Subject: NA Digest, V. 92, # 10

From: [email-masked] (NA-NET)
Date: Sun, 8 Mar 92 21:37:40 -0500

NA Digest   Sunday, March 8, 1992   Volume 92 : Issue 10
 
Today's Editor:
 
    Cleve Moler
    The MathWorks, Inc.
    [email-masked]
 
Today's Topics:

    LAPACK is Now Available
    Second Release of XNETLIB
    New Address for Bob Voight
    Butcher's Birthday Problem for Gene
    Looking for E-Mail Addresses
    High Performance Computing and Communications Initiative
    Conference at Kent State on Numerical Linear Algebra
    Intelligent Scientific Computation at AAAI Meeting
    One Day MATLAB Short Course in UK
    Copper Mountain Progran and Information
    Householder Symposium XII
    Appalachian Numerical Analysis Day
    Conference in Italy on Innovative Methods in Numerical Analysis
    Report on the Tenth Parallel Circus
    Contents: Numerical Algorithms

Submissions for NA Digest: 
    Mail to [email-masked].
 
Information about NA-NET:
    Mail to [email-masked].
 
-------------------------------------------------------

From: Jack Dongarra <[email-masked]>
Date: Fri, 6 Mar 92 12:36:44 -0500
Subject: LAPACK is Now Available

            ( L   A    P    A    C    K )
            ( L  -A    P   -A    C   -K )
            ( L   A    P    A   -C   -K )
            ( L  -A    P   -A   -C    K )
            ( L   A   -P   -A    C    K )
            ( L  -A   -P    A    C   -K )

LAPACK is a transportable library of Fortran 77 subroutines for
solving the most common problems in numerical linear algebra: systems
of linear equations, linear least squares problems, eigenvalue problems,
and singular value problems. It has been designed to be efficient
on a wide range of modern high-performance computers.

LAPACK is intended to be the successor to LINPACK and EISPACK.
It extends the functionality of these packages by including driver 
routines, iterative refinement and error bounds for linear systems, the 
capability for finding selected eigenvalues and invariant subspaces, and 
condition estimation for the eigenproblem.  LAPACK improves on the accuracy 
of standard algorithms for linear systems, for finding singular values and 
singular vectors of bidiagonal matrices, and for finding eigenvalues and 
eigenvectors of tridiagonal matrices.  The algorithms and software in the 
package have been restructured to achieve high efficiency on vector processors, 
high-performance ``superscalar'' workstations, and shared memory 
multiprocessors. In addition to the LAPACK routines, comprehensive 
testing and timing suite is provided along with the LAPACK software.

The LAPACK Users' Guide will be available from SIAM in or around May, 1992.
The Users' Guide gives an informal introduction to the design of the algorithms
and software, summarizes the contents of the package, describes conventions
used in the software and documentation, and includes complete specifications
for calling the routines. 

The LAPACK routines are available from netlib for users who require only 
selected pieces of the package.
For a description of the contents of LAPACK, send email to
[email-masked], and in the mail message type: send index from lapack.
A set of working notes are available from netlib as well and details
can be found in the index to LAPACK.

The complete LAPACK package can be obtained on magnetic media from NAG for a
nominal handling charge. For further details, contact NAG at one of these
addresses: 

NAG Inc                       NAG Ltd              NAG GmbH
1400 Opus Place               Wilkinson House      Schleissheimerstrasse 5
Suite 200                     Jordan Hill Road     W-8046 Garching bei Munchen
Downers Grove, IL 60515-5702  Oxford OX2 8DR       Germany 
USA                           England
Tel: +1 708 971 2337          Tel: +44 865 511245  Tel: +49 89 3207395
Fax: +1 708 971 2706          Fax: +44 865 310139  Fax: +49 89 3207396

LAPACK has been funded in part by NSF, DOE, and DARPA, with
developmental support from NAG Ltd., Cray Research, and many friends
and colleagues around the world.

Ed Anderson, Zhao-jun Bai, Chris Bischof, Jim Demmel, Jack Dongarra, 
Jeremy Du Croz, Anne Greenbaum, Sven Hammarling, Alan McKenney, 
Susan Ostrouchov, and Danny Sorensen

            (           l    l    l    l )
            (           a   -a    a   -a )
      1/4 * ( p    p             -p   -p )
            ( a   -a             -a    a )
            ( c    c   -c   -c           )
            ( k   -k   -k    k           )

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

From: Jack Dongarra <[email-masked]>
Date: Fri, 6 Mar 92 17:21:23 -0500
Subject: Second Release of XNETLIB

We have a second release version of XNETLIB.

XNETLIB is a new version of NETLIB recently developed at the University
of Tennessee and Oak Ridge National Laboratory.  Unlike NETLIB, which
uses electronic mail to process requests for mathematical software,
XNETLIB uses an X Window graphical user interface and a socket-based
connection between the user's machine and the XNETLIB server machine to
process software requests.

To receive a copy of XNETLIB send the message "send xnetlib.shar from
xnetlib" to [email-masked].

When you receive the shar file, remove the mail header, save it to a
file, type 'sh filename' and follow the instructions in the README
file.

Send comments to [email-masked].

Jack Dongarra
Tom Rowan
Reed Wade

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

From: Robert G. Voigt <[email-masked]>
Date: Mon, 2 Mar 92 17:20:46 -0500
Subject: New Address for Bob Voight

             Position Change

Effective immediately my address is

   Robert G. Voigt
   Room 417
   National Science Foundation
   1800 G Street, N.W.
   Washington, DC
   20550

   Phone: (202) 357-7727
   email: [email-masked]

I am Program Manager for the New Technologies program in the Division
of Advanced Scientific Computing.  I look forward to continued 
interaction with the scientific computing community.

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

From: Walter Gander <[email-masked]>
Date: Tue, 3 Mar 92 11:22:55 +0100
Subject: Butcher's Birthday Problem for Gene

There were some requests for the problem that John Butcher asked me to
give as birthday present to Gene on occasion of his 60th birthday. 
Here it is.

   - Walter Gander

\centerline{\bf A birthday problem for Gene Golub}
\bigskip
\centerline{\bf composed by John Butcher}
\bigskip

Let $n$ be a positive integer and $t$ a real number.  Define
$a_0$, $a_1$, $a_2$, \dots, $a_n$, and $b_0$, $b_1$, $b_2$, \dots, $b_n$, by 
$$\halign{\qquad$#$\hfil&$#$\hfil\qquad&$#$\hfil&$#$\hfil\cr
a_0 & = 1,     &  b_0 & = 1,\cr
a_1 & = t-1,   &  b_1 & = 1-t,\cr
  a_k & = {(-1)^{k-1}\over k+1}L^\prime_{k+1}((k+1)t),\quad k\ge2,
& b_k & = {(-1)^{k-1}\over k}tL^\prime_{k}((k-1)t),\quad k\ge2, \cr
}
$$
where
$$L_n(t) = 1-{n\choose 1}t + {1\over 2!}{n\choose2}t^2-\cdots+(-1)^n{1\over n!}t^n$$ 
denotes a Laguerre polynomial.
\bigskip

\noindent{\bf Problem 1.}  Prove that
$$
  a_0 b_n + a_1 b_{n-1} + a_2 b_{n-2} + \cdots + a_n b_0 = 0.
$$
\bigskip

\noindent{\bf Problem 2.}  Find an application to numerical ordinary
differential equations.

\bye

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

From: Mustafa Pinar <[email-masked]<
Date: Thu, 5 Mar 92 12:04:43 EST
Subject: Looking for E-Mail Addresses

I am trying to get in touch with the following people
as soon as possible through e-mail. I would appreciate it
if I could get their e-mail addresses from the NANET users
or if someone could direct me to a directory. The names are:

Susana Gomez, Instituto Investigaciones en Mathematicas
Applicadas y en Sistemas-Universidad Nacional Autonoma
de Mexico, Mexico.

Gianni DiPillo, Universita di Roma " La Sapienza", Italy.

Luigi Grippo , same address as DiPillo.

Mei-Qin Chen, The Citadel. 

Thank you very much.

And also thanks to all users who responded to my earlier
paper request from a Polish Journal.

Mustafa Pinar

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

From: Judith Sunley <[email-masked]>
Date: Thu, 5 Mar 92 11:28:07 PST
Subject: High Performance Computing and Communications Initiative

NOTICE RE: HPCC (High Performance Computing and Communications) Initiative,
and Mathematical Scientists

It has come to our attention that there are some misunderstandings  with
regard to NSF activities under the HPCC rubric.

It is essential that all be aware and understand that the Grand Challenge
Application Groups activity, of which you have been informed recently, is
NOT the only avenue for members of the Mathematical Sciences community to
participate in the HPCC initiative.  

Individual and group research activities which fit within the guidelines of
HPCC can apply directly to the most appropriate programs within NSF,
including in particular any of the programs in the Division of Mathematical
Sciences, as well as programs in the Computer and Information Sciences
Directorate at NSF, and the recently-announced Computational Approaches to
Real Materials activity.  There is no deadline nor pre-proposal letter of
intent required for such activities.

Program directors may be contacted directly, by phone or e-mail, to discuss
ideas and plans for proposals.

      Judith Sunley, Director, Division of Mathematical Sciences, NSF

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

From: Lothar Reichel <[email-masked]>
Date: Wed, 4 Mar 92 23:56:24 -0500
Subject: Conference at Kent State on Numerical Linear Algebra

                     KENT CONFERENCE   
                            on
                 NUMERICAL LINEAR ALGEBRA
                           and
                  SCIENTIFIC COMPUTATION
                            at
                  Kent State University
                            at
                        Kent, Ohio
                            on
                     March 13-14, 1992

FRIDAY, MARCH 13, 9am - 5:30pm

 M.H. Gutknecht, ETH
 Changing the norm in conjugate gradient type algorithms.

 Y. Saad, University of Minnesota
 Multi-color parallel preconditioners.

 W.J. Layton, University of Pittsburg
 Massively parallel iterative methods for highly nonsymmetric 
 problems.

 R.W. Freund, RIACS, NASA
 Formally biorthogonal polynomials and a look-ahead Levinson 
 algorithm for general Toeplitz systems.

 N.M. Nachtigal, RIACS, NASA
 An implementation of the QMR method based on coupled two-term 
 recurrences.

 G. Starke, University of Karlruhe
 Alternating direction preconditioning for nonsymmetric systems 
 of linear equations.

 D. Calvetti, Stevens Institute of Technology
 An adaptive Chebyshev iterative method for nonsymmetric linear 
 systems based on modified moments.

 V. Simoncini, University of Illinois at Urbana-Champaign
 A memory-conserving hybrid method for solving linear systems 
 with multiple right hand sides.

 M. Eiermann, University of Karlsruhe
 Error estimates for semi-iterative methods.

SATURDAY, MARCH 14, 9am - 5:30pm

 G.W. Stewart, University of Maryland
 Updatable, rank-revealing matrix decomposition.

 P. Van Dooren, University of Illinois at Urbana-Champaign:
 Generalized QR and SVD decompositions. Algorithms and 
 applications.

 V. Fernando, University of California at Berkeley
 Accurate singular values and the qd algorithm.

 W.B. Gragg, Naval Postgraduate School
 Algorithms for updating QRP' factorizations.

 J.D. Gardiner, Ohio State University
 Stability of interval matrices.

 R. Nabben, University of Bielefeld
 Numerical methods for nonsymmetric block structured matrices 
 arising in the solution of Euler equations.

 M. Hanke, University of Karlruhe
 Iterative methods for discrete ill-posed problems.

 X.-C. Cai, University of Kentucky
 Domain decomposition preconditioned iterative methods for 
 nonsymmetric problems.

 G.S. Ammar, Northern Illinois University
 Updating and downdating Szego polynomials.

For questions about the conference, please, contact the organizers:

L. Reichel   e-mail: [email-masked]   phone: (216) 672-2547
A. Ruttan    e-mail: [email-masked]    phone: (216) 672-2073
R.S. Varga   e-mail: [email-masked]     phone: (216) 672-2145

Institute for Computational Mathematics
Kent State University
Kent, OH 44242

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

From: [email-masked] (Stanly Steinberg)
Date: Mon, 2 Mar 92 08:25:44 MST
Subject: Intelligent Scientific Computation at AAAI Meeting

I am helping organize a symposium,

        Intelligent Scientific Computation,

at the AAAI Fall Symposium Series, October 23, 24, & 25, 1992, Cambridge,
Massachusetts.  For more information contact:

    Stan Steinberg, [email-masked]
    Elaine Kant, [email-masked]
    Richard Keller, [email-masked]
or
    American Association for Artificial Intelligence
    445 Burgess Drive, Menlo Park, CA  94025
    (415) 328-3123
    [email-masked]

    Stan Steinberg

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

From: Venkat Sastry <[email-masked]>
Date: Wed, 4 Mar 92 15:23 GMT
Subject: One Day MATLAB Short Course in UK

                            One day Course
                   MATLAB: a tutorial introduction

27 May 1992
Applied and Computational Mathematics Group
Royal Military College of Science.

The course is specifically  designed  for  scientists,  engineers  and
lecturers  who  either  use  routine  numerical/matrix calculations in
their specific application  area  or  teach  the  subject  at  various
levels.  No specialist knowledge of programming or computer science is
required, but participants are expected to  have  basic  knowledge  of
computing and to be educated to HNC or degree level.

The course provides hands-on experience of  the  MATLAB  package,  and
will  be  followed  by  an in-depth presentation of case studies which
deal with specialist topics from  Signal  Processing,  Control  System
Design, Numerical Computations, Splines and Optimization.  Most of the
afternoon is devoted to tutorials and the participants will have ample
opportunity to work on a specialist topic of their choice.

The course lectures will be given by the teaching and  research  staff
of the Applied and Computational Mathematics Group under the direction
of Dr. Venkat V.S.S. Sastry.

For more information please write to Mrs.  P.  M.   Moore, Applied and
Computational  Mathematics  Group, RMCS, Shrivenham, Swindon,  Wilts.,
SN6 8LA  or Tel:  (0793) 785317   or   e-mail: [email-masked].

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

From: Tom Manteuffel <[email-masked]>
Date: Tue, 3 Mar 92 14:53:10 -0700
Subject: Copper Mountain Progran and Information

                     Copper Mountain Conference
                                on
                         Iterative Methods

                          April 9-14, 1992

Preliminary Program:

The Conference Program is now available. There are 115 talks scheduled
in two parallel sessions. The talks begin Friday, April 10 at 8:00 am.
The Program will be mailed to speakers and those who register along with 
registration materials. It is also available by email. Any message to the 
address [email-masked] will result in the return of the 
program along with general information and registration details. If you 
should experience any difficulties or require a personalized response 
please send a message to [email-masked].

Lodging:

Lodging is always the most difficult aspect of the meeting because it is not
within our control. Lodging can be arranged by calling Copper Mountain Resort
at 800-458-8386 or 303-968-2882. At this time there are over 40 hotel rooms
and 20 one bedroom condos still available from the block of rooms reserved
for our conference. Please mention the name of the conference. Another source 
of lodging at Copper Mountain is the Resort Association. They handle
the booking of a large assortment of private condos within the resort. 
Their number is 303-968-6477 (ask for Marie at Extension 17).

Local Transportation:

Limousine service to Copper Mountain from Stapleton Airport is  available
through  Resort  Express (800-334-7433). They offer a group rate
of $22 each way. You may make reservations directly with them.  Please
mention the name of the conference.
 
Tutorial Program:

The Program for the Tutorial on Polynomial Iterative Methods to be held
April 7-8 in Denver is also available. It will attached to the information
accompanying the Conference Program.

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

From: Tony Chan <[email-masked]>
Date: Wed, 4 Mar 92 18:16:02 -0800
Subject: Householder Symposium XII

                   THE HOUSEHOLDER SYMPOSIUM XII
                   MEETING ON NUMERICAL ALGEBRA

     The Householder Symposium XII on numerical algebra will be held 
during the week of June 13-18, 1993 at the UCLA Conference Center, Lake 
Arrowhead, California, about a 2 hour drive from Los Angeles.  This 
meeting is the twelveth in a series, previously called the Gatlinburg 
Symposia.  It has been agreed to rename all subsequent Gatlinburg Symposia 
to honor Alston S. Householder, one of the pioneers in Numerical Linear 
Algebra and organizer of the first four Gatlinburg meetings.  The meeting 
is an international conference of experts in the field of Numerical 
Algebra.  The format of the meeting is a sequence of invited papers during 
the day and special workshops organized by the participants in the 
evening.  There is no formal program, but traditionally a few topics are 
emphasized.  

     The meeting is being organized by the Householder committee, in 
cooperation with the SIAM Activity Group on Linear Algebra.  The local
organizers are Tony F. Chan of UCLA and Gene Golub of Stanford University.
The venue is a first class rustic alpine resort with modern facilities.
The room charge will include room and board.  It is hoped that we will
have the whole conference center to ourselves.

     The traditional format of the Householder Symposia requires that the 
attendence be limited.  The organizing committee invites all qualified 
persons to apply to attend.  For planning purposes, please let us know 
of your intention to attend as soon as possible, preferably before
December 1, 1992. We'll maintain a mailing list and keep you informed.
The actual application should consist of a vita and an extended abstract
(about two pages) of a paper you would present if invited to speak.
The latter will be used by the committee in planning the program.
Material should be sent to us before February 1, 1993 to:

                             Householder 93              
                           c/o Babette Dalton
                       Department of Mathematics
                   University of California, Los Angeles
                           405 Hilgard Avenue
                    Los Angeles, California  90024-1555

                    e-mail: [email-masked]

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

From: Max Gunzburger <[email-masked]>
Date: Thu,  5 Mar 92 14:55 EST
Subject: Appalachian Numerical Analysis Day

APPALACHIAN NUMERICAL ANALYSIS DAY

April 4, 1992 - 8:30-5:00

Virginia Tech - McBryde 126

An informal get-together of numerical analysts andcomputational
scientists in the Appalachian region will occur on the above date
and room. The day will be organized as follows. We will convene at
8:30 A.M. at which time all will introduce themselves. Talks will
take place from 9:00-12:00 and from 1:30-5:00. Anyone wishing to
give a talk will put their name into a hat; then, names will be
drawn to determine the order of the talks. The length of the talks
will be determined by the number of persons volunteering to talk.
The time from 12:00-1:30 will be devoted to lunch.

A block of rooms has been reserved (for participants in this event)
at the Best Western Red Lion Inn of Blacksburg (703-552-7770) for
the night of Friday, April 3; the rate is $45.00 per night per room
(up to four people). These rooms will be held until March 21; please
refer to "Virginia Tech Center for Applied Math" when making
reservations. This motel is within 5 minutes of the Virginia Tech
campus. Rooms are also reserved for the night of Saturday, April 4
for those who wish to drive back home on Sunday.

To get to the campus area from Interstate 81, get off at exit 118 and
follow US460 West to Blacksburg. Make sure you take both the
Christiansburg and Blacksburg bypasses (these are US 460) and not
the business routes. Get off US460 at the Prices Fork Road
interchange. The Red Lion Inn is in the direction of Prices Fork,
while McBryde is in the downtown direction. For those coming via
Interstate 77, get off at exit 9 and take US460 East to the Prices
Fork Road interchange; thereafter, follow the above directions.

A map (showing the locations of the Red Lion Inn, McBryde,
and parking areas) is available upon request.

We would appreciate it if recipients of this message wouldpublicize
this event to their colleagues, students, etc.

Further details may be obtained from:
      Max Gunzburger
      Interdisciplinary Center for Applied Mathematics
      Virginia Tech
      Blacksburg, VA 24061-0531
      703-231-7667
      Fax: 703-231-7079
      e-mail: [email-masked]
         or   [email-masked]

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

From: Maria Morandi Cecchi <[email-masked]>
Date: Sat, 7 Mar 1992 10:44 N
Subject: Conference in Italy on Innovative Methods in Numerical Analysis

                    INTERNATIONAL CONFERENCE ON
               INNOVATIVE METHODS IN NUMERICAL ANALYSIS

                       BRESSANONE - ITALIA 
                      September 7-11, 1992

The Scientific Committee

C. Brezinski (Lille) 
F. Brezzi (Pavia) 
I. Galligani (Bologna) 
G.H. Golub (Stanford) 
M. Morandi Cecchi (Padova)  
R. Temam (Paris)

 Accommodation and conferences will take place at Bressanone, a summer 
extension of Padova University, located into the Alps near Bolzano.

 Bressanone can be reached by train through Verona and by car through the 
Brennero highway. The closest international airports are Milano airports 
of Malpensa and Linate (also Verona has a small airport).

 The aim of this conference is to gather mathematicians of new numerical 
techniques of several developments in the field of dynamical systems related 
to non linear problems.
 All the aspects of the subject are intended to be covered. 
 The proceedings will be published.
 Some invited lectures are planned.

 Participants are invited to arrive on Sunday September 6 and to leave on 
Saturday September 12.

 The registration fees (including the social events and a copy of the
proceedings) are 400,000 liras (180,000 liras for accompanying persons) and 
they must be sent (in liras and free of charge for us) to

account #     31001/T 
beneficiary:  CISE (Centro Informatica Studi Editoriali)
              Via Prati 19, Padova 
bank:         Banca Antoniana 
              Sede - Via VIII febbraio -- Padova, ITALY

 Deadline for registration, sending the abstract (1 page) and a proof of 
payment is
                           JUNE 10, 1992

 An additional fee of 50,000 liras will be charged for late registration.

 The complete papers should be brought at the congress.

 If you intend to participate and give a talk, please write as soon as 
possible to

Maria Morandi Cecchi 
Dipartimento di Matematica Pura ed Applicata 
Universita` degli Studi di Padova 
Via Belzoni 7 
35131 Padova -- Italy 
e-mail: [email-masked] 

 A second announcement, with details about the accommodation and the 
proceedings, will be sent in July.

The Organizing Committee
E. Centenaro, S. De Marchi, L. Paccagnella, M. Morandi Cecchi,
M. Redivo Zaglia.

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

From: Faisal Saied <[email-masked]>
Date: Fri, 6 Mar 92 15:09:56 -0600
Subject: Report on the Tenth Parallel Circus

   The Tenth Parallel Circus was held at Oak Ridge on October 25-26.
This series of meetings continues a tradition that was started at Yale
in 1986. The Parallel Circus has evolved into a forum that allows
researchers in parallel computing to present and discuss new
developments in an ``interactive'' environment that is often not
possible at the larger conferences. An attractive feature of the
Parallel Circus is the deliberate attempt to include as many graduate
students in the list of speakers as possible.

   The meeting was organized by Gene Golub, and the Math/CS group 
at Oak Ridge. In particular, Michael Leuze and Esmond Ng worked
hard to ensure its success. Gene, along with Apostolos Gerasoulis
and Ahmed Sameh, arranged for NSF support for a number of graduate
students to attend, which was well appreciated. The Parallel Circus 
well attended, with 32 speakers and over 100 participants. In fact 
the large turnout necessitated a change of venue from the hotel to the 
American Museum of Science and Energy at Oak Ridge.

   The topics ranged over most areas of parallel numerical computing.
Talks on direct parallel methods included Susan Ostrouchov,  who
described her contribution to LAPACK, the BLAS and the LACS, the
(basic) Linear Algebra Communications Subroutines. Susan presented
performance statistics for dense triangular solves on the Intel
Touchstone (Delta) machine. Mark Jones from Argonne spoke about using
parallel graph coloring heuristics to construct efficient parallel
preconditioners for large sparse matrices and described performance on
the Delta as well. This approach can avoid the severe problems that
point ILU preconditioners face on massively parallel computers. Tim
Davis from the University of Florida described joint work with Ian
Duff on unsymmetric pattern multifrontal methods for sparse Gaussian
elimination, that go beyond using the pattern of (A + A-transp). The
goal is to detect certain patterns in the sparse matrix and use dense
matrix kernels on the appropriate blocks. Lie Wang discussed the
spectral nested dissection ordering for sparse matrices, using results
from Alex Pothen and Horst Simon that use the second eigenvector to
construct separators for the underlying graph. For parallel
efficiency, separators that lead to higher fill-in may be acceptable
provided the elimination tree is balanced and not to deep. Sesh
Vinugopal from Rutgers addressed another issue that arises in parallel
sparse GE, namely how the computations in the factor phase can be
efficiently scheduled on a parallel computer. In particular, Sesh
described how a DAG of data dependencies between blocks could be
constructed, given the symbolic factorization of the sparse matrix. Mo
Mu from Rice also discussed scheduling for unstructured problems
arising from PDEs, and how ideas from domain decomposition could be
used for enhancing parallelism. Jianping Zhu talked about solving
least squares problems using regularization (A-trans * A + alpha * I)
x = A-trans * b on the iPSC/860, with a hybrid approach that switched
between Householder and Givens transformations. Gene used the
reference to Householder to remark on Householder's affiliation with
the Oak Ridge National Lab.

   Yan-Ming (Mark) Chang from Yale spoke about block preconditioners for
very large sparse matrices, in particular on the use of block diagonal
preconditioners. Using an experimental extension of PCGPAK for
parallel computers, Mark discussed the performance of such
preconditioners with inexact solves, in conjunction with CG and GMRES
on various hypercubes. Other `iterative'' talks included two GMRES
related topics: Dan Hu described joint work with Lothar Reichel,
on using GMRES-like methods for the Sylvester equation, AX - XB = C.
Applying the Arnoldi process, results in a smaller Sylvester equation
that can be solved more economically. Gene Wachspress, who was among the
attendees, pointed out that the Sylvester equations arise in certain 
control problems. Daniela Calvetti discussed a variant of GMRES that
replaces the usual monomial basis by a Newton basis using Leja points.
Yi-ling Chiang described how good convex hull estimates could be 
obtained for the Chebyshev method by considering (A + \mu * I), and 
constructing the Manteufel ellipses for the shifted matrix. 

   Jesse Barlow presented error bounds for Cuppen's divide and conquer
method for tridiagonal matrices that showed that this parallel
algorithm achieved accuracy comparable to the QR method for the
eigenvalues. Cal Ribbens from Virginia Tech gave an entertaining talk
on using Cuppen's method for the generalized eigenvalue problem. The
Schroedinger equation discretized by a HODIE method was cited as one
source of such problems. Results from the Sequent were given.
Deflation turns out to involve a trade-off: the total work can be
reduced, in return for sacrificing load balance. Mike Berry from the
University of Tennessee at Knoxville talked about joint work with Gene
Golub on sparse SVD computations for very large problems. These algorithms,
which use ideas like block Lanczos, subspace iteration and modified
moments, are implemented in SVDPack that Mike has written.

   A number of talks dealt with parallel algorithms for partial
differential equations. Pat Worley spoke about parallelizing across
time, in contrast to the more common approach of parallelizing the
linear algebra problems that arise at each time step in traditional
schemes. Waveform relaxation is an important idea in this context, and
Pat discussed recent work that uses multigrid ideas within waveform
relaxation. Another interesting idea presented was the use of cyclic
reduction to solve bidiagonal systems that arise when certain
multistep methods are parallelized in time. Tad Janik described a
parallel p-version of the (mixed) finite element method on the Sequent
using tensor product basis functions. Tad commented that he had more
experience with the Finite Element Circus, than the Parallel Circus.
John van Rosendale talked about robust parallel multigrid methods for
CFD problems in 3D. He discussed a scheme that used a 3D Chebyshev
grid, with plane relaxation and semi-coarsening. Bernard Bialecki
described orthogonal spline collocation methods for separable elliptic
problems, which result in matrices that are amenable to domain
decomposition techniques. Kumar Mahinthakumar spoke about his work on
modeling groundwater contamination on the CM2, where the linear
systems were solved by PCG. Kumar observed that for their problem on the
CM2, diagonal scaling outperformed other preconditioners like ILU, and
attributed this to the very high performance of the matrix vector
products on the CM, relative to ILU. Abdul Khaliq, describing joint
work with Dave Voss, spoke about parallel parabolic methods that 
use partial fractions. Partial fractions are an attractive way of 
increasing parallelism and have been used by Gallopoulos and Saad, 
and Sweet. Khaliq and Voss have extended this approach to handle problems 
with discontinuities between the initial values and boundary
values, by constructing L-stable methods with simple partial fraction
expansions. Nikos Chrisochoides of Purdue talked on mapping pde computations
onto distributed memory machines.  Nikos, who is contributing to Parallel
Ellpack, spoke of extending the idea of decompositions based on
geometry to decompositions based on phenomena and gave a glimpse of
the X-window style user interface being developed for Ellpack. Thaib
Taha has developed parallel solvers for some higher Korteweg-de Vries
equations, which have strong nonlinearities. The matrices arising in
this method are essentially four-diagonal, and the linear solves are
parallelized by a partitioning method that requires the solution of a
reduced system.  Steve Cote described implementations of FFT-based
fast Poisson solvers on the 128 processor iPSC/860 at Oak Ridge. For
large enough problems (255^3), he was able to get over 200 Megaflops
in FORTRAN. Steve pointed out that these results need to be seen in
the context of the rather disappointing performance of the compiler
for the i860, which restricts the 128 node machine to a peak
performance of around 500 Mflops, for compiled code. Yue Zhuge, from
Stony Brook spoke on parallel methods based on Lax-Wendroff, for
hyperbolic problems with interfaces.

   There were two talks that served to remind the audience that parallel
computing is not the exclusive domain of ``number crunchers''. Albert 
Choy talked about parallel heuristic search methods, which have potential 
applications in robot path planning, and Hongwei Du discussed parallel 
algorithms for finding the center of a polytope.

   In addition to talks related to parallel algorithms, several
speakers addressed the software problem. Michael Frumkin described a
library of systolic algorithms he has developed at Scripps for a Unix
environment.  Apostolos Gerasoulis unveiled the PYRROS system that
handles task scheduling for message passing architectures, that grew
out of the older Schedule system. PYRROS pays particular attention to
the important issue of granularity and this capability was illustrated
by examples involving the Gauss-Jordan algorithm. Future plans include
applying PYRROS to sparse matrix computations. Adam Beguelin described
work on HeNCE, the Heterogeneous Network Computing Environment being
developed at Oak Ridge, that builds upon the well known PVM (Parallel
Virtual Machine) system. PVM is available through netlib (``send index
from pvm''), HeNCE will be made available in the near future. HeNCE
allows the user to specify parallelism in her/his program graphically.
Doreen Chang described her work evaluating interactive tools for
parallelizing codes on multiprocessor Crays, such as FORGE and fpp
from Cray. The codes used in the benchmarks were drawn from the
Livermore loops, NAS applications and the Perfect benchmarks. Terry
Pratt from Virginia raised the audience's hopes about the prospects
for parallelizing ``dusty decks'', but warned that these hopes should
not get too high.

   Jack Dongarra gave a sneak preview of xnetlib at the beginning of the 
conference and in a separate talk, described the present state of LAPACK, 
the Linear Algebra package that combines and substantially enhances 
LINPACK and EISPACK.

   The Chinese banquet has become a tradition at the Parallel Circus,
and the Tenth was no exception. We look forward to the next Parallel 
Circus to be held in Minneapolis, April 24--25.

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

From: J. C> Baltzer <[email-masked]>
Date: Thu Mar  5 14:23:52 1992
Subject: Contents: Numerical Algorithms

Contents
Numerical Algorithms
Volume 2, no. 1

 S.  Dubuc and A.  Malik
 Convex hull of powers of a complex number, trinomial equations and the
 Farey sequence

 M.-J. Lai
 Fortran subroutines for B-nets of box splines on three- and four-directional
 meshes

 C. Rabut
 Elementary m-harmonic cardinal B-splines

 C. Rabut: High level m-harmonic cardinal B-splines

 A.  Bultheel, P.  Gonzalez-Vera, E. Hendriksen and O. Njastad
 The computation of orthogonal rational functions and their interpolating
 properties.

Please submit your papers to one of the Editors of NUMERICAL ALGORITHMS.
Volumes 2 and 3 to be published in 1992.  Requests for sample copies and
orders are to be sent to J.C. Baltzer AG, Scientific Publishing,
fax: +41-61-692 42 62, e-mail: [email-masked]

------------------------------
 
End of NA Digest
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