**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 <BLAFAPWY%UIAMVS.BITNET@wiscvm.wisc.edu>

To: NA@SCORE.STANFORD.EDU

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 na.potra@score.stanford.edu

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: NA@SCORE.STANFORD.EDU

FROM: K1401AE%DM0LRZ01.BITNET@wiscvm.wisc.edu

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) <na.higham@score.stanford.edu>

To: na@score.stanford.edu

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.

B

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 na.higham@score.stanford.edu

Department of Mathematics

University Of Manchester

Manchester M13 9PL

England

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

Date: Wed, 19 Aug 87 16:47:56 cdt

From: niuvax!dattab@anl-mcs.ARPA

Apparently-To: na@SCORE.STANFORD.EDU

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" <arnold%s1.ima.umn.edu@umn-cs.cs.umn.edu>

To: NA@score.stanford.edu

***** 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 <chan@MATH.UCLA.EDU>

To: na.dis@score.stanford.edu

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: chan@math.ucla.edu).

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: sorensen@anl-mcs.ARPA (Danny Sorensen)

To: na.dis@score.stanford.edu

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 netlib@anl-mcs.arpa

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

sorensen@anl-mcs.arpa dongarra@anl-mcs.arpa

Mathematics and Computer Science Division

Argonne National Laboratory

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End of NA Digest

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