HDTenEightyP/NetNews huggingface dataset:
From: neilfp@astro.ocis.temple.edu (Neil F. Palumbo)
Newsgroups: sci.math.num-analysis
Subject: XAY+XB+CY+D=0, HELP
Date: 10 Sep 92 13:56:54 GMT
Organization: Temple University
X-Newsreader: Tin 1.1 PL5

I am trying to solve the matrix equation XAY+XB+CY+D=0 analytically for the
unknown matrices {X,Y}. Anyone have any ideas, suggestions, comments ...?
From: izumi@mindseye.berkeley.edu (Izumi Ohzawa)
Newsgroups: sci.math.num-analysis
Subject: Re: The IMHO Riddle
Date: 11 Sep 1992 07:46:04 GMT
Organization: /etc/organization
Distribution: inet
NNTP-Posting-Host: mindseye.berkeley.edu

In article <BuE8J7.998@me.utoronto.ca> 
 steinman@me.utoronto.ca (David Steinman) writes:
>frandsen@seismo.CSS.GOV (Marvin Vaun Frandsen) writes:
>>Just what does "IMHO" mean?  Thanks
>IMHO == In My Humble Opinion

Sure, and why is it that I find least humbleness in
opinions prefixed with IMHO?

It's my #1 kill word.


-- 
Izumi Ohzawa             [ $BBg_78^=;(B ]
USMail: University of California, 360 Minor Hall, Berkeley, CA 94720
Telephone: (510) 642-6440             Fax:  (510) 642-3323
Internet: izumi@pinoko.berkeley.edu   (NeXTmail OK)
Newsgroups: sci.math.num-analysis
From: steinman@me.utoronto.ca (David Steinman)
Subject: Re: The IMHO Riddle
Organization: UofT Mechanical Engineering
Date: Fri, 11 Sep 1992 03:04:18 GMT

frandsen@seismo.CSS.GOV (Marvin Vaun Frandsen) writes:

>Just what does "IMHO" mean?  Thanks

IMHO == In My Humble Opinion
--
Dave!
Newsgroups: sci.math.num-analysis
From: fsjm@steelhead.lerc.nasa.gov (Joseph Mathew)
Subject: Re: Oscillatory Integration?
Organization: NASA Lewis Research Center [Cleveland, Ohio]
Date: Sat, 5 Sep 1992 02:19:42 GMT

In article <92247.091826J0S@psuvm.psu.edu> J0S@psuvm.psu.edu (Jack W. Sharer) writes:
>I'm having to evaluate this integral:
>
>          /\ 0.5
>         /           N
>        /      f(x) D (2 pi x + phi) dx
>       /
>     \/ -0.5
>
>                       N
>for N ~ 500 and where D (x) is the N-point Dirichlet kernel:
>
>
>               iNx
>       N      e    - 1
>      D (x) = --------,  i = sqrt(-1)   (highly oscilatory for large N)
>                ix
>               e  - 1
>
>I'm successfully using a 2000-point Simpson integration, but I cannot
>begin to evaluate all the needed cases (limited by computer resources).
>
>Could you suggest a change of variable or another technique which
>would dramatically improve the integration speed?

	Since D(x;N) = 1 + exp(ix) + exp(2ix) + ... + exp((N-1)ix)
aren't you just looking for the sum of the Fourier coefficients?

Joseph Mathew
From: herman@nosc.mil (John W. Herman)
Newsgroups: sci.math.num-analysis
Subject: Re: Fourier series approximation
Date: 8 Sep 92 20:04:35 GMT
Organization: Naval Ocean Systems Center, San Diego, CA

rh@smds.com (Richard Harter) writes:

>In article <Bu6CKC.6tF@me.utoronto.ca> steinman@me.utoronto.ca (David Steinman) writes:
>>kavuri@lips.ecn.purdue.edu (Surya N Kavuri ) writes:

>>>  When the data is NOT sampled at regular intervals, how are the fourier
>>>  coefficients determined ?

>>Well, it may not be pretty (or even that accurate), but I usually just
>>integrate the coefficient integrals using a trapezoidal rule.  

>There are three cases of interest that I can think of:

Look at the definition of the Discrete Fourier Transform.  Before
simplification, it contains the time as an explicit variable.  Try this
first with a finite length window (read finite number of samples).
From: pal@angelo.amd.com (P.A.L)
Newsgroups: sci.math.num-analysis
Subject: Re: pi to as many places as you want.
Date: 15 Sep 92 16:55:54 GMT
Organization: Advanced Micro Devices, Inc; Sunnyvale, CA

In article <92258.145152RVESTERM@vma.cc.nd.edu> RVESTERM@vma.cc.nd.edu writes:
>arccos(-1).

That is not true.  It is limited by your computational machine.
From: perkins@sousa.ltn.dec.com (Eric Perkins)
Newsgroups: sci.math.num-analysis
Subject: Computing PI:
Date: 8 Sep 92 17:44:19 GMT
Reply-To: perkins@sousa.ltn.dec.com (Eric Perkins)
Organization: Digital Equipment Corporation, Littleton MA


There was an article posted a while back asking for an infinite 
PI program. Did anyone have such a program ? The sender said to
reply by mail, but if someone has such a program could they just
post it here?

Also, does someone have a way to verify that PI to x number of 
digits is correct. Lets say I have a file with a sequence of numbers
how can I prove that these are  indeed PI?

-- Eric Perkins
-- perkins@tallis.enet.dec.com
From: joe@degsyd.syd.deg.csiro.au
Newsgroups: sci.math.num-analysis
Subject: help finding minimum volume simplex ?
Date: 10 Sep 92 12:08:53 +1000
Organization: CSIRO, Exploration Geoscience

G'day,
  I am working on a problem that requires fitting a simplex around a set of
data points in n-dimensions.  In other words, I have a set of
n-dimensional points and I'd like to find the smallest (least "volume") n-d
simplex (n+1 verices) that contains these points in its interior.  Any pointers
to previous work or ideas on how you have attacked similar problems would be
appreciated.  I am currently thinking of the problem in the light of linear
programming, where I'm trying to find the constraints (the bounding 
hyperplanes) given these interior points. For instance : 

In 2-d my simplex will be a triangle formed by three hyperplanes (lines).
I need to find the three lines that each separate the 2-d space into two
halfspaces (one with all my data and one with none), and together form the
triangle of minimum area that contain my data. And of course I want this to be
generalized to any dimension, be robust, easy to code, not memory intensive,
make me breakfast and wash my car :) 

Hope to hear from you soon.

Joe

-- 
-
JOSEPH WILLIS BOARDMAN
Email: joe@syd.deg.csiro.au
Phone: 61-2-887-8884
From: pal@angelo.amd.com (P.A.L)
Newsgroups: sci.math.num-analysis
Subject: PI Question
Date: 12 Sep 92 21:07:11 GMT
Organization: Advanced Micro Devices, Inc; Sunnyvale, CA

What is an infinite series for PI (3.14.....)?  An equation is prefered.
With the above eqation, is it possible to write a c program to find out 
what is the number after xth decimal place, where x > 0.  Please response
via email.  Thanks in advance.

Paul
Newsgroups: sci.math.num-analysis
From: jacquet@cmu.unige.ch
Subject: Statistical Tools in MATLAB
Organization: University of Geneva, Switzerland
Date: Fri, 11 Sep 1992 08:20:28 GMT

Hello,

I'm interested in a Tools of statistical tests (nonparametric) written in
MATLAB.

Thanks in advance

--
J.JACQUET                                   +4122.347.33.34 (Fax)
Centre Medical Universitaire                +4122.705.50.71 (office)
Service Informatique                         jacquet@cmu.unige.ch
1, rue Michel-Servet
1211 Geneva / Switzerland
From: dak@tabaqui.informatik.rwth-aachen.de (David Kastrup)
Newsgroups: sci.math.num-analysis
Subject: Re: Distributed Random Number Generation
Date: 13 Sep 92 12:29:14 GMT
Organization: Rechnerbetrieb Informatik  /  RWTH Aachen

daveg@synaptics.com (Dave Gillespie) writes:

>In article <h_8yzkk@rpi.edu> maniattb@cs.rpi.edu (Bill Maniatty) writes:
>> I have a large distributed stochastic model (runs on MasPar MP-1 with 2,048
>> processing elements).  I'm not an expert on random number generation, but
>> I need to simultaneously g enerate different ``Random'' sequences on each
>> node.

>If the nodes must be independent, then it would probably work pretty
>well to use one random number generator, say, linear congruential,
>to create a sequence of 2048 seeds for a different type of generator,
>say additive congruential, running in parallel on the various nodes.

This idea is really bad, because it ensures that no two generators will
give the same number at one moment (or even always the same). Besides, random
number generators are usually not designed to produce uncorrelated
numbers at ARBITRARY distances in their sequence, so you would probably
fail even simple tests terribly. As I said before, the only mathematically
safe way is to use ONE (and only one) generator of very high quality to
produce values in turn. This is because the mathematics for a good RNG
can only be ensured with regard to itself, not to other instances of it
(different seeds), and certainly not to different RNGs without further
information.
Newsgroups: sci.math.num-analysis
From: ppc1@cec1.wustl.edu (Peter Pui Tak Chiu)
Subject: Differential Eqts
Organization: Washington University, St. Louis MO
Date: Sun, 6 Sep 1992 22:15:56 GMT

hi everyone,

i have been trying to plot the direction field of y'=-xy for an hour
using Mathematica.  i have the book by wolfram but still can't figure 
out how.  can anyone please give me a hand?

thanks in advance

pete
From: fortuna@cs.man.ac.uk (Armando Fortuna)
Newsgroups: sci.math.num-analysis
Subject: mesh generation for CFD
Date: 14 Sep 92 09:19:27 GMT
Organization: Dept Computer Science, University of Manchester, U.K.

Hello everyone,

I am looking for a program which lets you generate/visualize a mesh
pattern over a domain. I intend to use it for CFD calculations. 

Is there any PD package available? If not, what are the proprietary ones?

Thanks,
Armando

--
===========================================================================
Armando de Oliveira Fortuna                    E-mail: fortuna@cs.man.ac.uk
Dept. of Computer Science                      Tel.: +44 61 275-6132
University of Manchester                       Fax.: +44 61 275-6204
Oxford Road
Manchester M13 9PL                          "...It works better...
England                                             ...if you plug it in..."
============================================================================
All opinions expressed are mine only! If you think otherwise, think it over!
Newsgroups: sci.math.num-analysis
From: steinman@me.utoronto.ca (David Steinman)
Subject: Re: Fourier series approximation
Organization: UofT Mechanical Engineering
Date: Sun, 6 Sep 1992 20:50:36 GMT

kavuri@lips.ecn.purdue.edu (Surya N Kavuri ) writes:

>  When the data is NOT sampled at regular intervals, how are the fourier
>  coefficients determined ?

Well, it may not be pretty (or even that accurate), but I usually just
integrate the coefficient integrals using a trapezoidal rule.  
--
Dave!
Newsgroups: sci.math.num-analysis
From: maniattb@cs.rpi.edu (Bill Maniatty)
Subject: Re: Distributed Random Number Generation
Date: Sun, 13 Sep 1992 21:57:40 GMT

In article <dak.716387354@tabaqui>, dak@tabaqui.informatik.rwth-aachen.de (David Kastrup) writes:
|> daveg@synaptics.com (Dave Gillespie) writes:
|> 
|> >In article <h_8yzkk@rpi.edu> maniattb@cs.rpi.edu (Bill Maniatty) writes:
|> >> I have a large distributed stochastic model (runs on MasPar MP-1 with 2,048
|> >> processing elements).  I'm not an expert on random number generation, but
|> >> I need to simultaneously g enerate different ``Random'' sequences on each
|> >> node.
|> 
|> >If the nodes must be independent, then it would probably work pretty
|> >well to use one random number generator, say, linear congruential,
|> >to create a sequence of 2048 seeds for a different type of generator,
|> >say additive congruential, running in parallel on the various nodes.
|> 
|> This idea is really bad, because it ensures that no two generators will
|> give the same number at one moment (or even always the same). Besides, random
|> number generators are usually not designed to produce uncorrelated
|> numbers at ARBITRARY distances in their sequence, so you would probably
|> fail even simple tests terribly. As I said before, the only mathematically
|> safe way is to use ONE (and only one) generator of very high quality to
|> produce values in turn. This is because the mathematics for a good RNG
|> can only be ensured with regard to itself, not to other instances of it
|> (different seeds), and certainly not to different RNGs without further
|> information.

The problem with this solution as I see it is that it eliminates any parallelism
I might have in my program.  Please remember that there is a LARGE number of
random number generated (2048) for each time step.  It seems that making each
time step wait for all 2048 random numbers to be generated is terribly
inefficient (wait to generate 2047 random numbers never used by this processor).

Can you tell me just what sort of metrics are used to determine ``randomness'',
and suggest some solutions/references (can a sequential algorithm be extended
to operate in parallel? can a parallel algorithm be developed directly with any
reasonable degree of confidence?)

Thanks for your help,

Bill
-- 
|
|	maniattb@cs.rpi.edu - in real life Bill Maniatty
|
From: frandsen@seismo.CSS.GOV (Marvin Vaun Frandsen)
Newsgroups: sci.math.num-analysis
Subject: The IMHO Riddle
Date: 11 Sep 92 01:28:49 GMT
Organization: Center for Seismic Studies, Arlington, VA

This may be a strange place, but its probably as good as any ...

Just what does "IMHO" mean?  Thanks

-- Marv Frandsen   frandsen@beno.css.gov
From: tibbits@sisal.llnl.gov (Patrick Tibbits)
Newsgroups: sci.math.num-analysis
Subject: Re: Polygon in or out?
Date: 11 Sep 92 03:49:04 GMT
Organization: Lawrence Livermore National Laboratory

I acknowledge my error the polygon must be convex for my 
suggestion to work.

Patrick
Newsgroups: sci.math.num-analysis
From: kdorma@ravana.eche.ualberta.ca (Kevin Dorma)
Subject: need help using sparse (C)
Organization: Dept. of Chemical Engineering, University of Alberta
X-Newsreader: Tin 1.1 PL3
Date: Sun, 13 Sep 1992 18:37:27 GMT

Hi,
I'm trying to solve a simple sparse matrix problem in C using "sparse".
Just real numbers, nothing fancy.  Haven't had any luck trying to get
the thing to work.  Could some kind soul please show me how to put the 
coefficients into the matrix and create the RHS vector?

TIA

                                  | 
Kevin Dorma                       | Hi, my Lyapunov exponent is 2.31.
kdorma@ravana.eche.ualberta.ca    | What's yours?
Ph.D. type of student             | 
Dept. of Chemical Engineering     | Don't look at my disclaimer, your's
University of Alberta             | is much more interesting.
Edmonton, Alberta                 | 
                                  |
From: tmw@festival.ed.ac.uk (Tom WRight)
Newsgroups: sci.math.num-analysis
Subject: numerical recipes: fft in 3d
Date: 8 Sep 92 19:04:38 GMT
Distribution: sci

Has anybody had any trouble using the subroutine fourn.dat in 3 
dimensions

Could anybody recommend another  routine ?


Thanks
Newsgroups: sci.math.num-analysis
From: ramesh@MV3600.BMEN.TULANE.EDU
Subject: root-finding
Nntp-Posting-Host-[nntpd-6566]: bpbme.bmen.tulane.edu
Reply-To: ramesh@MV3600.BMEN.TULANE.EDU
Organization: TULANE, BMEN, NEW ORLEANS, LA
Date: Fri, 11 Sep 1992 04:43:32 GMT

I have been trying to find the roots of the following complex valued dispersion
relation for its complex roots w:

1 - b*((j*(m-w)+x)*(1-exp(-x+j*(m-w))) + (-j*(m+w)+x)*(1-exp(-(x+j*(m+w)))) =0
        _____________________________      _______________________________
                  (m-w)**2+x**2                     (m+w)**2+x**2


I have been able to find roots for x large and positive (dropping the exponent)
but i don't have any result for a general solution

Another way to write this is to let w = u + j*d where u and d  are real.  Then
substituting we obtain two equations for the unknowns u and d.  Howver this
does not really help, all it does is replace the exponential with sinusoids in
u.   

Does anyone have any ideas on what to do?  I haven't even been able to
visualize the function.    Any suggestions will be greatly appreciated.   

Thanks


Ramesh

Ramesh@mv3600.bmen.tulane.edu
Newsgroups: sci.math.num-analysis
From: ledwards@leland.Stanford.EDU (Laurence James Edwards)
Subject: RE: Polygon in or out?
Organization: DSG, Stanford University, CA 94305, USA
Date: Fri, 11 Sep 92 06:27:55 GMT

In article <1992Sep9.141511.23893@dutrun2.tudelft.nl>, rcpshdb@dutrun2.tudelft.nl (Han de Bruijn) writes:
|> In article <1992Aug25.195204.28914@eng.ufl.edu> Ed Deeters:
|> > Hi, does anyone know a fast way to determine if a point(x,y) is inside
|> > or outside of a polygon when the polygon is defined by n points(x,y) 
|> > given in a clockwise manner?
|> 
|> [.....]
|> 
|> What do you want? In-out algorithms are _either_ fast XOR reliable!
|> 
|> [.....]
|> 
|> Reliable algorithm (NOT cheap):
|> ------------------
|> Instead, determine the _angle_ between ai and bi (: quite expensive!).
|> The sum of all these angles (FOR i=1 to N-1) divided by  2.pi  equals
|> the so called "winding number" for  p . If the winding number is < 0.5
|> then  p  is outside the polygon. The higher the point's winding number,
|> the more it is enclosed by the polygon.

According to conventional wisdom the ray crossing method (see Preparata
and Shamos for the general idea) is faster (I've never checked this myself)
and is also reliable. The details of the special cases can be a little messy
but there is a trick, which I don't remember right now, which makes for clean,
fast, reliable code (if you are desperate, e-mail me and I'll take a look at
the code to refresh my memory). This should be in the FAQ(s) since this is
asked every month or two.

Larry Edwards
edwards@sunrise.stanford.edu
Newsgroups: sci.math.num-analysis
From: rcpshdb@dutrun2.tudelft.nl (Han de Bruijn)
Subject: RE: Pi to 20,000 places
Originator: rcpshdb@dutrun2.tudelft.nl
Reply-To: rcpshdb@dutrun2.tudelft.nl (Han de Bruijn)
Organization: Delft University of Technology
Date: Mon, 14 Sep 1992 07:00:49 GMT

In article <1992Sep13.152323.12127@ramsey.cs.laurentian.ca> Barry G. Adams:
> 
>     |\^/|      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.
> > evalf(Pi,20000);
> Float(
> 
> 31415926535897932384626433832795028841971693993751 [ ... stuff deleted ... ]
> quit
> bytes used=730080, alloc=655240, time=567.850

OK. Can't resist:

    |\^/|      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.
> evalf(1,20000);
Float(

1000000000000000000000000000000000000000000000000000000000000000000000000000000\
0000000000000000000000000000000000000000000000000000000000000000000000000000000\
0000000000000000000000000000000000000000000000000000000000000000000000000000000\
00000000000000000000000 .... Yaaaaaaaawn ....
-- 
* Han de Bruijn; Applications&Graphics | "A little bit of Physics * No
* TUD Computing Centre; P.O. Box 354   | would be NO idleness in  * Oil
* 2600 AJ  Delft; The Netherlands.     | Mathematics" (HdB).      * for
* E-mail: Han.deBruijn@RC.TUDelft.NL --| Fax: +31 15 78 37 87 ----* Blood
Newsgroups: sci.math.num-analysis
From: vsnyder@jato.jpl.nasa.gov (Van Snyder)
Subject: Fortran codes for Fresnel Integrals
Organization: Jet Propulsion Laboratory
Date: Tue, 8 Sep 1992 19:37:44 GMT

I'm looking for Fortran codes for Fresnel integrals.  I've looked
at netlib, in Slatec and in CMlib.  There is a rumor they've
appeared in published literature, but I can't find them.  There
are codes in NAG and CERN libraries, but they're not in the
public domain.  It's a little embarrasing to give a colleague
a code and say "by the way, you need to send $k xxx to so-and-so
every year to continue using this code."

e-mail please, as my access to news is difficult and erratic.
-- 
vsnyder@jato.Jpl.Nasa.Gov   vsnyder@math.Jpl.Nasa.Gov  <-- preferred
ames!elroy!jato!vsnyder     ames!elroy!math!vsnyder
vsnyder@jato.uucp
Newsgroups: sci.math.num-analysis
From: takriti@engin.umich.edu (samer Takriti)
Subject: Pari ??
Date: Mon, 14 Sep 92 17:40:32 EDT
Organization: University of Michigan Engineering, Ann Arbor

Somebody in this new group posted a message about a program called
Pari. It is supposed to do calcualtions with 2 * double precision
(This is what I understood at least). Does this program exist for
the Unix workstations, i.e., sun, ibm/6000, etc. ?
Can anybody give me some more information about it ?
Thanks.
-Samer
Newsgroups: sci.math.num-analysis
From: john@aquarius.unm.edu (John Prentice)
Subject: Re: Interpolating 2D and 3D randomly spaced data
Date: Wed, 09 Sep 92 06:00:16 GMT
Organization: Dept. of Physics & Astro, University of New Mexico, Albuquerque
Distribution: inet

>  I am looking for algorithms for interpolating 2D and 3D randomly
>spaced data, preferably with error estimation.  Any pointer is
>appreciated.
>

Look in the Transactions of Mathematical Software, published by the
Association for Computing Machinery.  In the 1985 on range, there
have been quite a large number of papers written on precisely this 
topic.  These papers include code, which can be obtained ftp from
netlib.  I have used some of the algorithms published in TOMS for
this purpose and they have worked great.

John
-- 
Dr. John K. Prentice                      
Partner, Quetzal Computational Associates    
3200 Carlisle N.E., Albuquerque, NM   87110-1664; 505-889-4543
john@aquarius.unm.edu -or- jkprent@cs.sandia.gov -or- prentice@rufous.cs.unm.edu
Xref: sparky sci.math.num-analysis:2678 sci.math.symbolic:2374
From: popineau@pelletier.loria.fr (Popineau Fabrice)
Newsgroups: sci.math.num-analysis,sci.math.symbolic
Subject: Solving a non-linear partial differential equation
Date: 10 Sep 92 15:27:34 GMT
Followup-To: sci.math.num-analysis
Distribution: sci
Organization: CRIN, Nancy, France


Dear netters,

Do you kown if there exists a software package (Public Domain or not)
that has builtin function for solving numerically this type of
differential equation ? More specifically, it is a second order
partial differential equation (non-linear Schrodinger equation).

Any pointers would be appreciated,

Thanks,

F. Popineau
--
e-mail       : popineau@loria.loria.fr, popineau@ese-metz.fr
phone-mail   : (+33) 87 74 99 38 ext: 320
surface-mail : Ecole Superieure d'Electricite
	       2 rue E. Belin
	       F-57078 METZ Cedex 3
	       FRANCE
From: harper@kauri.vuw.ac.nz (John Harper)
Newsgroups: sci.math.num-analysis
Subject: Heun and Runge-Kutta
Date: 15 Sep 92 22:17:12 GMT
Organization: Victoria University of Wellington

Some textbooks (e g Burden & Faires "Numerical Analysis") call a second-
order Runge-Kutta method for ordinary differential equations Heun's method. 
Did Heun publish first and not discover the higher-order R-K methods, or 
is there some other reason for his name to be on it?

John Harper Mathematics Dept. Victoria University Wellington New Zealand
From: tayloe@uinpla.npl.uiuc.edu (Rex Tayloe)
Newsgroups: sci.math.num-analysis,sci.math.stat,sci.physics
Subject: Re: HELP: A least-squares problem with nonlinear constraints
Date: 10 Sep 92 02:18:33 GMT
Reply-To: tayloe@uinpla.npl.uiuc.edu (Rex Tayloe)
Organization: Nuclear Physics Laboratory, University of Illinois, Urbana-Champaign

In article <0096060C.3C725B20@uinpla.npl.uiuc.edu>, I wrote
>
>   I have been struggling with a problem that I have encountered in my thesis
>analysis and would like to pose the problem to see if there might be a kind
>soul out there with some helpful advice.
>
>   I am analyzing data from an experiment where we collide antiprotons with
>protons and look at several hyperon channels. My particular goal is to find
>the antiproton,proton->lambda,sigma (pbar,p->LS) events.  And, because they 
>are very similar, I am also looking at antiproton,proton->lambda,lambdabar
>(pbar,p->LL) events.
>
>   So, for each event I want to do a least-squares fit subject to
>energy-momentum conservation at each vertex (3*4 equations for LL, 4*4 for LS).
>The least-squares sum I want to minimize is: 
>                        (ymeas-yfit)V(ymeas-yfit)
>             transpose---^^^^^^^^^^
I meant:
                        (ymeas-yfit)V(-1)(ymeas-yfit)
             transpose---^^^^^^^^^^


   __    __    ____     __
 /__/\ /__/| /____/ \ /__/|     Rex Tayloe           TAYLOE@uinpla.npl.uiuc.edu
 |   \\| | ||  __ \ /|| | |     Nuclear Physics Lab  TAYLOE@uiucnpl.bitnet 
 | |\ \| | || |__) |/ | | |__   U of Illinois        UINPLA::(47165::)TAYLOE
 | | \   | ||  ___/   | |/__ /| Champaign Il 61820   (317)333-3190
 |_|/ \ _|/ |_|/      |_____|/