HDTenEightyP/NetNews huggingface dataset:
From: wabe@ukc.ac.uk (W.A.B.Evans)
Newsgroups: sci.math.num-analysis
Subject: Re: 3D Regression
Date: 11 Apr 92 11:39:19 GMT
Reply-To: wabe@ukc.ac.uk (W.A.B.Evans)
Organization: Computing Lab, University of Kent at Canterbury, UK.

In article <44424@mentor.cc.purdue.edu> vbl@mace.cc.purdue.edu (Randall Julian) writes:
>I am interested in fitting a 3D data set to a user specified equation.  The
>equation is linear (Legrendre Polynomials) in the coefficients.  _Numerical
>Recipes in C_ has no routines of this type, quitting at 2D, as most references
>do.  If anyone has a reference to some C code for this please post, or
>e-mail me.
>
>|   Randy Julian                              |   Purdue University           |


	Surely, what you need here is EXACTLY the usual LINEAR regression
code but with the (trivial) modification that the fitfunction be defined as
a function of NV variables (2 or 3 in your case) rather than 1. All other
aspects are (I believe) unaltered.

	My own codes for (Linear and Nonlinear) Regressions (in FORTRAN)
have this option built in (the default being NV=1) - and have served me
perfectly well for the odd occasions when I needed a least squares fit to
a function of more than 1 variable.

						W. Alan B. Evans
						[ wabe@ukc.ac.uk ]
From: carter@iscnvx.lmsc.lockheed.com (Mark R. Carter)
Newsgroups: sci.math.num-analysis
Subject: Re: radial spheroidal wave functions
Date: 10 Apr 92 01:58:17 GMT
Organization: Lockheed Missiles and Space Co.

In article <6006@geocub.UUCP> cohen@alioth.greco-prog.fr (Henri Cohen) writes:
>I am posting this for a friend. Please post or e-mail to me.
>-------------------------------------------------------------
>
>We are working on radial spheroidal wave functions of the first
>kind R_mn^1(c,x) (using Flammer's notation). It is currently
>indicated in handbooks that in the limit of large cx:
>  
>     R_mn^1 ---> cos(cx-(n+1)pi/2)
>
>Actually, for our own purposes, we need a more complete expression
>for this behavior (namely including some kind of dependence on m)
>when, whatever x (real or complex from 0 to infinity) c tends to
>infinity.
>
>Moreover, direct numerical computations seem to indicate that for
>cx purely imaginary
>
>     R_mn^1(c,x) < R_mn'^1(c,x) if n>n'.
>
>Has this conjecture been proved?
>Any pointers to the literature and or answers are welcome. Thanks
>in advance.
>
>	J. Curely and R. Georges, Talence France
>
>--------------------------------------------------------------

Some of us experts have never heard of "Flammer" notation. In particular,
what is m for which you need the dependence? 
Usually m would be a parameter for a spherical angular harmonic 
in the range -n <= m  <= n. From what you 
have stated, and the usual results of spherical Bessel functions, it
is utterly trivial to derive the large x radial dependence for complex c. 
It would
be interesting to have a little more background on the modification of 
the spherical equation or the physical situation it describes or the
numerical work you have put into the problem apropos 
sci.math.num-analysis.

I feel I am missing the point or perhaps once again doing someone's 
homework set. Is c taken to be large and x varied,or both together? 
Since c is the separation constant, it may matter.

In short, more details please. :-)

					Mark R. Carter, Ph.D.
From: jbuske@mountain.rmnug.org (Jeff Buske)
Newsgroups: sci.math.num-analysis
Subject: Re: waves in random media
Keywords: Acoustic wave propagation
Date: 5 Apr 92 07:47:58 GMT
Article-I.D.: nugget.1992Apr5.074758.451
Organization: Rocky Mountain NeXT Users' Group

In article <1992Apr4.211908.10458@tc.cornell.edu>  
mhumi@theory.TC.Cornell.EDU (Mayer Humi) writes:
> I shall greately appreciate if somebody who has a program to
> simulate the propagation of acoustical or EM waves in random
> media will  willing to share it with me. Also any pointers to  
such 
> a program (PD or otherwise) will be greately appreciated. 
> send answers to mhumi@wpi.wpi.edu Thank you. MH.
> Regarding your question on wave propagation check out PiezoCAD.   
It models electro-mechanical transducers as a one dimensional  
transmission line problem.  Contact George @ Sonic Concepts
20018 163 rd Ave NE
Woodinville, WA 98072
Newsgroups: sci.math.num-analysis
From: dow@nova2.stanford.edu (Keith Dow)
Subject: Optimization Question Two 
Organization: Stanford University
Date: Fri, 17 Apr 1992 03:42:24 GMT

One last question.  It seems to me that nonlinear optimization
is nonlinear optimization is nonlinear optimization.  So why
are there different routines for fitting data to a nonlinear
function and for optimizing a nonlinear function?
From: vbl@mace.cc.purdue.edu (Randall Julian)
Newsgroups: sci.math.num-analysis
Subject: 3D Regression
Date: 8 Apr 92 13:59:18 GMT

I am interested in fitting a 3D data set to a user specified equation.  The
equation is linear (Legrendre Polynomials) in the coefficients.  _Numerical
Recipes in C_ has no routines of this type, quitting at 2D, as most references
do.  If anyone has a reference to some C code for this please post, or
e-mail me.

Thanks.

+---------------------------------------------+-------------------------------+
|   Randy Julian                              |   Purdue University           |
|   Aston Laboratory for Mass Spectrometry    |   Department of Chemistry     |
|   vbl@mace.cc.purdue.edu                    |   Chemistry Box 519           |
|   (317)494-6898                             |   West Lafayette IN, 47907    |
+---------------------------------------------+-------------------------------+
From: jim@heart.circ.upenn.edu (Jim Streicher)
Newsgroups: sci.math.num-analysis
Subject: WANTED: digital filter source code
Summary: looking for examples of digital filtering
Keywords: digital filter examples
Date: 8 Apr 92 17:14:19 GMT
Followup-To: sci.math.num-analysis
Organization: Department of Bioengineering


I am looking for source code examples (C, fortran, or pascal)
of digital filtering. 

None of the "classic" books I have been referred to give any
program examples.

Specifically, I need a low pass filter (30-40 hz cutoff) for
a data set sampled at 100 hz. 

Does anyone have any suggestions? 


Jim Streicher
jim@heart.seas.upenn.edu


ps if this type of request does not belong in this group
please let me know. I'll search elsewhere.
From: flatau@lamar.ColoState.EDU (Piotr Flatau)
Newsgroups: sci.math.num-analysis
Subject: 2D integration on square or convex polygon, tabulated function
Date: 8 Apr 92 05:56:11 GMT
Organization: Colorado State University, Fort Collins, CO  80523

.
.
This question was asked recently, but I missed it.
I am looking for Fortran code for two-dimensional
integral. Function is tabulated (available on grid only)
and defined on square or interior of convex polygon.

Peter
 
Xref: sparky sci.math.num-analysis:1462 comp.lang.c++:6811
From: fink@think.com (Paul Fink)
Newsgroups: sci.math.num-analysis,comp.lang.c++
Subject: M++
Date: 15 Apr 1992 18:07:24 GMT
Organization: Thinking Machines Corporation, Cambridge MA, USA
Distribution: world
NNTP-Posting-Host: custard.think.com

I have heard of a mathematics library for C++ called M++.
Does anyone have any information about it?

Thanks

Paul Fink




Xref: sparky sci.math.num-analysis:1443 sci.math.stat:998
From: prasanth@gn.ecn.purdue.edu (Ravi K. Prasanth)
Newsgroups: sci.math.num-analysis,sci.math.stat
Subject: Re: Search for minimum of function of INTEGER parameters?
Keywords: simplex, parameter, function minimization
Date: 13 Apr 92 22:38:43 GMT
Followup-To: poster
Organization: Purdue University Engineering Computer Network

In article <1318@cogsci.ucsd.EDU>, miller@cogsci.ucsd.EDU (Jeff Miller) writes:
> 
> I have seen several general algorithms (eg Simplex) to search for
> parameter settings that minimize functions of real-valued parameters.
> 
> Are there also algorithms to search for settings that minimize
> functions of INTEGER-valued parameters?
> 
> Or, better yet, are there search algorithms for the case in which
> functions take both integer and real parameters?
> 
> Or is there a good trick with which a real-valued search algorithm
> (like Simplex) can be used with integer-valued parameters?
> 
> Any information relevant to this problem would be appreciated.
> 
> Jeff Miller
> Professor of Psychology
> UC San Diego
> jomiller@ucsd.edu

Genetic Algorithms can be used to find minima of any function -
functions that are real or integer valued, funtions that depend
on integer or real parameters, etc. See David Goldberg, "Genetic
Algorithms in Machine Learning" (title might be wrong). 

I have a Pascal routine that implements a simple genetic algorithm
(uses only reproduction, crossover and mutation operators). If
you need it I can email it to you.

Ravi K. Prasanth
Graduate Student
School of Aeronautics and Astronautics
Purdue University.
From: sumargoh@serss0.fiu.edu (H. Sumargo)
Newsgroups: sci.math.num-analysis
Subject: Looking for Algorithms to find Eigen-value/vector for an nxn symmetric MATRIX
Keywords: Eigenvalue
Date: 16 Apr 92 01:51:38 GMT
Organization: Florida International Univ.


I am looking for a fast algorithm to compute eigenvalue and eigenvector of a given symmetric matrix with the size of n by n.  Can someone please email to the pointer to the above solution?  thanks.
From: gdcarson@icaen.uiowa.edu (Gregory Donald Carson)
Newsgroups: sci.math.num-analysis
Subject: Need a math subroutine to....
Date: 10 Apr 92 01:23:12 GMT
Distribution: usa
Organization: Iowa Computer Aided Engineering Network, University of Iowa
Originator: gdcarson@temp2

Hello Computer and Math Guru's

	I have a problem which I hope someone can help with.  I am transporting
a very large program from VMS to Unix, one of the calls the program makes is to
a VMS FORTRAN math extension named SNLS1 or SNLS1E.  
	This routine calculates and yields the two means from a bimodal 
gaussian distribution.  What is sent to the subroutine is an array of data
points, the length of that array, and several other items of little 
importance.  What the main program expects the subroutine to do is to calculate
the two means from the assumption that the data fits a bimodal gaussian 
distribution.  The program SNLS1 uses the Levenberg-Marquardt method to find
the two means of the data, these are then returned to the program.
	What I am looking for is a program that will accomplish this task.  I
do need to be able to get the code for the program.  Does anyone have any
suggestions on a program to use.  
	Please send responses to me in mail.  Thanks in advance for your help
and for reading my post.

Greg
From: vcr+@EDRC.CMU.EDU (V C Ramesh)
Newsgroups: sci.math.num-analysis
Subject: PD NLP software ?
Keywords: PD, NLP, optimization software
Date: 10 Apr 92 22:40:57 GMT
Reply-To: vcr@cs.cmu.edu
Organization: Carnegie Mellon University

is there public domain optimization software for the general NLP problem -
non-linear objective and non-linear constraints?  i know of the
harwell library; i would like to know if there are others.

i will post a summary of responses.

thanks,
ramesh
Xref: sparky sci.math.num-analysis:1447 sci.math.symbolic:1253
From: pous@diva.Berkeley.EDU (Rafael Pous)
Newsgroups: sci.math.num-analysis,sci.math.symbolic
Subject: Matlab primer needed.
Date: 14 Apr 1992 01:41:00 GMT
Organization: University of California, Berkeley
Distribution: na
NNTP-Posting-Host: diva.berkeley.edu

I am going to use Matlab for a course in which most of the students have 
very little computer experience.  

Does anybody have a Matlab primer that I could distribute to my students?
The manual is too detailed, and I probably need permission to copy it 
anyway.  I am mostly interested in simple matrix and vector operations.

If you have it, please send it to me.  

Thank you,
			Rafael (pous@diva.berkeley.edu)
From: ky04@ns1.cc.lehigh.edu (KUN YU)
Newsgroups: sci.math.num-analysis
Subject: AX <= B  ---- HELP
Date: 10 Apr 92 00:49:53 GMT
Organization: Lehigh University


 AX=B, A=[a1 a2 a3 ... an], X=[x1 x2 x3 ...xn]' , a's and B are (mx1) vectors
                               x's are scalars.
 Known: only a1
 Sought: x1

 The problem seems ridiculous, but it does make sense and is important.
 If a1 is orthogonal to other a's,  the problem is perfectly soluble.
              x1=a1\B=a1^{+}B
 If a1 is linearly related to others, it's absolutely insoluble.

 There must be somthing between the extremes, especially if we add some
 constraints. The  physical meaning of my problem requires that nothing be
 negative, none of the elements of a's. x's and B. Thus, the problem becomes
      AX <= B,  A=[a1 a2 a3 ... an], X=[x1 x2 x3 ...xn]' ,
                     a's and B are (mx1) vectors
      rank(A)=n, A is well conditioned(not orthogonal, however).
                 All elements      of A and B are non-negative.
      Sought: X, which is all positive.

I don't know how to start the analysis.
Any advice/hints/help/references will be highly appreciated.
-- 
 
 
           /
         / _ \
       /  _I_  \
           I
         / I \
Newsgroups: sci.math.num-analysis
From: halpern@casbah.acns.nwu.edu (David Halpern)
Subject: solution method for large system of equations
Organization: Northwestern University, Evanston Illinois.
Date: Sun, 5 Apr 1992 15:09:37 GMT


Currently I'm using Gaussian elimination to solve systems of 200 or more
equations.  These systems are dense, and I have hundreds of them to solve.
What other alternatives are there such as iterative methods?

Any help  would be greatly appreciated.

David Halpern
Bioemdical  Engineering Department
Northwestern  University
From: columbus@strident.think.com (Michael Weiss)
Newsgroups: sci.math
Subject: the best known living mathematician (was: On knowing who's who)
Date: 9 Apr 92 16:31:55
Organization: Thinking Machines Corporation, Cambridge MA, USA
Distribution: na
	<COLUMBUS.92Apr9091341@strident.think.com> <a_rubin.702838383@dn66>
	<22604@dog.ee.lbl.gov> <a_rubin.702846754@dn66>
NNTP-Posting-Host: strident.think.com
In-reply-to: a_rubin@dsg4.dse.beckman.com's message of 9 Apr 92 19:12:34 GMT

In article <a_rubin.702846754@dn66> a_rubin@dsg4.dse.beckman.com (Arthur
Rubin) writes: 

   Erdos is probably the best known active mathematician, possibly the best
   known living mathematician....

Hmm... probably depends a lot on one's background.  Charlie Fefferman, Paul
Cohen, Gerd Faltings, John Milnor, Persi Diaconis.... take your pick.  Add
to the list.  (This could on for as long as "name your favorite
textbooks").

If we're talking about "best known outside the mathematics community", I
doubt that Erdos is known to, say, the average college graduate.
(Maybe he should be, but that's another question.)

A case can be made for granting Roger Penrose dual status as a
mathematician and a mathematical physicist.  He certainly has the
celebrity.

And of course, there's always Benoit Mandelbrot... (chorus of hisses, as I
cover my head to protect against brick-bats.  How many aye's do I hear for
Martin Gardner?...)
From: ender2@husc8.harvard.edu (Matt Ender)
Newsgroups: sci.math
Subject: Re: Palindrome problem
Date: 10 Apr 92 14:54:46 GMT
Article-I.D.: husc3.1992Apr10.105447.10915
Organization: Harvard University Science Center

In article <1992Apr8.150927.24607@nntp.hut.fi> jjhi@lesti.hut.fi (Jari Juhani Hiltunen) writes:
>
>I friend of mine presented me the following problem:
>
>1)  Take number i and make j out of if by reversing the order of
>    digits.
>2)  Let k=i+j.  If k is palindrome then stop.  Otherwise, let
>    i=k and go back to step 1).
>
>    i=25           25 +  52 =  77  palindrome
>
>    i=150         150 + 051 = 201  continue
>                  201 + 102 = 303  palindrome
>
>Question:  Will every number eventually yield to a number which
>is palindrome?
>
>I have tried numbers 1..200 and 196 seems to be a tough one.  A
>program of mine has already done over 100 000 iterations and the
>length of the number is currently more than 42 000 digits.

It is widely known; the base 10 case is not proven either way;
there is a sequence in base 2 that never leads to a palindrome under
the equivalent sequence.

-- Matt
From: bs@gauss.mitre.org (Robert D. Silverman)
Newsgroups: sci.math
Subject: Re: An elementary, "naturally occurring" problem
Date: 9 Apr 92 13:37:16 GMT
Article-I.D.: linus.1992Apr9.133716.24702
Organization: Research Computer Facility, MITRE Corporation, Bedford, MA

In article <michaelg.702602167@Xenon.Stanford.EDU> michaelg@Xenon.Stanford.EDU (Michael Greenwald) writes:
:bs@gauss.mitre.org (Robert D. Silverman) writes:
:
:>In article <1992Apr1.183035.14916@Princeton.EDU> carabalo@phoenix.Princeton.EDU (David G. Caraballo) writes:
:>:Prove or disprove that there exists a bijection f:[0,1] -> [0,1] that is
:>:not continuous at any point. 
:> 
:>Doesn't the following function do it?
:
:>f(x) = 1-x  if x is irrational.
:>f(x) = x if x is rational.
:
:>Bob Silverman
:
:I'll admit I'm rusty, but I'm having trouble seeing why this isn't
:continuous at x = .5.  I'm probably missing something obvious...


Yup. This has been pointed out by numerous people. However, a trivial
change fixes the objection. Just let f(1/4) = 1/2, f(1/2) = 3/4 and f(3/4) = 1/4
 
Or how about:

f(x) = (x+1/3) mod 1   if x is irrational
f(x) = (x + 2/3) mod 1 if x is rational.

--
Bob Silverman
These are my opinions and not MITRE's.
Mitre Corporation, Bedford, MA 01730
"You can lead a horse's ass to knowledge, but you can't make him think"
Newsgroups: sci.math
From: orourke@milkyway.smith.edu (Joseph O'Rourke)
Subject: Re: List of Unsolved Prime Number Problems
Organization: Smith College, Northampton, MA, US
Date: Tue, 7 Apr 1992 15:43:28 GMT

In article <1992Apr7.083752.20299@cunixf.cc.columbia.edu> 
	gd1@cunixa.cc.columbia.edu (Gautam Dalmia) writes:

>Does anyone know where I can find a list of "big open problems"
>concerning prime numbers, [...]? 

Here are two useful sources:

	"Unsolved Problems in Number Theory"
	Richard K. Guy, Springer-Verlag, 1981.

	"Old and New Unsolved Problems in Plane Geometry and Number Theory"
	Victor Klee and Stan Wagon, MAA, 1991.
From: a_rubin@dsg4.dse.beckman.com (Arthur Rubin)
Newsgroups: sci.math
Subject: Re: closed form solution to d.e.
Date: 9 Apr 92 18:52:55 GMT
Article-I.D.: dn66.a_rubin.702845575
Distribution: world
Organization: Beckman Instruments, Inc.

In <1992Apr9.042657.3710@nuscc.nus.sg> fbagohkh@nuscc.nus.sg (Mark Goh (Dr)) writes:

>Is there a closed form solution for this d.e.

>y' + a(y)^b=1, 0<a,b<1 ?

yes
--
Arthur L. Rubin: a_rubin@dsg4.dse.beckman.com (work) Beckman Instruments/Brea
216-5888@mcimail.com 70707.453@compuserve.com arthur@pnet01.cts.com (personal)
My opinions are my own, and do not represent those of my employer.
Ich bin ein Virus.  Mach' mit und kopiere mich in Deine .signature.
Newsgroups: sci.math
From: cxm7@po.CWRU.Edu (Colin Mclarty)
Subject: Re: Fermat's Last Theorem
Reply-To: cxm7@po.CWRU.Edu (Colin Mclarty)
Organization: Case Western Reserve University, Cleveland, OH (USA)
Date: Tue, 7 Apr 92 16:55:47 GMT


In a previous article, psb@remarque.berkeley.edu (psb) says:

>In article <1992Apr6.210950.26305@midway.uchicago.edu> kwhyte@zarquon.uchicago.edu (Kevin Whyte) writes:
>>  Am I the only one who thought Bob's response was tounge-in-cheek?
>>Kevin
>
>So who exactly is this guy Bob? :-)
>
>							--psb

	What I like best about this net are the really long jokes.

Colin McLarty
From: pbond@spitws100.sbil.co.uk (Philip Bond)
Newsgroups: sci.math
Subject: Re: Erdos (was Re: Fermat's Last Theorem)
Date: 14 Apr 92 09:00:47 GMT
Reply-To: pbond@spitws100.sbil.co.uk
Organization: Salomon Brothers, Ltd.

I would be interested in seeing a list of some of Erdos' problems. Can anybody
supply a few ? Many thanks.

	Philip Bond.
Xref: sparky sci.math:6068 sci.crypt:1871
From: elkies@ramanujan.harvard.edu (Noam Elkies)
Newsgroups: sci.math,sci.crypt
Subject: Re: Tangent^2 re: Mersenne
Date: 15 Apr 92 03:59:55 GMT
Article-I.D.: husc3.1992Apr14.235957.11109
Organization: Harvard Math Department

In article <1992Apr9.140121.25691@linus.mitre.org>
bs@gauss.mitre.org (Robert D. Silverman) writes:
>An expert in sieve methods tells me that if one assumes
>that there are an infinite number of p such that p and 2p+1 are both
>prime, then it is possible to show that they must be correctly 
>distributed mod 4.

Ah --- so it is a theorem after all (modulo the (p,2p+1) conjecture),
though a much harder and less familiar one than Dirichlet's on primes
in arithmetic progressions.
 
>Apparently some of Heath-Brown's recent techniques that he developed
>when he proved Artin's conjecture are relevant.

I was going to ask for more information about this last phrase, since
I was not aware that Artin's conjecture had been proved.  Since then
you have explained that you were referring to H-B's proof that Artin's
conjecture [that any positive integer k which is not a perfect r-th
power for some r>1 is a primitive residue of infinitely many primes;
sometimes one sees the special case k=2 referred to as "Artin's conjecture"]
holds for all but at most two k.  That may be a milestone in analytic
number theory (I say "may" because I'm not sufficiently familiar with
the state of the art of analytic number theory and with H-B's proof
to judge myself), but it's still not what I'd consider a proof of
Artin's conjecture, since we don't yet have a single k for which
the conjecture is known to be true --- in particular even k=2 is not
yet settled.

--Noam D. Elkies (elkies@zariski.harvard.edu)
  Department of Mathematics, Harvard University
From: bs@gauss.mitre.org (Robert D. Silverman)
Newsgroups: sci.math
Subject: Re: factoid about new prime
Date: 1 Apr 92 20:13:24 GMT
Article-I.D.: linus.1992Apr1.201324.25572
Organization: Research Computer Facility, MITRE Corporation, Bedford, MA

In article <3987@crl.LABS.TEK.COM> scott@ferrari.LABS.TEK.COM (Scott Huddleston) writes:
:It was mentioned on CNN that the new prime number discovered
:recently is four times bigger then the previous record.
:
 
This is a (slight) exaggeration. 756839/216091 = 3.5024 times as big.
--
Bob Silverman
These are my opinions and not MITRE's.
Mitre Corporation, Bedford, MA 01730
"You can lead a horse's ass to knowledge, but you can't make him think"
Newsgroups: sci.math
From: orourke@sophia.smith.edu (Joseph O'Rourke)
Subject: Re: Erdos problems
Organization: Smith College, Northampton, MA, US
Date: Fri, 10 Apr 1992 20:18:03 GMT

In article <1992Apr10.144022.10926@husc3.harvard.edu> fry@zariski.harvard.edu (David Fry) writes:
>
>There's a famous Erdos problem involving a combinatoric
>problem P for a given integer n.  Unfortunately I can't
>remember what the problem P was, other than it was deceptively
>simple. 
>[aliens story omitted]
>So does anyone know what P(n) is?

	Determination of the exact value of R(n) = R(n,n), the nth
Ramsey number?  I'm guessing.  R(n) is the smallest number of
people such that it must be that either n mutually know one another 
or n are mutual strangers.  R(3)=6 and R(4)=18, but I think R(5)
is not known.