HDTenEightyP/NetNews huggingface dataset:
From: gchoksi@at4cad.intel.com (Gaurang Choksi)
Newsgroups: sci.math.num-analysis
Subject: Program for polynomial curve fit (regression) for a set of data
Date: 16 Oct 92 19:08:58 GMT
Organization: intel
Originator: gchoksi@at4cad

Is there a statistical library available on the net, similar to 
linpack ? I need to fit a set of data to an Nth order polynomial.
A C program is preferable. 

Thanks,


----------------------------------------------------------------------------
Gaurang Choksi, Ph.D.,  New Package Technology Development 
Intel Corporation, CH5-137, 5000, W.Chandler Blvd. Chandler, AZ 85226.
gchoksi@at4cad.intel.com, Phone (602)-554-2335, Fax (602)-554-7615
----------------------------------------------------------------------------




-- 
----------------------------------------------------------------------------
Gaurang Choksi, Ph.D.,  New Package Technology Development 
Intel Corporation, CH5-137, 5000, W.Chandler Blvd. Chandler, AZ 85226.
gchoksi@at4cad.intel.com, Phone (602)-554-2335, Fax (602)-554-7615
From: ss4i@kelvin.seas.Virginia.EDU (Sriram  Srinivasan)
Subject: Scaling in Optimization
Originator: ss4i@kelvin.seas.Virginia.EDU
Organization: University of Virginia
Date: Thu, 8 Oct 1992 19:54:49 GMT

Hi,

  a question about "scaling" of variables in optimization problems. A
commonly used approach is the linear trasformation:

             x = D*y + c; {x} - original vars., {y} - transformed vars.

suppose an element x_j lies in [a_j,b_j]. Then we have

         D(j,j) = 0.5*(b_j - a_j) and c(j) = 0.5*(b_j + a_j)
      
This ensures that  -1 <= y_j <= +1 .

  In my particular application, I have a range such as [1,1e5]. If I
use the above procedure, it turns out that values in the range [1,1e4]
(approximately) are "compressed" into [-1,-0.8]. This would be a
problem if say the gradients are computed by finite differences.

Another scaling method would be y = log10(x). This avoids the
"compression" problem but gradient computations would be screwed up
(if you use a canned code like I am).

Does anybody have experiences with scaling problems like this?
Any suggestions and pointers would be much appreciated. Thanks.

-sriram (a novice in the practicalities of optimization)

-------------------------------------------------------------------------------
Sriram Srinivasan                        ss4i@kelvin.seas.virginia.edu
Dept. of Mech. and Aero. Engg
Univ. of Virginia
-------------------------------------------------------------------------------
From: bardo@ief-paris-sud.fr (Bardo Muller)
Newsgroups: sci.math.num-analysis
Subject: EMLIB site
Keywords: microwave, numerical methods
Date: 12 Oct 92 13:17:04 GMT
Reply-To: bardo@ief-paris-sud.fr
Organization: Universite de Paris

Dear readers,

A couple of months ago EMLIB, a ftp-able site for microwave-specific
codes at

microwave.jpl.nasa.gov (IP address 128.149.76.31)

was announced. Below is t text I received. The site times out since.

Any information on status/alternative access to EMLIB would be
greatly acknowledged.

============================================================================
 Bardo MULLER                          | phone  : [33] [1] 69 41 78 50    
 Institut d'Electronique Fondamentale  | fax    : [33] [1] 60 19 25 93    
 Bat. 220 Universite Paris Sud         | e-mail : bardo@ief-paris-sud.fr  
 91405 ORSAY CEDEX FRANCE              |             THE NET WORKS !      
============================================================================



						10 July 1992

TO:      Electromagnetics workers everywhere
FROM:    EMLIB staff (T. Cwik, JPL, S. Ray, LLNL)
SUBJECT: EMLIB: An Internet Server for Electromagnetic Software



EXECUTIVE SUMMARY
-----------------

EMLIB, an Internet server for the free distribution of electromagnetic
(EM) software and related information, has been established at JPL. 
This server, microwave.jpl.nasa.gov (IP address 128.149.76.31), is now
accessible via anonymous ftp.  The EMLIB staff is actively seeking
additional material to put on the server; we encourage any one with
appropriate codes, data, etc. to put their material on EMLIB so that it
can be shared (and perhaps even improved) by the greater community of
EM workers.

.....
Newsgroups: sci.math.num-analysis
From: khattra@cs.sfu.ca (Taj Khattra)
Subject: Re: adaptive function plotting?
Organization: CSS, Simon Fraser University, Burnaby, B.C., Canada
Distribution: usa
Date: Wed, 7 Oct 1992 23:06:58 GMT

In article <1926@hsdndev.UUCP> stvjc@gauss.med.harvard.edu (Vincent Carey 2-3265) writes:
>would appreciate references or pointers on software for
>function plotting in which grid points are chosen more
>finely as the function becomes rougher.

There was a paper by Richard Fateman (of UC Berkeley) titled 
"Honest Plotting, Global Extrema, and Interval Arithmetic".

I ftp'ed it from <I-dont-remember-where> and I don't have
a copy online anymore. Here's the abstract

____
        A computer program to honestly plot curves y = f(x) must
     locate maxima and minima in the domain of the graph. To
     do so it may have to solve a classic problem in computation -
     global optimization. Reducing an easy problem to a hard one
     is usually not an advantage, but in fact there is a route to
     solving both problems if the function can be evaluated using
     interval arithmetic. Since some computer algebra systems
     supply a version of interval arithmetic, it seems we have the
     ingredients for a solution.
        In this paper we address a particular problem how to compute
     display "honest" graphs of 2-D mathematical curves. By "honest"
     we mean that no significant features (such as the location of
     poles, the values at maxima or minima, or the behaviour of a
     curve at asymptotes) are misrepresented. By "mathematical" we mean
     curves like those generally needed in scientific disciplines
     where functions are represented by composition of common
     mathematical operations: rational operations (+, -, *, /),
     exponential and log, trigonometric functions as well as
     continuous and differentiable functions from applied mathematics.
____

I also don't know where it was published. You may be able to contact
the author at "fateman@math.berkeley.edu".

--
Taj Khattra
From: bardo@ief-paris-sud.fr (Bardo Muller)
Newsgroups: sci.math.num-analysis
Subject: Re: [sci.math.num-analysis] EMLIB site
Keywords: electromagnetics
Date: 15 Oct 92 08:52:58 GMT
Reply-To: bardo@ief-paris-sud.fr
Organization: Universite de Paris
Cc: alan@elroy.jpl.nasa.gov, cwik@hyper-sun2.jpl.nasa.gov, ray4@llnl.gov, jinlee@ee.wpi.edu
	
	
	In article <1bh214INNs40@agate.berkeley.edu> bardo@ief-paris-sud.fr writes:
	>A couple of months ago EMLIB, a ftp-able site for microwave-specific
	>codes at
	>
	>microwave.jpl.nasa.gov (IP address 128.149.76.31)
	>
	>was announced. Below is t text I received. The site times out since.
	>
	>Any information on status/alternative access to EMLIB would be
	>greatly acknowledged.
	
	Everyone should know that recent changes in Laboratory policy forbid free
	distribution of software written at JPL unless distribution is to NASA or to
	someone under contract.  New lab policy is that if you want something written
	here, you're going to pay for it.  If anyone wants further details call me
	(818-354-0003) or the JPL Technology Utilization Office (818-354-2241).
	-- 
	 
	-- Alan                        # Mountain Dew and doughnuts...
	   ..!ames!elroy!alan          # because breakfast is the most important meal
	   alan@elroy.jpl.nasa.gov     # of the day.

This is no good news indeed. I understand this policy for codes developed
at JPL. What about other material ? The final question is, if anyone
is willing to provide:

	- an anonymous ftp server site
	- maintainers

or to cite the EMLIB starters: 

"
These observations have motivated us to set up a publicly-accessible
library of EM software and related material.  This library, called
EMLIB, is physically located at NASA's Jet Propulsion Laboratory, on
the Internet node microwave.jpl.nasa.gov (IP address 128.149.76.31) and
can be receached via anonymous ftp.

EMLIB is being maintained by a handful of volunteers who actively
solicit and catalogue software.   The software is voluntarily
contributed by workers in the field and is intended for public
distribution. Contributed software should be written in standard
languages, be documented and, if appropriate, contain sample input and
output data.

At present, EMLIB (being quite new) contains only a handful of codes.
By means of this mailing we hope to acquaint EM workers with the concept
of EMLIB, to encourage them to use it, and (especially) to contribute
codes to this effort.
"

Rien a` cirer. 

Bardo

============================================================================
 Bardo MULLER                          | phone  : [33] [1] 69 41 78 50    
 Institut d'Electronique Fondamentale  | fax    : [33] [1] 60 19 25 93    
 Bat. 220 Universite Paris Sud         | e-mail : bardo@ief-paris-sud.fr  
 91405 ORSAY CEDEX FRANCE              |             THE NET WORKS !      
============================================================================
From: luk@ohstpy.mps.ohio-state.edu
Newsgroups: sci.math.num-analysis
Subject: PLTMG
Date: 14 Oct 92 00:30:07 EDT

Can anyone tell me whether PLTMG is capable of solving the elliptic 
partial differential equation with COMPLEX coefficients.
From: ruckman@oasys.dt.navy.mil (Christopher Ruckman)
Newsgroups: sci.math.num-analysis
Subject: Need ref:  least-squares for complex variables
Date: 9 Oct 92 12:23:51 GMT
Reply-To: ruckman@oasys.dt.navy.mil (Christopher Ruckman)
Organization: Carderock Division, NSWC, Bethesda, MD

Can anyone point me to a reference that discusses least-squares solutions
for curve-fitting *complex* variables?

I already know how to do it, but I don't want to derive it in the journal
article I'm writing.  None of the books on my shelf discuss complex
variables.

thanx    8-}
From: chung-hu@cae.wisc.edu (Chung-hung Pan)
Newsgroups: sci.math.num-analysis
Subject: Wanted: Implementation of an A-stable implicit Runge-Kutta method or any other similar methods written in C works in PC or SUN
Date: 16 Oct 92 16:07:53 GMT
Article-I.D.: doug.1992Oct16.110753.13965
Distribution: usa
Organization: U of Wisconsin-Madison College of Engineering

Subject line says it all.   I am looking for the code for ANY other implicit
methods which might be used to solve various stiff ODEs, besides the usual
BDF methods.  Thanks for your attention and help.

Chung
chung-hu@cae.wisc.edu
From: hrubin@mentor.cc.purdue.edu (Herman Rubin)
Newsgroups: sci.math.num-analysis
Subject: Re: numerical integration in several dimensions
Date: 8 Oct 92 01:08:22 GMT
Organization: Purdue University Statistics Department

In article <1992Oct7.144450.5760@wam.umd.edu> dabell@quark.umd.edu writes:
>I am interested in extensions of Gaussian quadrature to several 
>dimensions (sometimes called "cubature").  Can anyone tell me 
>the current state-of-the-art and/or refer me to appropriate 
>literature?  E-mail appreciated.  Thanks in advance.  

There are results of this type, but not particularly new, and the
real problem is that unless LOTS of function evaluations are done,
they do not get into the asymptotics.  

It is not necessarily the case that even in one dimension, Gaussian
quadrature is that great.  If one uses 32-point quadrature, the result
is exact for polynomials of degree 63, but it is not too hard to find
"natural" functions which are not well approximated by polynomials of
degrees under the thousands, at least.
-- 
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
Phone: (317)494-6054
hrubin@snap.stat.purdue.edu (Internet, bitnet)  
{purdue,pur-ee}!snap.stat!hrubin(UUCP)
From: joshi@m.cs.uiuc.edu (Anil Joshi)
Newsgroups: sci.math.num-analysis
Subject: Re: Software for the Assignment Problem
Keywords: software, assignment, scheduling
Date: 14 Oct 92 23:29:27 GMT
Article-I.D.: m.1992Oct14.232927.24873
Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL

takriti@engin.umich.edu (samer Takriti) writes:

>In article <1992Oct14.043850.4095@pslu1.psl.wisc.edu> emmel@pslu1.psl.wisc.edu (Grant Emmel) writes:
>>I'm looking for available software (public domain or not) for a
>>non-commercial/non-educational application (I'm helping a friend)
>>that will solve the assignment problem.  That is the general idea.
>>
>>Any help, from theory to software would be helpful.  Post if it is
>>interesting enough, email in any case.
>>Grant Emmel

>The code should not be hard to write.
>-Samer

Why bother? Try getting the code from netlib@ornl.com (I think the address is
right). There are also a couple of public domain ones, 

one is called netflo written by Kennington and Helagason at Southern Methodist
Univ and the other is called Relax III written by Bertsekas. I have implemented
an Interior point path following version (algo by PM Vaidya) which is better
than netflo and relax III only for very large problem sizes (# edges=>128,000)
but hogs a lot more memory than the other two I mentioned.
If I am right, Grant's problem seems to be about a few hundred edges and a PC
would suffice to solve the problem. Get netflo (it is FORTRAN). It is very fast
for small problems.

Anil


-- 
Sathsangatve nissangatvam	From good company to no company
Nissangatve nirmohatvam		From no company to lack of desire
Nirmohatve  nischaltatvam	From lack of desire to concentration of mind
Nischalatatve jeevanmuktihi	From concentration of mind to death
Newsgroups: sci.math.num-analysis
From: engp2176@nusunix1.nus.sg (JEROME HANSABHAYA ELLEPOLA)
Subject: test
Organization: National University of Singapore
X-Newsreader: TIN [version 1.1 PL6]
Date: Tue, 13 Oct 1992 08:48:35 GMT

Phi this is a test, and i aint good at VI editor yet
From: akyildiz@vax.oxford.ac.uk
Newsgroups: sci.math.num-analysis
Subject: AllRoots
Date: 14 Oct 92 16:02:22 GMT
Organization: Oxford University VAX 6620

(*
This is a Mathematics V.2:0  programme allowing  the user to 
numerically compute all the (real) roots of any continuous 
function on a given interval. Faster versions, using Secant and
Newton's methods, are also available.  Complex case is in preparation.
Text copy of the paper can be obtained from: akyildiz@maths.oxford.ac.uk

Yilmaz Akyildiz

Beware:  RealInterval builtin function is not (yet) bug-free...
*)

*)
BeginPackage["IntervalBisectionMethod`"];

intbisec::usage =
"intbisec[f, left, right, tolerance] finds all the 
(real) roots of the function f on the closed 
interval [left, right] with accuracy up to the tolerance.  
It uses a version of interval bisection method. f must be 
provided in the form f = Function[variable, body]. 
For example,
intbisec[Function[x, x Sin[x] - 1/2], Pi, 20, 0.0001]
will find all the roots of  x * Sin[x] - 1/2 = 0 on the 
closed interval [Pi, 20] with accuracy correct up to 3 
decimal digits. The output will be displayed in terms of 
the Mathematica builtin function RealInterval[{a, b}] for 
the root which is contained in the closed interval [a, b]. 
We prefer the output in this format since Mathematica can 
do arithmetic with RealInterval objects.";

Begin["`Private`"];

lefthalf[RealInterval[{x_, y_}]]    := RealInterval[{x,(x+y)/2.}];             
righthalf[RealInterval[{x_, y_}]]   := RealInterval[{(x+y)/2.,y}];             
containszero[RealInterval[{x_,y_}]] :=  (x <= 0 <= y);                         
bisect[int_RealInterval]            := {lefthalf[int],righthalf[int]};         
                                                                               
                                                                               
intbisec[f_Function, a_, b_, tol_] :=                                         
   With[                                                                       
      {step =   Select[(bisect/@#)//Flatten, containszero[N[f[#]]]&]& },          
      Nest[step, {RealInterval[N[{a,b}]]}, Ceiling[Log[2,N[(b-a)]/tol]]]             
          ];                                                                   
End[];

EndPackage[]

(* end of  IntervalBisectionMethod *)
Newsgroups: sci.math.num-analysis
From: lstern@orville.nas.nasa.gov (Louis G. Stern)
Subject: Least Squares Fitting or Cubic Splines?
Organization: Numerical Aerodynamic Simulation, NASA Ames
Date: 15 Oct 92 16:23:28
Distribution: sci.math.num-analysis

I'm posting this problem for a friend, and I don't have easy access
to usenet, so please reply by e-mail.  I will post a summary of the
replies.

The problem:  I have some reasonably good data, 2 pi periodic, which
indicates where, on the inside of a tube, there are holes and bends.
While it is perfectly obvious visually, I'd like to fit the data with
a fairly smooth curve that does *not* incorporate the holes, but *does*
capture most of the bends.  I have tried one approach:  a least-squares
fit of the data to the first 5 cos/sin frequencies, then weighting the
data inversely as their distance from the fit and trying again.  After
several iterations most of the outliers are not counted in the fit.  This
doesn't work so well when the pipe is bent, though, because the cross
section of a bent pipe incorporates a lot of high frequency information!

The other idea is this:  is there some way to pick a 'sufficient' number
of control points in the data automatically, without including the outliers
(such as might arise from pits in the pipe), and generate a cubic or
exponential spline that fits well with the rest of the data?  Has anyone
come across some combination of splines + least-squared fitting before?

I would appreciate references to articles, textbooks, et al.

L.G. 'Ted' Stern
lstern@orville.nas.nasa.gov
From: bardo@ief-paris-sud.fr (Bardo Muller)
Newsgroups: sci.math.num-analysis
Subject: Re: Interpolation on a non-Cartesian grid
Date: 7 Oct 92 08:08:13 GMT
Reply-To: bardo@ief-paris-sud.fr
Organization: Universite de Paris

Dear Ayman,

you can see this as the transition from a finite difference to a
finit element formulation.

For example, inside a triangular element, you can interpolate the values by 
a plane formula:

\begin{equation} \label{eq:phi1}
\phi(x,y) 
\,=\,  
k_1 + k_2\, x + k_3\, y . 
\end{equation}

Using the edge coordinates 
$(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3)$
you get for the edge values
$\phi_1$, $\phi_2$ et $\phi_3$

\begin{eqnarray} \label{eq:phi2}
\phi_1 &\,=\,&  k_1 + k_2\, x_1 + k_3\, y_1 \cr 
\phi_2 &\,=\,&  k_1 + k_2\, x_2 + k_3\, y_2 \cr 
\phi_3 &\,=\,&  k_1 + k_2\, x_3 + k_3\, y_3  
\end{eqnarray}

Resolve \ref{eq:phi2} for $k_1$, $k_2$ et $k_3$
and substitute in \ref{eq:phi1}, you get
the interpolation at interior points:
\begin{equation}
\phi(x,y) 
\,=\,  
N_1(x,y)\, \phi_1 +N_2(x,y)\, \phi_2 +N_3(x,y)\, \phi_3  
\end{equation}
avec
\begin{eqnarray}
	N_1(x,y)&\,=\,&\frac{y_3 x_2 - x_3 y_2 + x\,(y_2 - y_3) + y\,(x_3 - x_2)}{2\Delta} \cr
	N_2(x,y)&\,=\,&\frac{x_3 y_1 - y_3 x_1 + x\,(y_3 - y_1) + y\,(x_1 - x_3)}{2\Delta} \cr
	N_3(x,y)&\,=\,&\frac{y_2 x_1 - x_2 y_1 + x\,(y_1 - y_2) + y\,(x_2 - x_1)}{2\Delta} 
\end{eqnarray}

There, the numerator represents the determinante,

\begin{eqnarray}
2\Delta 
&\,=\,&
\left\vert
\matrix{ 1 & x_1 & y_1 \cr
	 1 & x_2 & y_2 \cr
	 1 & x_3 & y_3 }
\right\vert \cr 
& &\cr
&\,=\,&
x_2 y_3 + x_3 y_1 + x_1 y_2 - x_2 y_1 - x_3 y_2 - x_1 y_3
\end{eqnarray}

which equals the double surface of the triangle.


Hope you are helped with this.

Salut

Bardo 

============================================================================
 Bardo MULLER                          | phone  : [33] [1] 69 41 78 50    
 Institut d'Electronique Fondamentale  | fax    : [33] [1] 60 19 25 93    
 Bat. 220 Universite Paris Sud         | e-mail : bardo@ief-paris-sud.fr  
 91405 ORSAY CEDEX FRANCE              |             THE NET WORKS !      
============================================================================
From: lilau@beam.Princeton.EDU (Li Wing Lau)
Newsgroups: sci.math.num-analysis
Subject: Help:  persp() function in S
Date: 11 Oct 92 20:43:27 GMT
Article-I.D.: Princeto.1992Oct11.204327.5811
Organization: Princeton University
Originator: news@nimaster

I am using Splus to plot some 3D graphs, and I have
having trouble using the eye parameter persp() uses 
to specify the viewpoint that I want.  All I seem to
be able to get are viewpoints from either corner of
my plot.

Thanks in advance.

Li Wing Lau
From: horn@schaefer.math.wisc.edu (Jeffrey Horn)
Newsgroups: sci.math.num-analysis
Subject: Reid's Method for LU Update
Date: 15 Oct 92 15:44:00 GMT
Organization: Univ. of Wisconsin Dept. of Mathematics

Would anyone know where I can get some code that updates an LU
decomposition upon the replacement of a column in the original
matrix?  I have references to papers which discuss several methods:
Saunders' method, Bartels-Golub method, Reid's method.  I am
especially interested in implementations of Reid's method for
sparse matrices.

Jeff Horn
Newsgroups: sci.math.num-analysis
From: dabell@next09epsl.wam.umd.edu (Dan Tyler Abell)
Subject: numerical integration in several dimensions
Reply-To: dabell@quark.umd.edu
Organization: Workstations at Maryland, University of Maryland, College Park
Date: Wed, 7 Oct 1992 14:44:50 GMT

I am interested in extensions of Gaussian quadrature to several 
dimensions (sometimes called "cubature").  Can anyone tell me 
the current state-of-the-art and/or refer me to appropriate 
literature?  E-mail appreciated.  Thanks in advance.