Subject: NA Digest V87 #66

From: NA Digest <[email-masked]>
Date: Fri 21 Aug 87 18:06:03 PDT

NA Digest   Friday, August 21, 1987   Volume 87 : Issue 66

This weeks Editor: Cleve Moler

Today's Topics:

                    Parallel and Vector Algorithms
                    Ulrich Hornung Address Change
                         GAUSS and PC-MATLAB
                      B. and K. Datta visit UCSD
               Chicago Conference Honoring Jim Douglas
       Domain Decomposition Conference, UCLA, Jan 14-16, 1988.
              Availability of SCHEDULE package on Netlib

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

Date:    13 Aug 1987  5:03 PM CST
From:    FLORIAN A. POTRA <[email-masked]>
To:      [email-masked]
Subject: Parallel and Vector Algorithms

   This Fall I will be teaching a graduate course on "Parallel & Vector
Algorithms in Scientific Computing". During the semester the students
will have to complete individual projects on the Alliant FX/8 and the
Encore Multimax machines at the High Speed Computing Facility of the
University of Iowa. I would like to introduce my students to the newest
algorithms which are suitable for these machines. Therefore I would
appreciate very much any recent reprints and/or preprints of papers
related to the subject of the course as well as any computer programmes
in FORTRAN or C. My address is:

            Florian A. Potra            e-mail:
            Dept. of Mathematics        [email-masked]
            University of Iowa
            Iowa City, IA 52242         tel: (319)335-0776

   With many thanks in advance, F.A.P.

   P.S. We are not able to print TEX documents at U of I.

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

DATE:    14 AUG 87 17:03 CET
TO: [email-masked]
FROM: [email-masked]
SUBJECT: Ulrich Hornung Address Change

ULRICH HORNUNG
SCHI
P.O. BOX 1222
D-8014 NEUBIBERG
WEST GERMANY

TELEPHONE: 089-6004-3386
TELEX: 5215800 BW D (MUNICH)
ARPA: NA.HORNUNG AT SCORE.STANFORD.EDU

SUBJ.: TEMPORARY CHANGE OF ADDRESS

DEAR COLLEAGUE,

PLEASE NOTE THAT MY ADDRESS FROM SEPT. 1, 1987 THROUGH MAY 15,
1988 WILL BE

          DEPARTMENT OF MATHEMATICS
          ARIZONA STATE UNIVERSITY
          TEMPE, AZ 85287 U.S.A.

          TELEFONE 001-602-965-3951
          TELEX 1561058 ASU UT
          ARPA: NA.HORNUNG AT SCORE.STANFORD.EDU

SINCERELY
ULRICH HORNUNG

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

Date:     Wed, 19 Aug 87 10:49:21 BST
From:     Nick Higham (Manchester) <[email-masked]>
To:       [email-masked]
Subject:  GAUSS and PC-MATLAB

               Matrix Computations on a PC: GAUSS and PC-MATLAB.
 
In response to the recent request for more contributions to NA Digest I offer 
some thoughts on two interactive matrix computation packages for MSDOS 
machines (i.e. PCs): GAUSS and PC-MATLAB. This is not a comprehensive review, 
but rather brief notes aimed at informing people who work in matrix 
computations about some of the relative merits of these two packages.  
All opinions are entirely my own. 
 
Both packages require the presence of an 80(2)87 numeric co-processor. The
80(2)87 implements IEEE standard floating point arithmetic.  It provides two
precisions: 32 bit single precision (about 7 decimal digits), and 64 bit 
double precision (about 16 digits).  All its internal computations are carried 
out in 80 bit extended precision. 
 
MATLAB should be familiar to readers of NA digest (see, e.g., the first part
of Axel Ruhe's recent note).  As regards PCs it exists in a public domain
version, the original MATLAB (written in Fortran), and in a more recent, much
faster and more extensive version, PC-MATLAB (written in C), which is marketed
by The MathWorks.  MATLAB is also available on SUNs and VAXes, in a version 
called PRO-MATLAB.
 
GAUSS, from Aptech systems, is broadly similar to PC-MATLAB in its aims and 
features, but it is more strongly oriented towards the statistical analysis of 
data, and the manipulation of large sets of data stored on disk. Judging from 
the brochures it seems to be popular with statisticians, social scientists and 
economists.  It exists only in a PC version and was first released in 1984/5. 
 
Both packages are advertised in the July 1987 issue of SIAM News and I refer
you there for further information on prices, etc.
 
Features in common to both packages: Use double precision.  Seem to run the PC
& co-processor at near maximum efficiency (both solve a 90x90 system Ax=b in
under 30 seconds on a PC-AT).  Interactive, and procedure driven modes.
Include main linear system and eigenvalue routines from LINPACK and EISPACK.
Powerful matrix syntax.  Any single matrix is limited to 8192 elements (thus
n<=90 for an nxn matrix) since it must fit into one 64K MSDOS segment.  Can
execute DOS commands from within the program.
 
Contrasts:
           PC-MATLAB                             GAUSS
           ---------                             -----
Intrinsic complex arithmetic.         Real arithmetic (some facilities for
                                      complex by working with real and imag.
                                      parts separately).
 
Full help screens and demo programs.  Neither - rather unfriendly to the
                                      new user.
 
Line editor based, with capability    Full screen editor - roam around the
to recall and edit previous line.     screen at will.  Execute a sequence
                                      of commands contained within any marked
                                      area of the screen.  Recall previous
                                      screen.  Save screen to disk.
 
Main program resides in memory.       Uses disk overlays.
FOR loops.                            No FOR loops - must be simulated using
                                      a DO loop.
Vector elements referenced as X[i].   X[i,1] - must use two subscripts.
 
Access to Hessenberg and Schur        These absent - could be added by linking
decompositions, matrix exponential    in compiled Fortran code, but this not
and square root, and QZ algorithm.    for the feint-hearted!
 
Square systems solved using           Uses specially-written Crout/Cholesky
LINPACK's DGECO/DPOCO.                routines which accumulate inner products
Rectangular Ax=b solved using the     in extended precision.  Crout has two
QR decomposition (DQRDC).             versions: no pivoting & partial
                                      pivoting.  Rectangular Ax=b solved by
                                      forming and solving the normal equations
                                      entirely in extended precision ("better"
                                      than QR if A is well-conditioned!).
 
Fast screen handling.                 Slower screen handling, due to forced
                                      use of ANSI.SYS screen driver.
 
Output format 5 or 15 digits,         Very versatile Fortran-like control
scaled fixed or floating point.       over output format.
 
Control System Toolbox adds new       Various add-on modules available, written
commands for control applications.    in GAUSS programming language.  E.g.
                                      for hi-res graphics (since only three
                                      primitive routines are built in),
                                      unconstrained nonlinear optimisation
                                      (quasi-Newton), nonlinear least squares,
                                      further stats and data handling.
 
Extremely easy to use, comprehensive  On my copy hi-res graphics require a
and impressive graphics.  The one     CGA adaptor, so I haven't tried them.
program supports all the main         I believe other graphics cards are
graphics adaptors.                    supported in the latest version.
 
Both packages include powerful programming languages (compiling to some forms
of intermediate code) with procedures and functions.  Both enable the user to 
to extend or customise the language using procedures.  PC-MATLAB's syntax is 
the more elegant and concise, but GAUSS has more built-in commands, especially 
regarding statistical functions and handling "datasets" on disk.  I find that 
the GAUSS compiler is fussy about syntax and its error messages are often 
extremely unhelpful.  GAUSS offers great flexibility over configuration (how 
memory is partitioned between symbols and variables, which functions are pre-
loaded etc.) but at the price of complexity. 
 
Summary: Both packages are extremely useful aids to research in matrix
computations, for "n <=90". I recommend both: each has some advantages over
the other.  PC-MATLAB is the easier to learn and the more user-friendly, and
would probably be the first choice of most numerical analysts; GAUSS can be
quicker and more convenient for the "power user".
 
(Can anyone offer any comparative comments on PC Fortrans?)
 
Nick Higham                  [email-masked]
Department of Mathematics
University Of Manchester 
Manchester M13 9PL
England

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

Date: Wed, 19 Aug 87 16:47:56 cdt
From: [email-masked]
Apparently-To: [email-masked]
Subject: B. and K. Datta visit UCSD

  We will be spending our sabbatical year at University of California San
Diego (Mathematics Department) starting September 1, 1987 until June 1988.
We will continue to receive our NA e-mail there.
                   Biswa and Karabi Datta

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

Date: Wed, 19 Aug 87 17:57:03 CDT
From: "Douglas N. Arnold" <[email-masked]>
To: [email-masked]
Subject: Chicago Conference Honoring Jim Douglas

                    ***** Final Announcement and Program *****

            For more information write or phone the Conference Secretary,
          Department of Mathematics, University of Chicago, 5734 University
              Avenue, Chicago, Illinois  60637; phone: (312) 702-7100.
          -----------------------------------------------------------------                                        
              ADVANCES IN COMPUTATIONAL MODELLING AND NUMERICAL ANALYSIS              ADVANCES IN COMPUTATIONAL MODELLING AND NUMERICAL ANALYSIS
                                         ---
  A conference in honor of Jim Douglas, Jr. on the occasion of his 60th birthday
                                         ---
                            September 10, 11, and 12, 1987
                                         ---
                                       Kent Hall
                                1020-24 East 58 Street
                               Chicago, Illinois 60637
                                    (312) 702-7100
 
                    +-----------------------------------------------+
                    |     Thursday, September 10, Kent Hall 120     |
                    +-----------------------------------------------+

                       Morning session chairman:  Richard Ewing

 9:30 A.M.  Ivo Babuska                    Finite element methods for elliptic
            University of Maryland         problems with piecewise analytic data

11:00 A.M.  Vidar Thomee                   Numerical solution of parabolic
            Chalmers Institute of Tech.    integro-differential equations

                      Afternoon session chairman:  Richard Falk

 2:00 P.M.  James Bramble                  Some remarks on mixed methods
            Cornell University

 4:00 P.M.  Jean-Claude Nedelec            Homogenization of the problem of eddy
            Ecole Polytechnique, Paris     currents in a transformer core

 6:30 P.M.  Wine and informal buffet at Douglas residence, 5531 S. Kimbark Avenue

                    +-----------------------------------------------+
                    |      Friday, September 10, Kent Hall 107      |
                    +-----------------------------------------------+

                        Morning session chairman:  John Osborn

 9:00 A.M.  Joachim Nitsche                Finite element methods for conformal
            Albert-Ludwigs-U., Freiburg    mappings

10:30 A.M.  Mitchell Luskin                Numerical results for liquid crystals
            University of Minnesota

                     Afternoon session chairman:  Donatella Marini

 1:00 P.M.  Roland Glowinski               Numerical methods for the Hamilton-
            University of Houston          Jacobi  equations

 2:30 P.M.  Mary Wheeler                   Modelling of subsurface transport
            Rice University

 4:00 P.M.  Douglas Arnold                 Recent resultson the Mindlin-Reissner
            University of Maryland         plate equations

 6:00 P.M.  Banquet in honor of Jim Douglas at the Quadrangle Club, 1155 E 57 St.
            Cash bar from 6:00-7:00, dinner at 7:00

                    +-----------------------------------------------+
                    |     Saturday, September 10, Kent Hall 120     |
                    +-----------------------------------------------+

                      Morning session chairman:  Raymond Johnson

 9:00 A.M.  Herb Keller                    To be announced
            CalTech

10:30 A.M.  Craig Douglas                  Recent advances in parallel multigrid
            I.B.M. Watson Research Center

                       Afternoon session chairman:  Paul Saylor

 1:00 P.M.  Franco Brezzi                  To be announced
            Universita di Pavia, Italy

 2:30 P.M.  Jacques-Louis Lions            Exact controllability of distributed
            College de France, Paris       systems. New results. Open problems.

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

Date: Wed, 19 Aug 87 18:24:07 PDT
From: Tony Chan <[email-masked]>
To: [email-masked]
Subject: Domain Decomposition Conference, UCLA, Jan 14-16, 1988.

            SECOND ANNOUNCEMENT AND CALL FOR PAPERS

    2nd INTERNATIONAL SYMPOSIUM ON DOMAIN DECOMPOSITION METHODS

   University of California, Los Angeles, January 14 - 16, 1988.

THEME

Domain Decomposition is a class of methods for solving mathematical physics
problems by decomposing the physical domain into smaller subdomains
and obtaining the solution by solving smaller problems on these subdomains.
The motivation may be : the ability to use different mathematical models
and approximation methods in different subdomains, use of fast direct methods
in subdomains, memory limitations of the computer and suitability for
implementation on parallel computers.  Applications can be found in many
areas of scientific computing and related industrial applications,
such as computational fluid dynamics and structural mechanics.

This symposium is a sequel to the First International Symposium on
Domain Decomposition Methods held in Paris in January, 1987.
The aim is to bring together the leading researchers in this rapidly expanding
and highly interdisciplinary field to survey and review the progress that
has been made since the last symposium.  There will be approximately 25
invited papers and a limited contributed papers/poster session.
In selecting invited and contributed papers, the organizing committee
will try to keep a balance between the mathematical development, associated
algorithms and their implementation on parallel computers, and
industrial applications.

ORGANIZING COMMITTEE

James Bramble (Cornell), 
Tony F. Chan (UCLA), 
Roland Glowinski (Houston/INRIA),
Jacques Periaux (GAMNI/SMAI/AMDBA),
Olof Widlund (NYU).

INFORMATION FOR AUTHORS

Authors who wish to submit a paper should send 3 copies of 
an extended abstract (no longer than
2 pages and include preprints/reports if available) 
to :

Prof. Tony F. Chan, Department of Mathematics, UCLA, 405 Hilgard Ave.,
Los Angeles, CA 90024. (Electronic mail: [email-masked]).

The deadline for submission is November 1, 1987. 
Acceptance will be notified before December 1, 1987.
It is expected that selected papers will be published in a proceedings
about June 1988.
Authors should plan to have a full length paper ready by mid-March 1988.

REGISTRATION

Registration forms, travel and hotel information can be obtained by writing to:

Elain Barth, Dept. of Mathematics, UCLA, 405 Hilgard Av., 
Los Angeles, CA 90024.

Registration fee is US$100, which includes refreshment, abstracts and one 
banquet ticket. Student registration fee is US$50. Extra banquet ticket
is US$25.

RELATED CONFERENCES

The annual AIAA meeting will be held in Reno, Nevada from January 11-14, 1988.
The Third conference on Hypercube Concurrent Computers and Applications
will be held the following week (January 19-20, 1988) in nearby Pasadena.

SPONSOR

Office of Naval Research under an University Research Initiative Grant.

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

Date: Thu, 20 Aug 87 12:24:43 cdt
From: [email-masked] (Danny Sorensen)
To: [email-masked]
Subject: Availability of SCHEDULE package on Netlib

The SCHEDULE package for writing explicitly parallel programs in Fortran
is now available on NETLIB.  The purpose of this package is to provide 
a tool for constructing portable software for parallel computers.  It allows
one to express algorithms with synchronization requirements that are beyond
the capabilities of loop based parallelism normally supported by vendors. 
It also provides the capability of dynamic spawning of processes at 
run time and interfaces well with existing Fortran libraries.  The users 
code will port between the parallel computers that SCHEDULE is running on
without change.  In addition there is a graphics post processing capability
that is useful for performance analysis and debugging.  This trace facility
runs on SUN workstations.

The package is available on the following computers

     SUN
     VAX
     ALLIANT FX/8 
     SEQUENT BALANCE 21000
     ENCORE MULTIMAX
     CRAY-2
     FLEX (experimental)

To get a copy of the code for one of the above machines send e-mail to 
netlib

   mail [email-masked]

In the message body put

     send <machine name> from sched
     send trace from sched
     send uguide from sched

where <machine name> is one of the following

 alliant  balance  cray2  encore  flex sun

trace is the graphics post processor for a SUN workstation
and uguide is the current draft of the users guide.  

Dan Sorensen          and       Jack Dongarra
[email-masked]           [email-masked]

Mathematics and Computer Science Division
Argonne National Laboratory

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End of NA Digest
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