HDTenEightyP/NetNews huggingface dataset:
From: mjackson@magnus.acs.ohio-state.edu (Michel T Jackson)
Subject: fitting circle to data points on small arc
Followup-To: sci.math.num-analysis
Organization: The Ohio State University
Distribution: na
Date: Thu, 9 Apr 1992 00:36:31 GMT

Dear whomever,

I have a problem that has turned out to be harder than expected.  The problem
is estimating the parameters of the best-fit circle given a set of
modestly noisy points along a short arc.

The situation arises in attempting to numerically estimate the radius and
position of the center of rotation of the lower jaw while it is moved up &
down in the  "terminal hinge postion" (try clenching your teeth while pulling
your jaw all the way back.  If you then wiggle your jaw up & down a few
millimeters, you  will have executed a close-to-pure rotational motion.  Any
more than a few mm results in the translation of the mandible as well).  We can
fit a rigid splint to the lower teeth, and track its position while it
executes this small rotation.  Typically, the radius (i.e., distance from the
"hinge point" to the lower teeth, or tip of the splint) is on the order of
10-15 mm; the angle subtended by the arc is on the order of 10-15
degrees.

It is possible to solve this problem easily if the data are
noise-free (I've fooled around with simulated data in Matlab, using SVD
methods, & gotten back answers correct to 8 places). I do this by
setting up the following system:

[x y 1]  [a b c]' = -[ (x.*x) + (y.*y) ]

(x, y column vectors; .* is the "elementwise product" operator in
Matlab) and solving for a, b, & c.

However, even small amounts of noise (i.e., adding 0.2*rand(xydata) to
xydata, when xydata was generated using a radius of 10 mm over a 10 or
15 degree arc) produces large errors in the answers.  Evidently, this
is a poorly conditioned system (again, fooling around with Matlab has
revealed condition numbers on the order of 10,000).  It is poorly
conditioned (I think) because the small angle covered during the
rotation, together with the relatively large radius, results in little
variation in e.g. xs relative to ys (for jaw positions near horizontal).

I've found one reference to a paper on solving this problem (or
something closely related) - except that it was a Bell Labs internal
manuscript of some sort, & I haven't had any luck locating it.  I
would have thought that there was some way of exploiting the specific
properties of this data, but i haven't thought of it.

Any suggestions that you have will be welcome.  email me
at either of the addresses below if you want to keep net bandwidth down.

jackson@shs.ohio-state.edu
mjackson@magnus.acs.ohio-state.edu

Thank you,

     Michel Jackson
Newsgroups: sci.math.num-analysis
From: hatay@spot.Colorado.EDU (Ferhat F. Hatay)
Subject: Re: Eigenvalue,Eigenvector (part II)
Organization: University of Colorado, Boulder
Date: Tue, 14 Apr 1992 14:42:01 GMT


I am having difficulties to reach Eurepan dudes (dudesses!) by mail, 
somewhat they keep rejecting my mail. So, please forgive my overuse
of network to communicate the following -deep thoughts- to them. 
I don't claim any liability for my suggestions, anyone is welcomed 
to find any holes in my reasoning. feel free to poke my failing eyes. 
 
In article <17229@sophia.inria.fr> falzon@sophia.inria.fr writes:
>
> Does anybody have the general forms of eigenvalues and eigenvectors of an NxN
> pseudo-tridiagonal matrix of the form :
> 
> For example with N=4;
> 
>
>	[(1+1/a) -1/a       0         0 ]
>  A = 	[-1/a    (1+2/a)  -1/a        0 ]
>	[ 0       -1/a    (1+2/a)  -1/a ]
>	[ 0         0      -1/a  (1+1/a)] 
>
> Thanks in advance.
>
>
>      Fred.
>-----------------------------------------------------------------------------------------

Hmm, The problem adds to its lure when we consider it with 
some boundary conditions. It stops being circulant and
turns to a headache. Assuming that this is a solution
to a second order pde like Helmholtz or Poisson, let me 
suggest the following:

For dirichlet boundary conditions we can fold them 
onto (or into?) a system of order of N-2. The 
resulting -nonsingular- system (matrix) will again
have a circulant structure and a different right 
hand side. 

For neumann boundary conditions: I use my eigenvalue solver!

I still think there is an analytical solution for the problem
mentioned here. If we solve the eigenproblem for a matrix A:

    A = Q D Qt where D is diagonal matrix of eigenvalues.

    Q A Qt = D 

what would be the solution for

    B = A + S ? where S is a diagonal matrix. 

let's try:

   Q B Qt = Q A Qt + Q S Qt
    
   Q B Qt =  D + Q S Qt 

then what? eigenvectors of matrix B are Q same as the original 
matrix A and eigenvalues are given by D + S?

Do you see any holes in the reasoning above? It was rather
spontaneous so I should have probably checked myself.
  
cheers, 

Ferhat


-- 
Ferhat F. Hatay                        || Disclamer: |||||||||||||||||
Aerospace Engineering Sciences         || I speak for myself unless || 
University of Colorado, Boulder        || otherwise indicated.      ||
e-mail: hatay@spot.colorado.edu        |||||||||||||||||||||||||||||||
Newsgroups: sci.math.num-analysis
From: shihtsun@ec.ecn.purdue.edu (Shih-tsun Alex Chou)
Subject: overview of numerical analysis
Organization: Purdue University Engineering Computer Network
Distribution: na
Date: Thu, 16 Apr 1992 13:15:16 GMT

	I hope this is not an old question. Could anyone suggest me 
a book or a paper which gives overviews/introductions of many (every?) 
areas of numerical analysis, preferred with some introductions to 
modern trends but without very-detailed math? Does there exist such 
a book/paper?

Thanks in advance!!

Alex
From: cohen@alioth.greco-prog.fr (Henri Cohen)
Newsgroups: sci.math.num-analysis
Subject: radial spheroidal wave functions
Date: 7 Apr 92 10:31:59 GMT
Reply-To: cohen@alioth.greco-prog.fr (Henri Cohen)

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

--------------------------------------------------------------
From: stan@sabaac.mayo.edu (Andrew Staniszewski)
Newsgroups: sci.math.num-analysis
Subject: math routines wanted
Date: 16 Apr 92 20:33:33 GMT
Article-I.D.: bmw.1992Apr16.203333.23621
Organization: Mayo Foundation

I am looking for some special function routines for kelvin functions,
if someone has public domain functions (any language) for ker and kei
please send me mail

I am also looking for c++ integration and matrix LU factorization and Linear
System solution routines


If you know where I could get these routines please email me at 


stan@sabaac.mayo.edu
From: nicot@cwi.nl (Nico Temme)
Newsgroups: sci.math.num-analysis
Subject: Complex complementary error function
Date: 7 Apr 92 08:23:38 GMT
Organization: CWI, Amsterdam

> Hugh Songh writes:
> Has anybody tried to program this special function?  
> Can I convert the declaration statement of "fullerton's library"
> derfc appropriately to obtain the complex version?  BTW,
> fullerton's derfc seems to utilize Tchebyshev rational
> approximation.

Answer: no; you should never translate Tchebyshev rational
approximation for real intervals to the complex case.

>The other option is to implement Formula 7.1.29 of 
> Abramowitz/Stegun for complex erf, which is an 
> infinite series of a complex elementary functions.

Answer: formula 7.1.29 of Abramowitz/Stegun is quite 
acceptable. However, Algorithm 680 of TOMS (available through
netlib) is more efficient. It computes a 14d approximation 
of the function w(z) for complex values of z. See formula 7.1.3
 of Abramowitz/Stegun. A description of the algorithm is given in
TOMS, Vol. 16, pp.38-46, 1990.

-- 
Nico M. Temme                                   : nicot@cwi.nl
CWI (Centre for Mathematics & Computer Science) : tel +31 20 592 8020 x 35
Kruislaan 413, 1098 SJ Amsterdam, Netherlands.  : fax +31 20 592 4199
P.O. Box 4079, 1009 AB Amsterdam, Netherlands.
From: dmatthews@uap.umd.edu
Newsgroups: sci.math.num-analysis
Subject: Re: WANTED: digital filter source code
Date: 8 Apr 92 20:26:09 GMT
Reply-To: dmatthews@uap.umd.edu
Organization: IPST, U. of Maryland, College Park

In article <73276@netnews.upenn.edu>, jim@heart.circ.upenn.edu (Jim Streicher) writes:
>
>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. 
>
...
If this is not a real-time problem, the easiest way and the one that gives you
the most control is to filter in the frequency domain.  There you can create
your filter to have the exact characteristics you want, multiply it by the
data, and transform the result back to the time domain.  It is a good idea to
look at the impulse response of your filter (the absolute value of its
transform) to see that it does not produce spurious ringing in the filtered
data or otherwise unacceptably distort sudden changes. This method is treated
inadequately or not at all in the few texts I have looked at.  I don't have any
actual code you could use, sorry. 

Dr. David L. Matthews, IPST, Univ. of Maryland, College Park MD 20742-2431 
Telephone  (301)405-4830	Internet   dmatthews@uap.umd.edu
FAX 	   (301)314-9363	NSI/SPAN   UMDUAP::DMATTHEWS
Newsgroups: sci.math.num-analysis
From: tpaquette@ita.lgc.com (Trevor Paquette)
Subject: Lottery Numbers
Organization: Landmark/ITA Inverse Theory and Applications
Distribution: sci
Date: Tue, 14 Apr 1992 16:38:40 GMT


 This may have been discussed to death here already, but I only just
re-subscribed to this group, so apologies in advance.

 I just saw an ad on TV for the 'Marion Petrick' (sp?) Lottery picker.

 All this this does is given a list of 14 numbers, it arranges them in
 groups of 6 for 12/15/20/40(etc.. ) tickets to maximize your chances
 at winning. So if at leat 3 of your 14 numbers are drawn you should
 have at least 9 winning tickets. You should get the idea.
 
   Question: Does anyone have source to do this or a description of
 how to do this? I am not a numerical analysis whiz (I'm a computer
 geek :-)) so lots of theory is not going to help me..

    Trev
--
Trevor Paquette                   | Landmark/ITA, Inverse Theory & Applications
tpaquette@ita.lgc.com             | Suite 1101, 425 1st St S.W.
Visitor from CyberSpace           | Calgary, Alberta, Canada   T2P 3L8
Renagade from Virtual Reality     | Phone:(403) 269-4669        'Fahrvergnugen'
From: henrikj@nexus.se (Henrik Johansson)
Newsgroups: sci.math.num-analysis
Subject: Searching for bignum package on IBM PC
Date: 7 Apr 92 10:34:59 GMT
Organization: NEXUS Communications AB, Uppsala, Sweden


Anybody knows where I can find a bignum package that'll compile and
run in an 8086-environment?  I've written a package myself, but it
seems to be a little slow...:-)

It doesn't matter if it's written in assembler or C (preferably C, of
course), just as long as it has addition, subtraction, multiplication,
division and comparison routines.  And is fast.  And PD or shareware.

/hj
----
--
Real life:   Henrik Johansson            Email:  Henrik.Johansson@Nexus.Comm.SE
Snailmail:   Communicator Nexus          Phone:  +46 18 171811
             Box 857                     Fax:    +46 18 696516
             S - 751 08 Uppsala, Sweden
Newsgroups: sci.math.num-analysis
From: zika@gn.ecn.purdue.edu (Michael Zika)
Newsgroups: sci.math.num-analysis
Subject: Finding Eigenvalues of a Large Matrix
Keywords: EISPACK, IMSL
Date: 9 Apr 92 21:57:47 GMT
Article-I.D.: gn.1992Apr9.215747.28284
Organization: Purdue University Engineering Computer Network


  I am attempting to find the spectral radius of a larger
matrix (241x241).  It's ~98.5% sparse, not banded and asymmetric.

  Since I'm only after the largest eigenvalues,
my first attempt was a power method.  However, this was divergent
in some cases (in retrospect, I realize that there is no
guarantee that the eigenvalue is real of that it doesn't appear as
both the negative and positive values).

  I then implemented IMSL (routine: DEVLRG), which would not
run to completion because of a large predicted performance index.

  Trying EISPACK (subroutine: RG) gave results that looked reasonable,
but when I transpose the matrix and calculate the eigenvalues of the
transposed matrix (with EISPACK) I get different results than the
untransposed matrix...

  The questions are:
    1) Which method is most "believable"?
    2) As there any recommendations on another algorithm that could
       be attempted?

  Any help/suggestions would be appreciated.

  Thanx in advance.


-- 
                                     |
Michael Zika (zika@ecn.purdue.edu)   |    Hey don't ask me "why?",
Purdue University                    |    I'm still working on "how?" ! 
School of Nuclear Engineering        |
From: mth015@muvms3.bitnet
Newsgroups: sci.math.num-analysis
Subject: Where to get softwears LINDO and GINO ?
Date: 11 Apr 92 10:40:13 GMT
Organization: Marshall University

Dear fellows: I need your help to find out where I can get softwears
LINDO (linear interactive and discrete optimizer) and GINO (general
interactive nonlinear optimizer) for solving linear/nonlinear programing
problems ?
Newsgroups: sci.math.num-analysis,sci.math.stat,sci.math
From: roy@zooks.eng.mcmaster.ca (Roy Underhill)
Subject: Moment generating function for Multinomial Distribution
Summary: wanted
Keywords: moment generating function, multinomial distribution
Organization: Mech. Eng., McMaster Univ., Hamilton, ON, Canada
Date: Thu, 16 Apr 1992 17:25:17 GMT

All Helpful Netters,

	I have a request from a colleague.  I could not answer it; so
I am asking the world at large.  Does anyone know the moment
generating function for a multinomial distribution?  If so, please
either post of e-mail to me.  My colleague will be very grateful.
Thanks to all,

Roy Underhill

   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~  
  Roy Underhill,  (416) 525-9140 x4395   roy@zooks.eng.mcmaster.ca 
  Department of Mechanical Engineering,  McMaster University, 
  Hamilton,  Ontario,  Canada            L8S 4L7
Newsgroups: sci.math.num-analysis,comp.lang.c
From: dow@nova2.stanford.edu (Keith Dow)
Subject: Re: Digital-age counterpart for Abramowitz/Stegun?
Organization: Stanford University
Date: Tue, 7 Apr 1992 04:10:46 GMT


Baker  "C Mathematical Function Handbook"  is A&S with disk and code
documentation.  Enjoy.
From: ramesh@MV3600.BMEN.TULANE.EDU
Newsgroups: sci.math.num-analysis
Subject: integral equations
Date: 14 Apr 92 00:25:08 GMT
Article-I.D.: MV3600.009590E8.563C69E0
Reply-To: ramesh@MV3600.BMEN.TULANE.EDU
Organization: TULANE, BMEN, NEW ORLEANS, LA
Nntp-Posting-Host-[nntpd-13983]: mv3600.bmen.tulane.edu


	I was wondering if anyone knows where to look for programs to solve 
integral equations.  What I really need is some info on theory since I want to
solve a coupled set of integral equations both nonlinear and linear.  Any
suggestions will be of great help.     


					Thanks 

					ramesh srinivasan
					ramesh@mv3600.bmen.tulane.edu
From: kramer@hera.ics.uci.edu (David Kramer)
Subject: Conferences
Newsgroups: sci.math.num-analysis
Reply-To: kramer@ics.uci.edu (David Kramer)
Organization: UC Irvine Department of ICS
Date: 7 Apr 92 22:46:50 GMT


I am relatively new to the field of numerical analysis. What are the
significant conferences and journals in the field. If there is sufficient
interest I will summarize to the net.

David


David Kramer                        |
Dept of ICS                         |
Univ of California                  |      Why do we chop trees down
Irvine, CA 92717                    |      and then chop them up?
                                    |
Internet: kramer@paris.uci.edu      |


Newsgroups: sci.math.num-analysis,sci.math.symbolic
From: ukrainec@nimios.eng.mcmaster.ca (Andrew Ukrainec)
Subject: Re: Matlab primer needed.
Organization: Communications Research Laboratory, McMaster Univ
Distribution: na
Date: Thu, 16 Apr 1992 01:27:21 GMT

In article <sdd7cINN9hf@agate.berkeley.edu> pous@diva.Berkeley.EDU (Rafael Pous) writes:
>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)

There is a MATLAB primer written in LaTeX (or PostScript) available
on the NETLIB server.  Its free, and gives a nice introduction and
table summary of basic functions.
-- 
         Andrew Ukrainec                 ukrainec@nimios.eng.mcmaster.ca 
          <    (*) >               /  \             < (*)    >           
Communications Research Laboratory      McMaster Univ, Hamilton, Ontario
From: jeff@mozart.helios.nd.edu (Jeff Kantor)
Newsgroups: sci.math.num-analysis
Subject: Matlab toolbox for wavelets
Date: 8 Apr 92 15:09:19 GMT
Article-I.D.: news.1992Apr8.150919.24218
Organization: University of Notre Dame, Notre Dame

So far I have received 75 requests in response to my offer last
week of a small set of matlab functions for playing with orthogonal
wavelets. I wasn't expecting this, and so I am sort of overwhelmed.
In any event, I set up a little shell script to do the mailing for
me, and, if everything worked, than everyone who requested a copy
should by now have received a uuencoded and tarred file containing
matlab functions, TeX documentation, and a bibliography.

I am continuing to develop this toolbox for my own use. Any comments
you have would be appreciated. I'll send out an updated version of
these items as it seems appropriate.

Jeff Kantor
Notre Dame
From: drumhell@n5160a.nrl.navy.mil (David Drumheller)
Newsgroups: sci.math.num-analysis
Subject: Continued fractions and special functions.
Keywords: continued fractions, special functions
Date: 6 Apr 92 12:56:11 GMT


    During the course of my research in the application of order
statistics to detection theory, I found it necessary to compute
the incomplete gamma function.  I used a routine from Numerical
Recipes in C (by Press et al) which is based on a continued fraction
expansion.  None the of references in the book contain a derivation
of this expansion.
    
    Question: does anybody know of a reference that gives a
explanation/derivation of the continued fraction expansion of the
incomplete gamma function or any other special functions?

    More generally, does anybody know of a good reference on
continued fractions?

    Please e-mail responses to me directly.  Thank you!
    
Dave Drumheller
Naval Research Laboratory
Acoustics Division, Code 5160
Washington, D.C.  20375
USA
(202) 767-3524
e-mail address: drumhell@n5160a.nrl.navy.mil
Newsgroups: sci.math.num-analysis
From: jdg41088@uxa.cso.uiuc.edu (Pickaxe)
Subject: REQUEST: Algorithm for PI
Keywords: PI
Organization: University of Illinois at Urbana
Date: Wed, 8 Apr 1992 20:30:16 GMT

I'm looking for any Algorithm that will calculate specific decimals of PI.
I heard that there is at least one out there that will give any number chosen.

Please reply to me.

Thanks.
-- 
Joe Gross
University of Illinios at Urbana-Champaign
Department of Electrical and Computer Engineering
pickaxe@uiuc.edu
From: mbgapdk@uts.mcc.ac.uk (Dr. D. Kidger)
Newsgroups: sci.math.num-analysis
Subject: Numerical integration of squares,cubes etc.
Date: 9 Apr 92 11:53:36 GMT
Organization: Manchester Computing Centre, Oxford Road, Manchester, M13 9PL, England.

Does anyone have any references to integration formulae for 2d/3d 'squares' 
other than the 'standard' product Gauss rules.
 I have 6,14 and 15 point rules for cubes (range -1--> +1) and a 
'better than 3x3x3 Gauss' 27 point rule for cubes.

In particular what are the optimal sampling points (and weights) for 9
integration points in 2d ?

--------- Dr. Dan Kidger ------ Dept. of Civ Eng. Manchester, UK ---------
Xref: sparky sci.math.num-analysis:1395 sci.math.symbolic:1197 sci.math.stat:981 sci.research:464
From: laws@ai.sri.com (Kenneth I. Laws)
Newsgroups: sci.math.num-analysis,sci.math.symbolic,sci.math.stat,sci.research
Subject: Re: Announcement New Journal: Scientific Programming, Call for Papers
Date: 5 Apr 92 19:05:10 GMT
	<WVENABLE.92Apr5222551@spam.maths.adelaide.edu.au>
Followup-To: sci.math.num-analysis
Organization: Computists International
In-reply-to: wvenable@spam.maths.adelaide.edu.au's message of 5 Apr 92 12:55:51 GMT

> From Bill Venable:
> We must surely be getting close to the time when new journals -and
> especially this one- could appear in a purely electronic edition as well as
> the old, profligate, paper style.  Just how difficult would it be to offer
> a journal in some electronic to readers, by email, at least as a quick,
> cheap alternative to paper?

Bill --

You are right, it can be done.  And is being done.  Steven Harnad has
been publishing BBS and PSYCHOLOQUY for some time, and is active in
the community of librarians (and such) that is trying to make
e-journals common.  There's also a medical journal that is going
to publish in online form, complete with graphics.  Newsletters
have been available for some time, including my own for AI researchers
and several hundred for the business community.  (Mine is on the net,
with permission from NSF to use the backbone.  Most of the others are
available through commercial providers like CompuServe.)

I'm a believer in using whatever resources are currently available.
Most of the publishing industry, however, is waiting until there's
a significant market with multimedia-capable computers hooked into
the commercial networks.  The medical journal I mentioned is providing
the front-end software for viewing its graphics, and paying for the
development of that software greatly increases the start-up cost.

					-- Ken
--

Dr. Kenneth I. Laws, (415) 493-7390, laws@ai.sri.com.
Moderator of the Computists International AI/IS/CS mutual-aid association.
Ask about my weekly online career newsletter, The Computists' Communique.
From: ftkgr@acad3.alaska.edu (RICHARDS KENNETH G)
Newsgroups: sci.math.num-analysis
Subject: Re: absorbing boundary conditions for PDE's?
Date: 16 Apr 92 19:32:28 GMT
Reply-To: ftkgr@acad3.alaska.edu
Organization: University of Alaska - Fairbanks
News-Software: VAX/VMS VNEWS 1.4-a3

In article <renns.703315913@sfu.ca>, renns@fraser.sfu.ca (R Enns) writes...
> 
>Does anyone have any experience with absorbing boundary conditions for PDE's?

There was a comprehensive review by Dan Givoli in:
Journal of Computational Physics v94 p 1-29 (1991)

I'm still trying to figure out how to apply some of this to my work (hybrid 
plasma simulations) so I don't have much experience yet.

Ken Richards
ftkgr@acad3.alaska.edu