HDTenEightyP/NetNews huggingface dataset:
From: riddle@mathcs.emory.edu (Larry Riddle)
Newsgroups: sci.math.num-analysis
Subject: Can you call IMSL from C program?
Keywords: IMSL
Date: 30 Jul 92 14:35:53 GMT
Organization: Emory University, Dept of Math and CS

I am posting this message for a friend. She would like to call
some of the IMSL routines from a C program. I suspect this should
be possible, but I'm not an IMSL expert nor a C expert. Can this
be done, and if so, how? She would be working on a Sun 4.
Any pointers (no pun intended) would be appreciated. Thank you.


Larry Riddle        | riddle@mathcs.emory.edu         PREFERRED
Agnes Scott College | {rutgers,gatech}!emory!riddle    UUCP 
Dept of Math        | riddle@emory.bitnet             NON-DOMAIN BITNET
Decatur, GA 30030   | (404) 371-6222                  AT&T
-- 
Larry Riddle        | riddle@mathcs.emory.edu         PREFERRED
Agnes Scott College | {rutgers,gatech}!emory!riddle    UUCP 
Dept of Math        | riddle@emory.bitnet             NON-DOMAIN BITNET
Decatur, GA 30030   | (404) 371-6222                  AT&T
From: ajayshah@almaak.usc.edu (Ajay Shah)
Newsgroups: sci.math.num-analysis
Subject: Question(s) on approximation using orthogonal polynomials
Date: 28 Jul 1992 02:39:12 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: almaak.usc.edu

I'm trying to use orthogonal polynomials to approximate the value
function of a dynamic programming problem.  I am having problems
choosing the right polynomial.

I'm trying to approximate a function f(x), and x generally takes
values from roughly -10 to +200.  But the theory of this problem says
that x is unbounded in the +ve direction.

I plan to evaluate the fourier coefficients of the approximation rule
using quadrature, so if I use N points in the rule, that gives me the
N values of x at which I need to evaluate f(x).

1. It still seems like black magic to me that out of N values of f(x),
I am getting a approximation rule which claims to know f(x)
everywhere.  What are the caveats of such a claim?

2. What weight function and orthogonal polynomial should I use?  The
approximation theory says that the error of the truncated summation is
minimised in a least squares sense with respect to the weight
function.  Because I may never need to calculate f(x) for x outside
[-10, 200], is it theoretically correct to just use a Legendre
polynomial or a Chebyshev polynomial, using a simple scaling to
convert [-1, 1] into [-10, 200]?

3. How does one choose between Legendre and Chebyshev?  Legendre has a
weight function w(x) = 1, which makes sense to my approximation needs.
Chebyshev has the attractive property of lower computational cost and
smaller error.

4. What are the pitfalls of extracting derivatives out of the
approximation?

5. If I must use the Laguerre polynomial, which is defined on 
[0, infinity], then where do I find out the recurrence relation 
for evaluating it?

Thanks,

        -ans.


-- 
Ajay Shah, (213)749-8133, ajayshah@usc.edu
Newsgroups: sci.math.num-analysis
From: rcpshdb@dutrun2.tudelft.nl (Han de Bruijn)
Subject: Re: PC software to do Partial Diff EQ's ?
Originator: rcpshdb@dutrun2.tudelft.nl
Reply-To: rcpshdb@dutrun2.tudelft.nl (Han de Bruijn)
Organization: Delft University of Technology
Date: Thu, 23 Jul 1992 07:08:07 GMT

In article <1992Jul22.111404.16892@eagle.lerc.nasa.gov> Herb Schilling:
> A while ago I asked if there are any PC packages ( commercial or freeware ) 
> to do partial differential equations ? [ ... ]

>  The only response that I got was posted to this newsgroup. [ ... ]

Ah, and you have such a nice employer ... : Nasa's NASTRAN solves such
partial differential equations. Many other expensive Structural Mechanics
packages do it, such as ANSYS and MARC. The PHOENICS package solves it's
P.D.E.'s in the Computational Fluid Dynamics area, among others such as
FIDAP and FLOTRAN. For Electronics, you can buy finite element codes from
a company called TMA: PISCES, SUPREM and others. They all cost money.

But there is NO such thing as a Universal Partial Differential Equation 
Solver available anywhere. All serious packages are specializations for
a certain area of interest: Mechanics, Fuids, Electronics. No freeware.
Some of these can be ordered for PC's too, yes.

Take my advice: if you ever want to get a sensible answer, be (far) more
specific: _which_ (system of) P.D.E.'s do you want to solve?
In _what_ kind of applications area?
-- 
* 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
Xref: sparky sci.math.num-analysis:2294 comp.lang.c++:11568
From: anthonyb@cs.uq.oz.au (Anthony Bloesch)
Newsgroups: sci.math.num-analysis
Subject: Re: An efficient way of finding the the delta of two numbers
Date: 22 Jul 92 00:09:45 GMT
Reply-To: anthonyb@cs.uq.oz.au

In <BrpsJC.5HE@cs.columbia.edu> amir@cs.columbia.edu (Amiran Eliashvili) writes:


>Hi all:

>	I am trying to come up with an efficient way (fewest number of
>iteration ) to find in a list of numbers (not sorted) two numbers
>whose delta (x - y) is the least. So far I could see O(n^2) and
>possibly n*log(n). Are there any kind souls out there that know of a
>better methods that will improve on the above number of iterations?

Interesting problem.  I would guess the best way boils down to sorting
the list and then running  through  it looking for  the number that is
closest to it's successor.  Now this  can be done in  O(n log  n) time
with no real memory overhead by quicksort.  But since they are numbers
we can do it in O(n) time with a radix or distribution sort.  Thus you
are looking at O(n) time.  It seems to me that you will not  do better
than this.

                                       Anthony
Xref: sparky sci.math.num-analysis:2293 comp.lang.c++:11567
Newsgroups: sci.math.num-analysis,comp.lang.c++
Subject: Re: SUMMARY: Automatic differentiation
From: robertd@kauri.vuw.ac.nz (Dr R Davies*xrbd*)
Date: Sun, 26 Jul 1992 00:25:44 GMT
Organization: Victoria University of Wellington, New Zealand

In article <l71d15INNakq@almaak.usc.edu> ajayshah@almaak.usc.edu (Ajay Shah)
   writes:
>A few days ago I asked for information on software to do
>"automatic differentiation".  For the uninitiated, this is a way to
>get exact derivatives of any order without needing to analytically
>evaluate the formulas for the derivatives.
>..........
>It looks like the best way to do automatic differentiation is to use
>C++.  What follows gives you some pointers to software available.
>It looks like the people who write matrix libraries in C++ have not
>talked a lot with the people who do automatic differentiation in C++
>:-)  Please do so!

Could you explain the connection with matrix packages a little more.

To do symbolic manipulation in C++ you will probably want to use the kind of
representation I use in my matrix package, Newmat. Of course the basic
concept in that representation is taken from the reading I have done about
symbolic manipulation.

The problem is that actually evaluating the expressions you get will be quite
slow because the computer will have to interpret the representation of the
expression as well as do the arithmetic. This is not a problem with your
main function (if you are doing maximisation or solving) because you can
use templates to get both the symbolic representation and an efficiently
compiled expression. But with the derivatives you are stuck with the symbolic
expressions. Of course if your variables are matrices rather than reals,
then the efficiency is not a problem because the matrix computation times
will overwhelm the interpret times.

So there are at least two connections with matrices - is this what you had in
mind.

Now for a short comnmercial break:

I agree that C++ is almost an ideal language for doing this kind of thing;
having the structure to do both symbolic manipulation and numerical
manipulations.

But much work with equations will involve powers (the fortran ** operator)
and at the moment C++ does not have the power operator.

I am still interested in putting the case together for a power operator if
no-one else will do it and would be interested if people interested in
symbolic manipulation have any comments.


Thanks for your list of responses and references.

Robert
Newsgroups: sci.math.num-analysis
From: ping@hub.toronto.edu (Ping Lin)
Subject: Eigenvector routine in C
Organization: CSRI, University of Toronto
Date: 27 Jul 92 13:50:48 GMT

I am looking for a C routine to find the eigenvectors of small, real matrices.
Does anyone know if such a beast exists on the net somewhere?
Thanks in advance,

Ping
Newsgroups: sci.math.num-analysis
From: pssres12@ucs.usl.edu (Vignes Gerard M)
Subject: Re: Imaginary Numbers in C
Organization: Univ. of Southwestern La., Lafayette
Date: Sun, 26 Jul 1992 16:28:48 GMT

In article <92208.174123K3006E7@ALIJKU11.BITNET> <K3006E7@ALIJKU11.BITNET> writes:
>I am very unfamiliar with the C language, so I beg your indulgence.

	If you're going to go to all that trouble,
	you might as well do it right.

	Learn C++ instead of C.

	You can declare your own types (like complex and imaginary)
	and then overload the conventional operators
	+, -, *, /, to handle them easily and transparently
	(even in combination with other numeric types).

	Don't waste your time on C.


-- 

                Mai, y'all hab'en lisd'nen ta d'voice ah

                         RADIO FREE LAFAYETTE
From: sarath@pender.ee.upenn.edu (P. Sarath Kumar)
Newsgroups: sci.math.num-analysis
Subject: How do I solve this non-linear Problem?
Date: 30 Jul 92 16:14:54 GMT
Reply-To: sarath@pender.ee.upenn.edu (P. Sarath Kumar)
Organization: University of Pennsylvania

The equation that I have is

A x + m z = b

where m is a real scalar and all others have complex elements.

A is a square matrix, b, x are column vectors. x is the vector 
to be solved for and the elements of z are related to those of 
x by zi=xi/magnitude(xi) where xi and zi are the i th elements 
of x and z respectively. In addition, A is a hermitian matrix. 

The dimensions of the above matrices are very small (could be
as low as 2). 

What kind of methods can I use to solve this problem? I
know this can be solved by least squares method. But  
are there any numerical routines which can give all the
solutions? If yes, what are they and where do I get them?

I am not very well-versed with numerical methods so any
references in this regard would also be helpful. (Can this
problem be solved analytically?)

Thank you,

Sarath.
sarath@pender.ee.upenn.edu

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
P. Sarath Kumar      314, Moore School, 200 S.33rd St.,  Philadelphia, PA19104.
		     Ph: Off (215)-898-4183.  Res: (215)-387-1880.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



____________________________________________________________________
   __       __                    
  /     /| |  |                                                          
  --   /_| |--
From: sost@barney.cs.utk.edu (Susan Ostrouchov)
Newsgroups: sci.math.num-analysis
Subject: FORTRAN source for LINPACK/EISPACK
Date: 31 Jul 92 15:53:10 GMT
Organization: University of Tennessee, Knoxville - Department of Computer Science
Distribution: world
Reply-To: sost@barney.cs.utk.edu (Susan Ostrouchov)
NNTP-Posting-Host: barney.cs.utk.edu

 
Keywords: 

Fortran source for LINPACK, EISPACK, and LAPACK can be obtained
from netlib@ornl.gov.  Send email to netlib and in the message type:
send index from linpack
or 
send index from eispack
or 
send index from lapack

for the appropriate index file of available routines.

Susan Ostrouchov...
Newsgroups: sci.math.num-analysis
From: xu@math.psu.edu (Jinchao Xu)
Subject: 7-th Conference on Domain Decomposition Methods
Reply-To: xu@math.psu.edu
Organization: Dept. of Mathematics, Penn State University
Date: Tue, 28 Jul 1992 20:27:52 GMT

The Seventh International Conference on Domain Decomposition Methods
will be held at Penn State during the four-day period October 27--30, 1993.
If you want to receive further information, please contact: R. Manning (secretary), 
Dept. of Math., Penn State Univ., University Park, PA 16802. Tel: 814-865-7527;
Fax: 814-865-3735; Email: ddm7@math.psu.edu.
From: K3006E7@ALIJKU11.BITNET
Newsgroups: sci.math.num-analysis
Subject: Imaginary Numbers in C
Date: 26 Jul 92 22:41:23 GMT
Organization: Johannes Kepler University Linz - Computing Center

I am very unfamiliar with the C language, so I beg your indulgence.
I normally work with math packages such as "MATLAB", but because of
its relatively slow speed on some routine loops, I thought it would
be good to write them in C.  But I found out that unlike Fortran, C
does not, as far as I could see, data type for imaginary numbers.
Or am I completely wrong?  Would I have to work with "structures"
and redefine most operations such as *,+,-, etc. to work with these
structures?
Help would greatly be appreciated!
From: luk@ohstpy.mps.ohio-state.edu
Newsgroups: sci.math.num-analysis
Subject: CM-2 reference manual
Date: 30 Jul 92 19:23:46 EDT

hello, I am not sure this is the right news group to post...
Can anyone tell me where I can have Connection Machine Fortran 
Programmer's Reference Manual, or any reference related to that.
many thank...
From: st_waldman@zodiac.dsto.oz.au
Newsgroups: sci.math.num-analysis
Subject: Wanted: Hilbert transform source code
Date: 30 Jul 92 05:41:32 GMT
Organization: D.S.T.O. Aeronautical Research Laboratory

I am looking for a Hilbert transform routine to enable me to compute
the phase response from a magnitude-only frequency response function.
It should be able to deal with bandpass response functions, such as
those obtained from electrical filters and loudspeakers. I also wish
to apply it to determine phase information from impedance magnitude
response data. Any source code would be appreciated. I can handle
Pascal or Fortran, and C can also be used. 

Thank you...

Witold Waldman
ST_WALDMAN@ZODIAC.DSTO.GOV.AU
Newsgroups: sci.math.num-analysis
From: amell@nyx.cs.du.edu (Andrew P.Mell)
Subject: Transmission Line Matrix Method - code needed
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Wed, 22 Jul 92 02:14:29 GMT

This is probably a very long shot, but does anyone have some code relating
to the transmission line matrix method, completeness is optional.

I'd be very grateful for any responses. Email or otherwise.

Thanks

Andy
Xref: sparky sci.math.num-analysis:2259 sci.math:9373 sci.physics:11269
From: dfoster@maths.tcd.ie (Duncan Foster)
Newsgroups: sci.math.num-analysis,sci.math,sci.physics
Subject: help on rebining
Date: 21 Jul 92 17:40:38 GMT
Organization: Dept. of Maths, Trinity College, Dublin, Ireland.

I need to find out about a technique called rebining in a hurry. Could
anyone point me to a good reference on the subject? Or better still a quick
summary would be useful. E-mail replys please as I don't read
sci.math.num-analysis.


Thanks in advance,

Duncan Foster
From: sasha@ldgo.columbia.edu (Alexander Krupitsky)
Subject: Optimization program wanted
Organization: Lamont-Doherty Geological Observatory
Date: Thu, 23 Jul 1992 17:47:45 GMT

Hi,

I am looking for a program which would minimize quadratic (convex)
function under convex constrains.

Please email to sasha@rainbow.ldgo.columbia.edu

Thank you in advance.


				Sasha

Newsgroups: sci.math.num-analysis
From: dobrohoczkim@cc4.crl.aecl.ca
Subject: Finding Precentage Points of a PDF
Organization: AECL RESEARCH
Date: Wed, 29 Jul 1992 14:23:00 GMT

I am looking for algorithm that will find the precentage points of a p
probability distribution function. Namely a algorithm that when given a
percentage value and a PDF f(t) return x such that the integral from negative
infinity (or zero in my case) to x of f(t)dt is the given percentage value.
Any help will be appreciated.

Thanks,

dobrohoczkim@crl.aecl.ca
Mike Dobrohoczki
Chalk River Laboratories
Atomic Energy Canada Ltd.
Newsgroups: sci.math.num-analysis
From: amell@nyx.cs.du.edu (Andrew P.Mell)
Subject: Genetic Algorithms
Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept.
Date: Tue, 28 Jul 92 02:55:03 GMT

I'm very interested in the subject of Genetic Algorithms, could someone
point me towards an introductory paper on the subject, and perhaps
(if I'm lucky!) some C code....?

Thanks

Andy
(Email if you like - I _will_ summarise to the group if there is sufficient
interest)
Newsgroups: sci.math.num-analysis
From: kurtles@momth3.maths.monash.edu.au (Mr K.A. Brinschwitz)
Subject:  REQUEST:General network solver
Keywords: General networks; Optimization
Organization: Monash University
Date: Tue, 28 Jul 1992 07:55:49 GMT

	I am interested in obtaining either C or FORTRAN coding for
a generalized network solver. The particular problem of interest is 
this:
	Consider a directed graph with set of nodes, N, and  a set of arcs, ARCS.
Each arc, (i,j), has a scalar associated with it, Aij   , the COST of (i,j).
Let Fij  denote the FLOW on arc (i,j). There are upper and lower bounds on Fij,
Cij and Lij respectively.

With each arc (i,j),  there is an associated scalar Kij, the GAIN of arc (i,j).

The problem:
                 _
      minimize   > Aij Fij
                 -
         (i,j) element of ARCS


subject to

         (Conservation of flow)
          _                               _
          >  Kmi  Fmi          -          >  Fim          =  0    (For All i in N)
          -                               -
          m                               m
   (m,i) element of ARCS        (i,m) element of ARCS

       
          (capacity constraints)

          Lij <=  Fij   <=  Cij        (for all (i,j) in the set ARCS)	   

------------------------------------------------------------------------------------

I am interested in obtaining a network solver that handles the above for 
cases with  Kij not always unity (ie networks with gains and losses.)

I already have a paper by Bertsekas and Tseng (OPERATIONS RESEARCH, VOL36 No 1
1988),  in which an algorithm is formulated for solving a network with Gains.
Does anyone know if the algorithm has been coded ? I know that they have already 
coded a solver for a zero-gain network.

Any help gratefully recieved.

Kurt Brinschwitz.







Newsgroups: sci.math.num-analysis
From: frank@unixg.ubc.ca (Murray Frank)
Subject: Re: Choice of optimization methods
Organization: University of British Columbia, Vancouver, B.C., Canada
Date: Wed, 22 Jul 1992 00:29:23 GMT

In article <15381@ucdavis.ucdavis.edu> JRBANGA@poppy.ucdavis.edu (JULIO RODRIGUEZ BANGA) writes:
>
> Hi there.
>
>  There is a huge amount of literature reporting the solution of optimization
>problems using genetic algorithms and direct search optimization methods (like
>the Complex from Box) that are more or less 'stochastic'.
> 
> I'm myself a user of this type of methods because they are usually easy to
>work with and, more important, they usually work well, if you don't mind CPU
> time very much. 
>
> However, these methods are usually regarded as 'politically incorrect', and
>considered as 'inferior' when compared with, for example, SQP (sequential
>quadratic programming) and gradient methods. For those interested, see the
>comments of Dr. Sargent in the book 'Foundations of computer-aided process
>design', edited by Sirola, Grossman and Stephanopoulos, CAChE-Elsevier, 1990.
>
> Though my work deals with optimization, I'm not an expert in the field, so I'd
>like to receive opinions about the pros and cons of GA and direct search
>methods when compared with 'politically correct' algorithms. Particularly, 
>if those methods are 'incorrect', why are they so widely used?.

What is "widely used" seems to depend on the field of study. In the
literature that I am familiar with (economics) the Genetic Algorithm 
is not widely used. When used, it seems mainly to be used in order to 
find a starting value for a more conventional algorithm. Or, from the
reverse perspective, the conventional algorithms (gradient based) are 
being used to locally improve the result of the GA. 
Newsgroups: sci.math.num-analysis
From: schultz@halley.est.3m.com (John C. Schultz)
Subject: Re: Maximize Volume of Boxes in Shipping Container
In-reply-to: mjfrisch@vx.cis.umn.edu's message of Fri, 24 Jul 1992 17:57:00 GMT
Organization: 3M Company, 3M Center, Minnesota, USA
Date: Sat, 25 Jul 92 02:44:45 GMT

In article <24JUL199212572842@vx.cis.umn.edu> mjfrisch@vx.cis.umn.edu (Michael J. Frisch, CIS 612/625-5830) writes:

   I am helping one of our users who wants to get the maximum volume of boxes
   to fit in a shipping container.  There are twelve different sized boxes.
   I'm interested in any software for solving this problem.  Otherwise, is
   there a way to set this up as a linear or nonlinear programming problem?
   If so, how?  Are there other methods one could use?  Are there any
   published articles or books on the subject?  Thanks for your help.

This problem is various referred to as a bin-packing or the knapsack problem.
General unconstrained solutions are very difficult to obtain.  Fortunately you
can do pretty well by imposing conditions and getting a good, albeit
non-optimal solution. Refer to the following letter that I had obtained about a
year ago.

BTW, I was trying to apply genetic algorithms to this problem but lacked a
good mutation and cross-over technique to prevent boxs (or squares in the 2D
case) from falling outside the boundaries.  Without this you end up wasting
most of the time on impossible combinations (unless you don't mind boxes
slopping over the side of the truck :-)


----------------------------------------------------------------------
Return-Path: <peter@bacchus.esa.oz.au>
Date: Fri, 19 Apr 91 12:04:10 EST
From: peter@bacchus.esa.oz.au
Apparently-To: schultz@halley.serc.3m.com

John,

In sci.math.num-analysis you write:

>Does anyone have suggestions on optimal packing techniques?

>Specifically I am interested in how to maximize the number of
>arbitrary sized rectangles which can be positioned anywhere on a
>larger, arbitrary sized rectangle.

>Thanks for any help.
>--
>John C. Schultz                    EMAIL: schultz@halley.serc.3m.com


>From what I've seen ,it appears that optimal 2d packing is very expensive and 
most of the algorithms use simplifications such as a guillotine-cutting 
methodology. (I'm working on an automated publication layout system)

References I have found useful are

1) Christofides, N. and Whitlock, C.: An algorithm for the two-dimensionsal
	cutting problem, Ops. Research 25 (1977) 30-44

2) Gilmore P.C. and Gomory R.E. : Multistage cutting stock problems of two and 
	more dimensions, Ops Research ?? 94-120 (See reference in 1)

The above two wrote a number of papers on the Knapsack problem which is related
but imposes no constraints on the number of each size of object. (See 
references in 1)

Hope you find them of some use,

	Peter Davison,
	Expert Solutions Australia.

--
   John C. Schultz   +1 (612) 733-4047   schultz@halley.serc.3m.com
   How to include the taste of Glendronach in a multi-media system?