HDTenEightyP/NetNews huggingface dataset:
From: ditolla@itnsg1.cineca.it (Francesco Di Tolla)
Subject: Re: ACCURATE frequency analysis
Keywords: Harmonic analysis 
Organization: Laboratorio di Fisica Computazionale, INFM. Trento Italia
Date: Thu, 12 Nov 1992 08:16:09 GMT

hilljr@jupiter.saic.com (Jay R. Hill) writes:

>In article <1992Nov4.172253.12871@kth.se>, pesjogre@nada.kth.se (Peter Sjogren) writes:
>|> 
>|> Given a sampled signal with a few sharp peeks in the power spectrum,
>|> what is the best method finding, AS ACCURATELY AS POSSIBLE, the 
>|> frequencies?
>|> 
>|> The approximate frequencies are known. 
>|> 
>|> 
>|> Please send answers to peter@jada.se
>|> 
>|> Thank you
>|> 
>|> Peter Sjogren
>|> Stockholm, Sweden
>|> 
>|> 
>You might check the following references:

>Hill, J. R., Long term solar activity forecasting using high-resolution
>time spectral analysis, NATURE, Vol 266, No 5598, pp 151-153, March 10,
>1977.

>Paul, A. K., Anharmonic spectral analysis (?),
>Maths Comput. 26, 437-447 (1972).

Other 2 good books has been written by: Sir L. MARPLE and 
S.KAY, both published by Mc G.  HILL, this books do present classical
methods like Periodogram and newer like ARMA-methods or MaxEnt-methods.

Bye
Franz
-- 
 --------------------------------------------------------------------------
|  Francesco  D. Di Tolla            |                                     |
|  Dip. di Fisica Univ. di Trento    | SISSA/ISAS via Beirut, 2-4          |
|  I-38050 Povo (TN)                 | I-34013 Trieste                     |
From: engrand@clt13vf.der.edf.fr
Newsgroups: sci.math.num-analysis
Subject: Automatic Time Step for an ODE
Keywords: Time Step, ODE, methods
Date: 5 Nov 92 11:05:34 GMT
Organization: EDF Direction des Etudes et Recherches


Hi there,
I just got the news here, so I don't if I can post, and, if I can, whether my question
has already been asked.

Anyway,

I'm studying different methods to automatically change the size of a time step
when solving a time-dependant ODE. Automatically means that the code should
know when it has to use a larger or smaller time step, 
according to what happens to the sytem. 

I'm interested in this problem for a general ODE first. I'd like to see
all that can be done , to be able to choose, then, which method is the most adapted
to my specific problem which is a stiff ODE.
Actually, it's a parabolic PDE (neutronic diffusion equations) on which
we apply finite volumes (or finite differences) to end up
with a time dependant system of ODE.


I'm interested in getting some references in the litterature.
I haven't heard on any book dealing with this problem (but I haven't looked
very hard) ; is there any ?

Thanks in advamce for answering,
Phil.
Newsgroups: sci.math.num-analysis
From: ciacovel@telesciences.com (Chris D Iacovelli)
Subject: Modulus 10 Check
Organization: TeleSciences CO Systems, Inc.
Distribution: usa
Date: Fri, 6 Nov 1992 16:48:57 GMT

I am in the process of designing a interface for financial institute. One of
the expected inputs will be a modulus 10 check field?

i.e.

 This is the input field 0000900000000000062.

 This translates to a number 000090000000000006 with a check digit of 2.

Any idea on how to do the appropriate checking. 

Thanks.
Chris Iacovelli
Telesciences CO Systems
Member, Technical Staff

ciacovel@telesciences.com
From: 4er@stretto.iems.nwu.edu (Robert Fourer)
Newsgroups: sci.math.num-analysis
Subject: optimization modeling language
Keywords: optimization, mathematical programming
Date: 10 Nov 92 00:33:59 GMT
Reply-To: 4er@nwu.edu (Robert Fourer)
Organization: Industrial Engineering and Management Sciences Department, Northwestern University, Evanston, IL


Since this newsgroup periodically receives requests for 
information on optimization (or mathematical programming) 
software, I am posting the following brief announcement 
of the availability of a new package.

The AMPL language for describing optimization problems to
computer systems was introduced in Management Science 36
(1990) 519-554, and has also been described in many 
conference talks over the past five years.  A complete 
tutorial and reference for AMPL is now available in:

   AMPL: 
   A Modeling Language 
   for Mathematical Programming

   by Robert Fourer, David M. Gay and Brian W. Kernighan

This book is packaged with a 300 x 300 MS-DOS version of the
AMPL language processor and the MINOS and CPLEX optimizers.
It covers linear, network, integer and nonlinear programming,
and is suitable for instructional use or evaluation of the
software.  A variety of other combinations of operating
systems and optimizers are also supported.

Additional information is available from The Scientific
Press at (800) 451-5409 or (415) 583-8840.
Newsgroups: sci.math.num-analysis
From: ramesh@MV3600.BMEN.TULANE.EDU
Subject: nonlinear wave equation on a sphere
Reply-To: ramesh@MV3600.BMEN.TULANE.EDU
Organization: TULANE, BMEN, NEW ORLEANS, LA
Date: Wed, 11 Nov 1992 17:43:56 GMT
Nntp-Posting-Host-[nntpd-23077]: bpbme.bmen.tulane.edu

	I was wondering about how one numerically solves a nonlinear pde 
(like the wave equation, or a nonlinear Helmholz equation) on a closed
object like a sphere.  

	My previous experience has been that a spectral method (like
ORSZAG) is required.  This is eeasy to do using Fourier series and the
appropriate trignoetric identities.  However, on a sphere, sphereical harmonics
have to be used, for which there aren't the same type of identities.
	
	Does anyone know how to set up a finite difference scheme for a 
closed object like a sphere?

				Thanks,

				Ramesh Srinivasan
				ramesh@mv3600.bmen.tulane.edu
Newsgroups: sci.math.num-analysis
From: hilljr@jupiter.saic.com (Jay R. Hill)
Subject: Re: ACCURATE frequency analysis
Keywords: Harmonic analysis 
Organization: SAIC 
Date: Wed, 11 Nov 1992 01:00:12 GMT

In article <1992Nov4.172253.12871@kth.se>, pesjogre@nada.kth.se (Peter Sjogren) writes:
|> 
|> Given a sampled signal with a few sharp peeks in the power spectrum,
|> what is the best method finding, AS ACCURATELY AS POSSIBLE, the 
|> frequencies?
|> 
|> The approximate frequencies are known. 
|> 
|> 
|> Please send answers to peter@jada.se
|> 
|> Thank you
|> 
|> Peter Sjogren
|> Stockholm, Sweden
|> 
|> 
You might check the following references:

Hill, J. R., Long term solar activity forecasting using high-resolution
time spectral analysis, NATURE, Vol 266, No 5598, pp 151-153, March 10,
1977.

Paul, A. K., Anharmonic spectral analysis (?),
Maths Comput. 26, 437-447 (1972).
From: stewart@cs.umd.edu (G. W. Stewart)
Newsgroups: sci.math.num-analysis
Subject: Re: Code for Rank Revealing QR Factorizations
Date: 13 Nov 92 08:24:05 GMT
Article-I.D.: mimsy.62019
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742

In article <1992Nov12.215633.8030@cis.uab.edu> katholi@willis.cis.uab.edu (C.R. Katholi) writes:
>
>     I think that I saw a notice somewhere not too long ago concerning
>an implementation of the rank revealing QR factorization described by
>T. Chan, "Rank Revealing QR Factorizations", Linear Algebra and Its
>Applications, (1987). Can anyone point me to a place where I can obtain this
>code, preferably by ftp. Please send responses to   katholi@cis.uab.edu.
>     Thank you in advance for your help. 

There have been developments since Tony published his RRQR factorization.
I have written a survey "Determining Rank in the Presence of Error,"
which can be obtained by anonymous ftp at thales.cs.umd.edu in
pub/reports.  The file is drpe.dvi (remember to transfer in the binary
mode).  Experimental FORTRAN code for a RRURV decomposition can be
found in uast.f.  You also might want to try browsing through the
Abstracts or Contents file for related reports.

Pete Stewart
From: frederik@pollux.acs.uci.edu (M. Donald Frederick)
Subject: Re: Laplace Transform
Newsgroups: sci.math.num-analysis
Reply-To: frederik@pollux.acs.uci.edu (M. Donald Frederick)
Organization: University of California, Irvine
Keywords: Relaxation Spectrum
Date: 7 Nov 92 00:01:57 GMT

In article <6601@news.duke.edu>, fang@phy.duke.edu (Fang Zhong) writes:
|> 
|> 	After informed by a netter, I want to make clearer on my
|> earlier post.
|> 	Yes, we want the time constants in the sum of exponentials,
|> it is basically "relaxation spectrum" analysis as analogous to FFT
|> in "frequency spectrum".
|> 	We tried to use nonlinear fit of multiple exponentials to
|> fit our data, the results were not very good.  So we thought about
|> the Laplace Transform.
|> 	As I was informed, people studying NMR relaxation prcesses
|> already developed certain technique for the analysis.
|> 	Is it available from any ftp site?
|> 	Is there a FLT as to FFT?
|> 	Thanks in advance for helps.
|> 
|> -- 
|> 	Fang Zhong				1-919-660-2524
|> 	Duke University Dept. of Physics	fang@phy.duke.edu
|> 	Durham, N.C.      27706			

I don't know anything about the NMR-related algorithms (although you might
want to follow the thread on Nonlinear Least-Squares on this board), however,
the same problem crops up elsewhere, in system identification, etc. One old
reference is Chapter 11 of "Digital Spectral Analysis", by S. Marple. This
chapter is concerned with "Prony's Method" - fitting damped sinusoids to
a time series. The book includes a Fortran program. As I recall, the method
works well with low-noise data, but as S/N decreases, a big problem is
determining the number of sinusoids present. 


------------------------------------------------------------------------
        Donald Frederick       |      Office of Academic Computing
        frederik@uci.edu       |      University of California, Irvine
        frederik@UCI.BITNET    |      Irvine, CA  92717
        (714) 725-3200         |      FAX (714) 725-2069
-----------------------------------------------------------------------
Newsgroups: sci.math.num-analysis
From: jingjun@leland.Stanford.EDU (Jingjun Cao)
Subject: wanted: ftp site for multiprecision (in C and Fortran )
Organization: DSG, Stanford University, CA 94305, USA
Date: Thu, 5 Nov 92 22:58:51 GMT

Hi, everyone,

I am computing a perturbation problem and facing a serious erosion of 
accuracy. I am working on sparc workstations and using both C and Fortran.
I have heard that there are certain software (or library) that allows one
to have multiprecision(say, 40 significant digits) in carrying out the 
computation.

Could some knowledgable people there please inform me how to get and use
it? 

Thank you very very much.

Jingjun Cao
Division of Applied Mechanics
Department of Mechanical Engineering
Stanford University
From: 4er@stretto.iems.nwu.edu (Robert Fourer)
Newsgroups: sci.math.num-analysis
Subject: optimization modeling language
Keywords: optimization, mathematical programming
Date: 10 Nov 92 00:20:16 GMT
Reply-To: 4er@nwu.edu (Robert Fourer)
Organization: Industrial Engineering and Management Sciences Department, Northwestern University, Evanston, IL


Since this newsgroup periodically receives requests for 
information on optimization (or mathematical programming) 
software, I am posting the following brief announcement 
of the availability of a new package.

The AMPL language for describing optimization problems to
computer systems was introduced in Management Science 36
(1990) 519-554, and has also been described in many 
conference talks over the past five years.  A complete 
tutorial and reference for AMPL is now available in:

   AMPL: 
   A Modeling Language 
   for Mathematical Programming

   by Robert Fourer, David M. Gay and Brian W. Kernighan

This book is packaged with a 300 x 300 MS-DOS version of the
AMPL language processor and the MINOS and CPLEX optimizers.
It covers linear, network, integer and nonlinear programming,
and is suitable for instructional use or evaluation of the
software.  A variety of other combinations of operating
systems and optimizers are also supported.

Additional information is available from The Scientific
Press at (800) 451-5409 or (415) 583-8840.
From: jwg@sparcman.cray.com (John Gregory)
Newsgroups: sci.math.num-analysis
Subject: Re: Is there any PD optimization package for integer programming?
Keywords: optimization, integer programming
Date: 12 Nov 92 22:07:35 GMT
Reply-To: jwg@sparcman.cray.com (John Gregory)
Organization: Cray Research, Inc.


In article <Q-C=hc-@engin.umich.edu>, sglee@engin.umich.edu (Soon Geul Lee) writes:
|> Hello,
|> 
|> Is there any program routine or package for integer optimization problem?
|> I prefer one written with 'C', but it doesn't matter with 'Fortran'.
|> Please mail me.

It having been a few weeks since I lasted posted the Linear Programming
FAQ List, I will post it today in a separate article (an ulterior motive
being to try to finally succeed in cross-posting it to news.answers).  
Hope it helps you.

- John
Newsgroups: sci.math.num-analysis
From: maawg@marlin.jcu.edu.au (Andrew Gill)
Subject: Arnoldi Method
Organization: James Cook University
Date: Fri, 13 Nov 92 00:39:09 GMT

Hi.  Can anyone give me some textbook references to the Arnoldi method
for eigenvalue compuatation ?  I have a complex matrix and want that
eigenvalue with the largest imaginary part. 

ADVthanksANCE

Andrew Gill
maawg@marlin.jcu.edu.au
Newsgroups: sci.math.num-analysis
From: sglee@engin.umich.edu (Soon Geul Lee)
Subject: Is there any optimazation package for integer programming?
Date: Wed, 11 Nov 92 17:36:08 EST
Organization: University of Michigan Engineering, Ann Arbor
Keywords: optimization, integer programming


Is there any PD or shareware optimization routine or package for integer
programming?  I need C or Fortran routine (I prefer C routine.).
Please mail me.

Thanks in advance.

---------------------------------------------------------------------------
 MEAM    Soon Geul Lee			sglee@caen.engin.umich.edu
BIOMECH  (313) 936-0367,763-2272 (Day)
 UOFM    (313) 763-8762 (Home)
---------------------------------------------------------------------------
From: phd85@keele.ac.uk (D.H. Holden)
Newsgroups: sci.math.num-analysis
Subject: S statistical package.
Date: 11 Nov 92 13:06:34 GMT
Organization: Keele University, England


 Hi,
     I've got a package from the netlib called xgobi, and this
     talks about a package called S. 
     Does anyone know what this is, and where I can get a copy.
     I've seen a directory called S on various anon ftp sites but
     these just seem to be various other packages that use S.

	Thanks in advance,
					   Dave.


--
                                                                     

phd85@uk.ac.keele.seq1
keele university. 
Newsgroups: sci.math.num-analysis
From: collins@eol.ists.ca (Mike Collins)
Subject: matlab routine for levenberg-marquardt
Organization: Earth Observations Laboratory, ISTS
Date: Fri, 6 Nov 92 23:27:32 GMT

  I am trying to fit a non-linear function to some
experimental measurements. has anyone written a 
matlab function to perform the levenberg-marquardt
method (i'm thinking of the one in numerical
recipes). i looked around on netlib, but couldn't
find anything. 

cheers
mjc

-- 
michael collins
institute for space and terrestrial science
toronto, canada M3J 3K1
collins@eol.ists.ca
Newsgroups: sci.math.num-analysis
From: yzhang@math15.math.umbc.edu (Yin Zhang)
Subject: Re: Non-linear Inequality Constraint
Organization: University of Maryland Baltimore Campus
Date: Thu, 5 Nov 1992 22:39:19 GMT

In article <1992Nov5.195334.774@qucis.queensu.ca> 
ismaeil@qucis.queensu.ca (Ossama Ismaeil) writes:
>
>                  T
>           Min   X  X  
>
>      S.T         T 
>                 X A X <= 0
>                
>  wher X is a vector and A is a square indefinite matrix.

X = 0 is THE solution to the above problem.
From: warsa@polaris.unm.edu (j warsa)
Newsgroups: sci.math.num-analysis
Subject: Gauss/Lobatto Quadrature Code
Date: 11 Nov 92 15:35:32 GMT
Article-I.D.: lynx.+kcqmdd
Followup-To: sci.math.num-analysis
Organization: Universidad de Nuevo Mexico, Alburquerque

In the past several years, I have seen maybe ten or twenty requests for
Gauss quadrature generating codes, and related things like numerical 
integration programs. I have written FORTRAN codes that generate the
Gauss and Lobatto quadratures, and other codes that perform 1- and 2-D 
integration using these quadratures. In response to several of the requests,
I mailed these programs directly to those who asked. 

Becuase of the numerous requests for such programs, I thought that there may 
not be any available in the traditional math library archives (like netlib, 
etc.). I was wondering if anyone in this group could tell me what is available,
and whether I should make my codes available to others via netlib, or some 
other software repository. If you think I should, what is the procedure for 
doing so?

Thanks.
-- 
jim warsa
albuquerque
From: fred@poly2.nist.gov (Frederick R. Phelan Jr.)
Newsgroups: sci.math.num-analysis
Subject: Re: polynomial root finding
Date: 6 Nov 92 20:18:53 GMT

In article <1992Nov5.175007.3406@news2.cis.umn.edu>, jblee@giga.cs.umn.edu (Jaebum Lee) writes:
|> Hi,
|> I am looking for a subroutine to find all the roots(including complex) of
|> a polynomial with real coefficients. Does anybody out there have such a
|> subroutine? Any pointers wiil be appreciated.
|> 
|> Jaebum Lee
|> jblee@tera.cs.umn.edu
|>   

Look for the algorithm zroots in NUMERICAL RECIPES by Press, Flannery et al.
Works very nicely.


Fred
---
Fred Phelan
fred@poly2.nist.gov
/*___________________________________________________
   ____ __  ___  __    ___       ___        ___ 
  /__  /_/ /__  / /   /__/ /__/ /__   /    /__/ /\  /  
 /    / ( /__  /_/   /    /  / /___  /___ /  / /  \/
___________________________________________________*/
From: hblim@iti.gov.sg (Hock-Beng Lim)
Newsgroups: sci.math.num-analysis
Subject: 32-bit vs 64-bit precision ?
Date: 6 Nov 92 03:37:54 GMT
Organization: Information Technology Institute, National Computer Board, Singapore.

Hi !

I am new to this newsgroup and so I don't know if my question is a FAQ.

I would like to know more about how the properties of numerical algorithms
will impact the choice of whether to implement them in 32-bit or 64-bit
precision floating-point arithmetic. The main classes of algorithms I am
interested in are linear system solvers and eigensolvers. 

Please send me your comments and experiences. I will post a summary if
there is sufficient interest on this subject.

Thanks in advance !

HB
-- 
-----------------------------------------------------------------------------
Hock-Beng Lim                                   | hblim@csrd.uiuc.edu
Center for Supercomputing R&D, UIUC. (on leave) | hblim@iti.gov.sg 
Information Technology Institute, Singapore.    | tel : (65)772-7205,772-7273
From: dch@comlab.ox.ac.uk (David Handscomb)
Newsgroups: sci.math.num-analysis
Subject: Re: Non-linear Inequality Constraint
Date: 12 Nov 92 18:18:22 GMT
Organization: Oxford University Computing Laboratory, UK
Originator: dch@nagp12.comlab

In article <1992Nov6.170030.8063@qucis.queensu.ca> ismaeil@qucis.queensu.ca (Ossama Ismaeil) writes:
>
>   Now, the problem can be described as 
>
>                  T
>           Min   X  X  
>
>      S.T         T 
>                 X A X <= 0
>
>                 W X    = C   
>
>  where X is a vector , A is a square indefinite matrix, and W is a rectangular
>  matrix, and C is a constant vector.
>

(Assume that A is symmetric and W is of maximal rank.)

Write Y = W^T (W W^T)^{-1} C.  If Y^T A Y <= 0, then X = Y is the answer.

Otherwise, the answer will have X^T A X = 0.

Let Q be a rectangular matrix whose rows are are maximal set of orthonormal 
vectors orthogonal to the rows of W.  Then W X = C if and only if X is of the 
form Y + Q Z, where the vector Z is in 1-1 correspondence with X.

So we want to minimize X^T X - Y^T Y = Z^T Z given that 
    X^T A X = Z^T Q^T A Q Z + 2 Y^T A Q Z + Y^T A Y = 0.

Find the eigensystem of (Q^T A Q) and expand Z in terms of the eigenvectors.  
Then we can transform the problem into minimizing Sum_i (z_i^2) given that 
Sum_i (a_i z_i^2) + 2 Sum_i (b_i z_i) + c = 0.

The solution to this is z_i = lambda b_i / (1 - lambda a_i), where lambda is
one of the roots of a polynomial equation, got by substituting this z_i into
the given condition.  Hence Z, hence X.

David Handscomb
(dch@comlab.ox.ac.uk)
From: dodd@mycenae.cchem.berkeley.edu (Lawrence R. Dodd)
Newsgroups: sci.math.num-analysis
Subject: Re: Euler's *Theorem* Proof?
Date: 11 Nov 92 06:19:33
Organization: Dept of Chemical Engineering, Polytechnic Univ, NY, USA
Distribution: inet
Reply-To: dodd@roebling.poly.edu
NNTP-Posting-Host: mycenae.cchem.berkeley.edu
In-reply-to: fsrmh1@acad3.alaska.edu's message of 10 Nov 92 18:30:28 GMT


>>>>> "fsrmh1" == fsrmh1  <fsrmh1@acad3.alaska.edu> writes:

  fsrmh1> Who Proved Euler's *Theorem*?

which one?
From: keith@msmri.med.ubc.ca (Keith S Cover)
Newsgroups: sci.math.num-analysis
Subject: Re: Laplace Transform
Date: 7 Nov 1992 22:05:01 GMT
Organization: University of British Columbia, Vancouver, B.C., Canada
Distribution: inet
NNTP-Posting-Host: msmri.med.ubc.ca
Keywords: Relaxation Spectrum

Besides NMR relaxation measurements what other areas need 
numerical inverse Laplace Transforms?

Keith S Cover
Physics, UBC
Vancouver, B.C.
Canada
keith@msmri.med.ubc.ca

Newsgroups: sci.math.num-analysis
From: bergstrm@casbah.acns.nwu.edu (Todd Bergstrom)
Subject: Finite Elements
Organization: Northwestern University, Evanston Illinois.
Distribution: sci.math.num-analysis
Date: Wed, 11 Nov 1992 21:25:57 GMT

I am looking for a public domain finite element program with its code.  Can
anyone suggest a site to FTP or another way to obtain one.

Thanks in advance

email bergstrm@casbah.acns.nwu.edu

Newsgroups: sci.math.num-analysis
From: cwillits@afit.af.mil
Subject: Scheeffer-Stolz-Van Dantsher Method
Organization: Air Force Institute of Technology
Date: Sat, 7 Nov 1992 07:30:08 GMT

Does anyone out there have a FORTRAN program/subroutine/code fragment which 
uses the Scheeffer-Stolz-Van Dantsher method to classify the stationary points 
of a multivariate function?

I need this for a first-year graduate course in operations research.  I could
probably write it myself, but time is of the essence.

I'd prefer ANSI, VMS or Microsoft FORTRAN, but will take any dialect as long as
I'm told the mods I need to make to get it to compile using a VMS or MS FORTRAN
compiler.

Direct e-mail replies are welcome.

Many thanks in advance--

Craig Willits
cwillits@afit.af.mil
Newsgroups: sci.math.num-analysis
From: barry@arnold.math.ucla.edu (Barry Merriman)
Subject: Re: Automatic Time Step for an ODE
Organization: UCLA, Mathematics Department
Date: Sun, 8 Nov 92 01:08:47 GMT

In article <KJELL.92Nov6120116@sccm.Stanford.EDU> kjell@sccm.Stanford.EDU  
(Kjell Gustafsson) writes:
> I've studied this problem in my thesis "Control of Error and
> Convergence in ODE Solvers", Kjell Gustafsson, Department of Automatic
> Control, Lund Institute of Technology, Sweden, 1992". It turns out
> that with some ideas from feedback control you can get a better
> understanding of the stepsize adjustment problem and also design
> improved algorithms. 

Step control is usually based on simple trial-and-error, plus
an assumed asymptotic form for the time step error term. 

Does applying control theory to such a simple situation really
lead to algorithms that are more _efficient_ for typical 
problems?

--
Barry Merriman
UCLA Dept. of Math
UCLA Inst. for Fusion and Plasma Research
barry@math.ucla.edu (Internet; NeXTMail is welcome)


Newsgroups: sci.math.num-analysis