Subject: NA-NET distribution message

From: [email-masked]
Date: Sun, 1 Oct 89 23:13:24 PDT

NA Digest   Sunday, October 1, 1989   Volume 89 : Issue 38

Today's Editor: Cleve Moler

Today's Topics:

     Software for Mixed Integer Programming Problem
     Fluid Dynamics Conference at Oxford 
     MATLAB User's Group
     Generating Eigenvalues in a Particular Order
     Out of Core Solvers
     Multi-dimensional Quadrature Software
     Replacement of EISPACK RSP
     Position at Argonne
     Positions at Boeing Computer Services
     Position at NC State

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

From: Steve Horne <[email-masked]>
Date: Mon, 25 Sep 89 09:20 EDT
Subject: Software for Mixed Integer Programming Problem

I have the following problem in Mixed Integer Linear Programming.

    S_0 is a point (vector) in Euclidean n-space En
    A is an n x m matrix containing m vectors in n-space, m>n.
    d is a vector of m distances from S_0 to each column in A
    x is an unknown vector of m weights, n+1 of which are gt 0, the rest
      zero
    y is an unknown vector whose components contain (n+1) ones 
      and (m-n-1) zeros.
    e is a vector with m components, all ones.
    
                    The Problem:

                    minimise d.y
    with constraints
                    A.x = S_0 
                    e.x = 1
                    x le y
                    y is (0,1)
                    x ge 0

In words, select from m points the n+1 points whose convex hull contains
S_0, and the sum of whose distances from S_0 is a minimum.

Typical dimensions -- S has 5-7 components; m is about 30.

        I need a subroutine which solves the above, preferably in Fortran or C.
 Ideally, the routine would not be a general mixed integer routine, but would
take advantage of some of the special structure.  However, I'll take anything I
can get.  The application is approximation of a function whose value is
known in scattered points in n-space.  The subroutine(s) would become part of a
package to be used in programming the feedback control computer for Alcator
C-Mod, a tokamak under construction at MIT.  Any contribution used in the
package will be carefully and gratefully acknowledged. 

Thanks for your help
    Steve Horne
    (617) 253-8663
    [email-masked]

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

From: Bette Byrne <[email-masked]>
Date: Mon, 25 Sep 89 15:07:21 BST
Subject: Fluid Dynamics Conference at Oxford 
        
                  12TH INTERNATIONAL CONFERENCE ON
                 NUMERICAL METHODS IN FLUID DYNAMICS
        
                        University of Oxford
                            9-13 July 1990         
        
The conference will cover all areas of Computational Fluid Dynamics with 
particular emphasis on:

      Algorithm Development        Parallel Computing
      Hypersonic Flows             Transition and Turbulence
      Environmental Flows          Propulsion Systems

It will be held in the Lecture Theatre of the Zoology and Psychology Building
and hosted  by the Computing Laboratory, Department of Engineering Science
and the Mathematical Institute.  Accommodation has been arranged in a number
of Oxford colleges and the Randolph Hotel for the duration of the Conference.
Details of this and other accommodation in Oxford or its surrounding
countryside will be made available upon request.  

There will be six invited speakers as well as contributed  papers.  Two page
abstracts (including sample figures) of contributed papers should be submitted 
before December 8, 1989: five copies are required.  Notifications of acceptance 
will be given by March 12, 1990.  Camera ready copies of the final manuscript 
will be due at the conference for publication in the proceedings.  Abstracts 
should be submitted according to the author's home country as follows:

    USA                              USSR and Eastern Europe
    Professor M Holt                 Professor V Rusanov
    Dept of Mechanical Engineering   Keldysh Inst Appl Mathematics
    University of California         Miusskaya Pl.4
    Berkeley,CA 94720                125047 Moscow A-47

    India, Asia, Pacific Rim         Canada, Western Europe, Israel 
    Professor K Oshima               (and all other countries)           
    Inst Space & Astro Science       Professor R Temam    
    3-1-1 Yoshinodai                 Laboratoire D'Analyse Numerique
     Sagamihara                      Universite Paris Sud/Bat.425
    Kanagawa 229, Japan              91405 Orsay, France

A limited number of bursaries will be made available to young potential 
contributors born after 9 July 1960.  Applications with abstracts should be
sent to Prof. P. J. Zandbergen, Department of Applied Mathematics,
Twente University Technology, PO Box 217, 7500 AE Enschede, The Netherlands.

For further details contact:

    Mrs Bette Byrne
    Institute for Computational Fluid Dynamics
    Oxford University Computing Laboratory
    8-11 Keble Road
    Oxford OX1 3QD
    Tel.+44-865-273883
    Fax.+44-865-273839

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

From: Chris Bischof <[email-masked]>
Date: Tue, 26 Sep 89 09:27:53 CDT
Subject: MATLAB User's Group

In response to an initiative by Howard Wilson from the University
of Alabama, there is now a MATLAB User group mailing list and
software repository. If you are interested in joining and are not
on the mailing list yet (i.e. you have not yet received the message
describing the setup of the user group and library), send a message
to 
	[email-masked]
and I will add you to the mailing list and send you information
about the mailing list and library.
	-- Chris Bischof
	   Mathematics and Computer Science Division
	   Argonne National Laboratory
	   Argonne, IL 60439
	   (312) 972-8875
	   [email-masked]

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

From: Farid Alizadeh <[email-masked]>
Date: 26 Sep 89 19:44:54 GMT
Subject: Generating Eigenvalues in a Particular Order

Here is a problem I have come across in the course of some optimization
problem. 
Let A(x) be a real, symmetric n x n matrix  with some or all of its entries
variables. (the vector x consists of variables from the first row to the last
and in each row from the first column to the last. Also, since the matrix
is symmetric the variable at ij entry is the same as the variable at ji.)
It is well-known that the eigenvalues of A(x) are real valued continuous
and smooth functions of x. At a given point x_0 compute the eigenvalues
and impose an arbitrary order on them; so we will get l_1(x_0), l_2(x_0),
..., l_n(x_0). Now compute the eigenvalues at new points x_1, x_2, ...,
x_k, ... The problem is that at each new point x_k I also need to compute a
permutation that reorders eigenvalues so that all eigenvalue 
functions l_r are continuous and smooth. That is
l_r(x_0), l_r(x_1), ..., l_r(x_k), ...
are the values of the SAME continuous and SMOOTH function. For a simple
example consider the matrix with one variable:
			1   x
			x   1
Then, the eigenvalues of this matrix are:
l_1(x)=1+x
l_2(x)=1-x.
Now, for various values of x, say, QR method sometimes produces l_1(x) as the
first eigenvalue and sometimes l_2(x). This is true of just about any other
algorithm that I am aware of. (Notice that eigenvalues generated in increasing 
or decreasing order do not represent smooth functions.)
The problem is this: Assuming that we can easily compute the eigenvalues 
with enough precision, how can I reorder the eigenvalues at each x_k
so that the r'th eigenvalue in my list  is the value of the continuous and  
smooth function l_r.

Does anyone know how to do this or know of any reference?

    Farid Alizadeh
    CSci Dept., University of Minnesota, Mpls.

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

From: Jeff Simon <[email-masked]>
Date: Thu, 28 Sep 89 07:22:21 CDT
Subject: Out of Core Solvers

I am seeking information on software for the solution of non-symmetric
linear systems implemented for out of core operation.  The matrix is 
banded and solver may be direct or iterative.  I greatly appreciate
information forwarded and replies may be sent to:

simon.ncsa.uiuc.edu

Thank you,
    Jeff Simon

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

From: George Corliss <[email-masked]>
Date: 28 Sep 89 03:06:58 GMT
Subject: Multi-dimensional Quadrature Software

I would appreciate pointers to public domain software (Fortran
preferred) for multi-dimensional quadrature.  I checked netlib, but
did not see anything promising.  Did I miss something?  The 
application in question is 4-dimensional.  The integrand is 
moderately smooth, of no special form.

Thanks in advance.

George Corliss, Marquette University, Milwaukee, WI  53233
[email-masked], ...!uwvax!marque!georgec, [email-masked]

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

From: Jerzy Wasniewski <[email-masked]>
Date: Thu, 28 Sep 89 13:23:44 EDT
Subject: Replacement of EISPACK RSP

What we need is an (IEEE 64-bit) accurate, more efficient replacement of the
RSP EISPACK routine which calculates the eigenvalues and eigenvectors of a
dense, real symmetric (packed) matrix.  The algorithms used by RSP are Fortran
translations of the ALGOL TRED3, TQL2, and TRBAK3 procedures described in
Num. Math. 11 (1968) authored by Bowdler, Martin, Reinsch, and Wilkinson.

Jerzy Wasniewski
c/o Multiflow Computer, Inc.,
31 Business Park Drive,
Branford, CT 06405, U.S.A
Tel. office:           203 488 6090
Tel. home (temporary): 203 387 0171
Email address: 
            [email-masked]
or
         [email-masked]

[Editor's comments: What's wrong with RSP?  How much more efficient,
or more accurate, do you want or expect?  RSP is pretty hard to beat.
Some speedup is available by replacing the QR accumulation of
transformations by inverse iteration using the EISPACK path TRED3,
IMTQLV, TINVIT, TRBAK3.  Humberto Madrid wrote a Ph. D. thesis at
the University of New Mexico four years ago where he investigated
"perfect shifts" and "fast Givens" transformations.  Jack Dongarra
and Danny Sorensen at Argonne have been touting a divide and
conquer approach for several years.  Some recent contributions
by Peter Tang at Argonne and by W. Kahan at Berkeley appear to
guarantee orthogonal of eigenvectors.  This approach should find
its was into LAPACK, now under development at Argonne, NYU and NAG.
I guess all this may lead to a 20 to 40% improvement in execution
time, and about the same accuracy, as RSP.  That's certainly
worthwhile, but you'll have to wait a little while to have portable,
robust software comparable to that in EISPACK.  --Cleve Moler.]

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

From: Jorge More <[email-masked]>
Date: Wed, 27 Sep 89 14:45:16 CDT
Subject: Position at Argonne

                   ARGONNE NATIONAL LABORATORY
            MATHEMATICS AND COMPUTER SCIENCE DIVISION
                  Advanced Scientific Computing

The Mathematics and Computer Science (MCS)  Division  of  Argonne
National  Laboratory  invites  applications  for  a regular staff
position  in  the  area  of  advanced  scientific  computing  and
parallel   architectures,   with  emphasis  on  numerical  linear
algebra,  optimization,  or   partial   differential   equations.
Qualified  candidates will also be considered for the position of
Scientific Director of the Advanced Computing Research Facility.

Applicants with a Ph.D.  in  (applied)  mathematics  or  computer
science will be given preference; however, outstanding candidates
with degrees from other  disciplines  will  be  considered.   The
position requires extensive knowledge of methods of computational
mathematics,   intimate   knowledge    of    advanced    computer
architectures,   and   familiarity   with   modern  visualization
techniques.   Applicants  must  have  an  established  record  of
research   accomplishments,   as  evidenced  by  publications  in
refereed journals and conference proceedings.

The MCS Division  offers  a  stimulating  environment  for  basic
research.   Current  research  programs  cover  areas  of applied
analysis, computational mathematics,  and  software  engineering,
with  emphasis  on  advanced  scientific computing.  The division
operates the Advanced Computing Research Facility  (ACRF),  which
comprises  a  network of advanced-architecture computers, ranging
from an 8-processor Alliant FX/8 to a 16,384-processor Connection
Machine  CM-2.   A  network of Sun and NeXT workstations supports
the general computing needs of the division.   Argonne's  central
computing facilities include a CRAY X/MP-14; additional access to
supercomputers is provided through the major networks.

The Scientific Director of the ACRF is  responsible  for  keeping
abreast  of current developments in advanced scientific computing
and maintaining the facility and the  research  program  that  it
supports  in  the  forefront  of  computer  science research. The
Director is assisted by a Deputy Scientific  Director.  The  day-
to-day  operation  of  the  facility is the responsibility of the
Manager of the MCS Computing Facilities.

Argonne is a multipurpose national  laboratory  operated  by  The
University  of  Chicago for the U.S. Department of Energy.  It is
located 25 miles southwest of Chicago.

Applicants are requested to send a detailed resume to Rosalie  L.
Bottino,  Employment  and  Placement, Box J-MCS-37017-83, Argonne
National Laboratory, 9700 S. Cass  Avenue,  Argonne,  IL   60439.
Further  information  about the position can be obtained from Dr.
Hans  G.  Kaper,  Director,  MCS  Division   ([email-masked]),
telephone   312-972-7162.   Argonne   is  an  equal  opportunity/
affirmative action employer.  Women and minorities are especially
encouraged to apply.

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

From: Roger Grimes <[email-masked]>
Date: Thu, 28 Sep 89 06:45:06 PDT
Subject: Positions at Boeing Computer Services

                       Applied Mathematics
                     Boeing Computer Services

The Applied Mathematics group in Boeing Computer Services, 
located in Seattle, Washington, anticipates openings in early 
1990 for well qualified individuals in applied numerical 
analysis, especially numerical linear algebra.  We are looking 
for entry level or experienced PhDs with either a dissertation or 
post-graduate experience in numerical analysis and an interest in 
applying this experience to challenging real world problems.  
Problems will be oriented towards applications of numerical analysis 
but will include parallel computing and the environment for large 
scale computation, with concerns for distribution of tasks and 
visualization. 

Our group consists of about 40 mathematicians performing 
consulting and research work for other parts of The Boeing 
Company, for commercial customers, and for governmental agencies.  
We require individuals capable of working independently in a 
dynamic, multidisciplinary environment on complex algorithm, 
analysis, and application software problems.  Permanent U.S. 
residency is required; U.S. citizenship is perferred. 

Qualified applicants should send a resume to: 

                    Roger G. Grimes
                    Manager, Computational Mathematics
                    Boeing Computer Services
                    P.O. Box 24346, M/S  7L-21
                    Seattle, WA  98124-0346
                    USA

Questions regarding the position may be sent, via e-mail, to 
Roger Grimes at [email-masked] or 
[email-masked].

Boeing is an Equal Opportunity Employer.

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

From: Tim Kelley <[email-masked]>
Date: Sun, 1 Oct 89 14:03:17 EDT
Subject: Position at NC State

                  NORTH CAROLINA STATE UNIVERSITY
                     Department of Mathematics

   Our department intends to make a senior level appointment in PDE-related
applied mathematics, beginning in the Fall of 1990. Mathematical analysts
working on optimization or control problems and related computational
questions are especially encouraged to apply. Candidates must
have outstanding research credentials and a demonstrated competence in
teaching. Send a vita and arrange to have at least three letters of
recommendation sent to: J.C.Dunn, Search Committee Chairman, Department of
Mathematics, Box 8205, North Carolina State University, Raleigh, NC 27695-
8205. Address electronic mail inquiries to [email-masked].
The closing date for applications is January 26, 1990. North Carolina
State University is an equal opportunity / affirmative action employer.

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

End of NA Digest
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