effect in the Newnb-1 window,
> 
> so I exited Mma and tried to restart it.  It froze at 11%.  I
> 
> tried many things, including turning the machine off and on and
> 
> changing back to 640 x 480 mode.  The same thing always
> 
> happened.  So I reinstalled Mathematica.  It worked now, but the     
                  ^^^^^^^^^^^^^^^^ This seems to be the only way for
getting a "cleam" Math-installat. The program is generally
rather unstable  and produces sometimes history dependent error
states of the machine.
This is a"must" due to the responses from the "support":
They consider this as their "standard" & don't care about interferences
with other software.

 Defaults window was in a horrible mess.  It showed part of the
> 
> font commands that the notebook normally does not show.
> 
> 
> 
> I suspected that the installation process had inserted a new
> 
> defaults.ma file but had left an incompatible defaults.mb file
> 
> on the disk.  So I renamed the defaults.mb file and reloaded
> 
> defaults checking the no  binary option.  Now everything works
> 
> fine.  
> 
Be happy that you  managed the problem at your site: other sites other
problems!
 
> 
> I don't know what caused the problem originally, but I thought
> 
> others would want to know about this problem that reinstallation
> 
> can cause.
I'm not an expert in this field but I bet it is more philosophy
than debugging.
The glamourous surface of a progam is not all.... but some care with 
the inner workings is needed too. In my opinion it is a pitty for some
pretty algorithms to live in such an environment.
Maybe a "remake" of the kernel would enjoy the masses.
Good luck,
Hilmar Schlegel (hshlswe1@w250zrz.zrz.tu-berlin.de)
 
> 
> 
> 
> 
> Charles Wells
> 
> Department of Mathematics
> 
> Case Western Reserve University
> 
> 10900 Euclid Avenue
> 
> Cleveland, OH 44106-7058
> 
> 216-368-2893

Newsgroups: sci.math.symbolic
From: fateman@peoplesparc.Berkeley.EDU (Richard Fateman)
Newsgroups: sci.math.symbolic
Subject: Re: simplification
Date: 26 Jul 1992 00:05:14 GMT
Organization: University of California at Berkeley
NNTP-Posting-Host: peoplesparc.berkeley.edu

Reader of sci.math.symbolic who want someone else's magic program to
do simplification, or integration, or ...
might find it useful to look at the following book:

Peter Norvig: 
  Paradigms of Artificial Intelligence Programming: Case studies in
Common Lisp.  Published by Morgan Kaufmann. 1992

Chapter 8:  Symbolic Mathematics: A Simplification Program (22 pages)
Chapter 15: Symbolic Mathematics with Canonical Forms (20 pages)

Although you might argue with the approach here and there, 
all the (working!) code is included. Chapter 8 includes, in addition
to a simplifier,  a parser, display, differentiation and integration
(derivative divides).

You may find some of other chapters are also relevant (making programs
run faster, compiling rules, pattern matching, prolog,  etc)

We use this book for an "Advanced AI programming" course at
Berkeley.  I highly recommend it for anyone who wants to see
examples of well-written non-trivial common lisp code solving
classical problems, building tools, playing games, parsing natural
language etc.

RJF

-- 
Richard J. Fateman
fateman@cs.berkeley.edu   510 642-1879
Newsgroups: sci.math.symbolic
From: stefans@bauv106.informatik.unibw-muenchen.de (Stefan Schwarz)
Subject: Mathematica support, a black hole ??
Organization: Universitaet der Bundeswehr Muenchen (Germany)
Date: Tue, 21 Jul 1992 10:22:48 GMT

Two weeks ago i sent a problem concerning Mathematica installation on PC
to support@wri.com. My email was acknowledged immediately and i was informed
about a response time to my question of 2 days.

Until today nothing happened.

Does anybody has experiences with this type of support.

Stefan
-- 
________________________________________________________________________________
Stefan Schwarz                            University of the armed forces, Munich
Laboratory for graphical data processing  W-8014 Neubiberg, FRG
--------------------------------------------------------------------------------
From: smithw@hamblin.math.byu.edu (Dr. William V. Smith)
Newsgroups: sci.math.symbolic
Subject: Re: Mma and linear algebra
Date: 21 Jul 92 23:43:19 GMT
Organization: Brigham Young University-Math. Dept

Someone asked about Mma and linear algebra, in particular, finding the
eigenvalues and eigenvectors of the matrix

{{0,1,0},{0,0,1},{1,1,0}}

I tried "Eigensystem" on this on my home NeXT, and it did fail.
Mathematica has problems with complex numbers.  I also just
tried it on a system at work (a MIPS) and it gave the algorithm
failed message.  You can make Mma find eigenvectors, but it requires
a bit of work.  I tested Maple with this one, it had no problems.

-Bill
--
EMail:  smithw@hamblin.math.byu.edu  or  uunet!hamblin.math.byu.edu!smithw
SMail:          Math Dept. -- 314 TMCB; BYU; Provo, UT 84602 (USA)
NeXTmail:                   bill@mathnx.math.byu.edu
Phone:            +1 801 378 2061         FAX:  +1 801 378 2800
Newsgroups: sci.math.symbolic
Subject: Re: Theorist for the mac. Also Maple question.
From: guelzow@brandonu.ca
Date: 30 Jul 92 10:01:09 CST
Organization: Brandon University, Brandon, Manitoba, Canada

In article <1992Jul29.221406.29162@unlinfo.unl.edu>, 
dcheenne@unlinfo.unl.edu (Dominique J. Cheenne) writes:
> 
> Does anyone on this group have comments about the software called "Theorist"
> by Prescience Inc.? It received a 5 mice rating from MacUser magazine a couple
> of years ago but I cannot find much info on it...

Theorist is very different from Maple and Mathematica. Essentially, it doesn't
do much work for you but helps you to do the work itself. A theorist "notebook"
consists essentially of transformation/simplification/expansion rules that you
can define. On request it will aply these rules to parts of your equations.
Moreover, it has very good graphing abilities and some calculation abilities.
Of course it includes such things as factoring polynomials etc.

I like this programme since I can let it do whatever I want (nearly), which is
quite important since many of my calculations take place in strange structures
(squags, SQS-skeins,...)

If you have any more questions about it just ask. By the way, Theorist loves
memory but can be used in 1Meg.

Andreas
-------------------------------------------------------------------------------
Andreas Guelzow  Dept. of Mathematics & Comp. Sc. Brandon University MB Canada
Guelzow@BrandonU.Ca
Newsgroups: sci.math.symbolic,ba.seminars,ucb.seminars
From: nb@Sunburn.Stanford.EDU (Nancy Blachman)
Subject: The BMUG Math SIG Meeting July 29 - David Stoutemyer: Derive
Originator: nb@Sunburn.Stanford.EDU
Organization: Computer Science Department,  Stanford University.
Distribution: ba
Date: Mon, 27 Jul 1992 07:24:48 GMT


                               Derive

             Computer Algebra Program for the IBM PC 

                                and

             Hewlett Packard 95 LX Palmtop Computer 

                      talk and demonstration

                                 by

                          David Stoutemyer

       BMUG Math SIG Meeting at 7 pm on Wednesday, July 29, 1992


Live demo.  Questions and answers.  Free Macademia nuts from Hawaii!

This presentation will be at the BMUG office at 2055 Center Street
in Berkeley.  The office is near the north west corner of Center Street
and Shattuck Ave. which is half a block from the Berkeley BART station.

Driving directions:
	Take the University exit off 80.
	Head east on University toward the UC Berkeley campus.
	Turn right at Shattuck (McDonalds will be at the corner.)
	Go 2 blocks.
	Turn right on Center and look for parking.
	There are public parking garages on the right and the left
	side of the street.

For more information on the Berkeley Macintosh Users Group (BMUG) 
Mathematics Special Interest Group (SIG), contact: 
	Nancy Blachman
	Variable Symbols, Inc
	2161 Shattuck Ave., Suite 202
	Berkeley, CA  94704-1313
	Email: nb@eris.berkeley.edu
	or     nb@cs.stanford.edu
	Fax: 510-843-8702
	Telephone: 510-843-8701
Newsgroups: sci.math.symbolic
From: reinhart@symcom.math.uiuc.edu (Georg Reinhart)
Subject: Review of Maple
Organization: Math Dept., University of Illinois at Urbana/Champaign
Date: Fri, 24 Jul 1992 14:35:36 GMT



I just read the review of Mathematica in the May 1992 issue of
the Journal of Symbolic Computation. Is there a similar review
about Maple? Thanks.

Georg Reinhart
Newsgroups: sci.math.symbolic
From: ALEWAND@ibm.gwdg.de
Subject: Problem with PostScript
Organization: GWDG, Goettingen
Date: Wed, 29 Jul 92 12:52:08 MSZ

I've some problems with Mma:
 
Installing Mma(2.0.2) with "EPS-Format" I can't print out this simple graphic:
 
In[1]:=Plot[x,{x,0,1},Frame->True,FrameLabel->{"1","2","3","4"}]
Out[1]=-Graphics-
In[2]:=HardcopyF[%,"test.eps"]
Out[2]=-Graphics-
 
The test.eps-file begins (after the preview) with a lot of definitions
 of macros but
the commands Minner, Mouter and Mrotsboxa (for example) are not included.
Later in this file there are some lines like
  [(0)] 0.02381 0 0 2 0 Minner Mrotsboxa
and the printer is (of course!!) not able to interpret these lines correctly.
 
Is there anybody with the same problem? Is this bug (?) fixed in later
versions?
 
If somebody has managed to print this file, I would be grateful to get
(via e-mail) a file with the definitions of the macros.
 
Thank you in advance!
 
 
Achim Lewandowski
Institut fuer Statistik und Oekonometrie
3400 Goettingen
Germany
email: alewand@ibm.gwdg.de
From: phr@soda.berkeley.edu (Paul Rubin)
Newsgroups: sci.math.symbolic
Subject: Re: Finding convex  hull ?
Date: 23 Jul 92 00:03:47 GMT
Organization: CSUA/UCB
NNTP-Posting-Host: soda.berkeley.edu
In-reply-to: christian@ai.univie.ac.at's message of Wed, 22 Jul 1992 11:31:18 GMT

The best known algorithms for convex hull are very complicated.
One can't assume that a constraint system will do something efficient.
I believe "Compuational Geometry" by Preparata and Shamos has some
info on convex hull algorithms.
Newsgroups: sci.math.symbolic
From: thor@vivaldi.psu.edu (Thomas Moertel)
Subject: Re: 3D scatter plots using Mathematica
Organization: Pennylvania State University
Date: 30 Jul 92 01:09:33

>         I need to produce 3D surfaces as the solution to various
> regression analysis and plot those with the original points in 3D, ie the
> 3D equivalent of a linear regression with both regression line and data
> points visible. I am using Mathematica 2.0 on the NeXT. Be merciful I'm
> not a Mathematician.
> 
>         Andrew Penn
 
What you need to do is create 2 plots, one of the sample points and one 
of the regression surface.  Then you can combine them with the Plot[] 
command.  Using 2D for example, you could combine plots of sine and cosine
like this:
 
  plot1 = Plot[Sin[x], {x, 0, Pi}];  (* first plot *)
  plot2 = Plot[Cos[x], {x, 0, Pi}];  (* second plot *)
  Show[plot1, plot2]                 (* combo plot *)
 
Here's a more realistic example in 3D.  Let's say your regression surface is 
given by
 
  surfaceEq = x^2 + y^2 + z^2 == 16; (* sphere w/radius 4 *)
 
We can make a plot of this surface and some (fake) data like so:
 
  (* this function calculates the z-value of a point on the suface *)
  (* at the given (x, y) coordinates *)
  
  f[x_, y_] := Evaluate[z /. Flatten[Solve[surfaceEq, z]]]
  
  (* this function randomly generates a "pretend" data point *) 
  
  samplePoint[] :=
    Module[{r, phi, x, y},
      r = Random[Real, 4.0];
      phi = Random[Real, N[Pi/2]];
      x = r Cos[phi];
      y = r Sin[phi];
      {x, y, f[x, y] + Random[Real, 0.25]}
    ]
  
  (* let's make a fake set of data *)
  
  data = Table[samplePoint[], {50}];
  
  (* now let's plot the data *)
  
  Needs["Graphics`Graphics3D`"]
  
  pointPlot = ScatterPlot3D[data]
  
  (* let's plot the regression surface *)
  
  surface =
    ParametricPlot3D[
      {
        r Cos[phi],
        r Sin[phi],
        Re[f[r Cos[phi], r Sin[phi]]]
      },
      {r, 0, 4}, {phi, 0, Pi/2.0}
    ]
  
  (* finally, we can combine the plots! *)
  
  Show[surface, pointPlot]
 
Under less ideal conditions some sample points may be hidden by the
surface.  Therefore, you may want to make several plots from different
viewpoints so that all the sample points can be seen. 
 
I hope this helps.
 
--Tom
--

Tom Moertel                 Pennsylvania State University
thor@vivaldi.psu.edu        "Them bats is smart. They use radar!"  ;-)
From: ara@zurich.ai.mit.edu (Allan Adler)
Newsgroups: sci.math.symbolic
Subject: Re: Symbolic Algebra subroutine library?
Date: 25 Jul 92 18:27:19 GMT
Article-I.D.: camelot.ARA.92Jul25132719
	<whitmore.712081194@pv343f.vincent.iastate.edu>
Organization: M.I.T. Artificial Intelligence Lab.


Although intended more for number theoretic applications and numerical
analysis, PAIR/GP can do symbolic manipulations and is available for free, 
unlike Mathematica.

PARI is basically a library in C or C++. For interactive use, one
can use GP which uses the PARI library. You can obtain PARI/GP for free. 

Here is a fragment of a message I received from Henri some time ago:

"Pari now runs on many different platforms, including 386 boxes
(although we do not support this port by lack of means). The
Unix and Macintosh versions are available by anonymous ftp from
math.ucla.edu (128.97.4.254, where a NeXT version is also available)
and in Europe from 134.157.51.2, directory dist/pari, and soon on
nuri.inria.fr (128.93.1.26)."


Allan Adler
ara@altdorf.ai.mit.edu
Newsgroups: sci.math.symbolic