**Today's Topics:**

- Updated NA Net Mailing List
- Examples of "Pseudo-eigenvalues"
- Changes of Address for Youcef Saad
- Textbook Recommendation Sought
- New Book on Linear Control Design
- First Issue of SIAM Journal on Optimization
- Contents: SIAM J. Control and Optimization
- ICASE Meeting on Scalable Multiprocessors
- ICS'91 Call for Papers
- 5th Copper Mountain Conference on Multigrid Methods
- Multigrid Short Course
- Is There a "Public Domain MATLAB?"

From: The NA Net <na@na-net.stanford.edu>

Date: Sun Sep 30 20:08:03 PDT 1990

Mark Kent has put a lot of effort into bringing the NA Net mailing

list up to date. It now has 1558 entries. The list is used both

for this NA Net News Digest and for the NA Net e-mail forwarding

service. The later is accessed by sending mail to

na.lastname@na-net.stanford.edu

If there is an unambiguous match to 'lastname' in the mailing list,

the mail will automatically be forwarded. If there is more than one

match, you will be sent a message with the possible messages,

together with the initials which must be prepended to distinguish

among them. If there is no match, you will be sent a message saying so.

Thanks, Mark, for updating the list.

-- Cleve

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

From: Nick Trefethen <nick@hydra.maths.unsw.OZ.AU>

Date: Fri, 21 Sep 90 22:31:47 +1000

Dear colleagues:

I am in the process of writing a review of applications in numerical

analysis of the theory of what I like to call "pseudo-eigenvalues" of

non-normal matrices. If A is a matrix and eps is a positive

real number, then a complex number z is defined to be an

"eps-pseudo-eigenvalue of A " if it satisfies either of the

following equivalent conditions:

(i) z is an eigenvalue of A+E for some perturbation

matrix E with norm(E) <= eps ; or

(ii) The resolvent satisfies norm(inv(zI-A)) >= 1/eps .

Many topics seem to be illuminated by this notion, such as the

power-boundedness of families of matrices, the convergence of matrix

iterations, the behavior of certain adaptive algorithms, and the

stability of discretizations of p.d.e.'s.

Can any of you help me by pointing out references in this area

that I may have missed? For example, the definitions above were

used by Varah in 1979; have other authors used them too, perhaps earlier?

A plot of numerically computed pseudo-spectra (i.e., level curves

of the norm of the resolvent) appears in a 1987 paper of Demmel;

have any other such plots been published? More generally, I am

always on the lookout for interesting examples of matrices whose

eigenvalues are highly sensitive to perturbations, and have found

matrices of this kind in the literature due to Kahan, Ruhe, and Higham,

among others. Are there other good examples I may be unaware of?

I would be grateful for any comments or references on these topics.

Nick Trefethen

School of Mathematics, University of New South Wales

P.O. Box 1, Kensington, NSW 2033 Australia

nick@hydra.maths.unsw.oz.au

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

From: Youcef Saad <saad@riacs.edu>

Date: Sat, 29 Sep 90 14:18:05 PDT

Colleagues:

From Oct. 1 to Oct 30, my address will be

Youcef Saad, National Tsing Hua University

Institute of Applied Math.,

Hsinchu, Taiwan 30043, Republic of China.

Starting Nov. 1st 1990, my permanent address will be:

Youcef Saad

Computer Science Dept.

University of Minnesota

4-192 EE/CSci Building

200 Union Street S.E.

Minneapolis, MN 55455-0159

Phone: (612) 624-7804 (Office)

(612) 625-4002 (CS dept)

(612) 624-9802 (Office at the

Minnesota Supercomp. Inst.)

e-mail: saad@cs.umn.edu, na.saad@na-net.stanford.edu

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

From: Martin Berzins <martin@dcs.leeds.ac.uk>

Date: Mon, 24 Sep 90 08:15:40 BST

Introductory texts in mathematical software & scientific computation.

Starting in January 1991, I have to teach a 20 lecture + practicals

course to provide an introduction to numerical methods with a strong

slant towards mathematical software and scientific computation.

Does anyone know of a suitable text, preferably with examples in

Pascal? The best I've managed to do so far are two out-of-print books

- An Introduction to Numerical Computation in Pascal, Dew and James,

Macmillan and

-Numerical Methods A Software Approach, R.L. Johnston, Wiley.

Both are out of print now.

The book by Ortega and Poole on differential equations is very

good and has some

of the material but is too advanced for first-year students.

Any suggestions?

-- Martin Berzins (na.berzins)

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

From: Stephen Boyd <boyd@ISL.Stanford.EDU>

Date: Mon, 24 Sep 90 08:58:35 MDT

New book available

Linear Controller Design: Limits of Performance

by Stephen Boyd and Craig Barratt (Stanford EE Dept.)

is now available.

The main topic of the book is closed-loop design and the computation

of performance limits using convexity. The book introduces a standard

framework for the control design problem and describes many practical

design specifications in this framework. It is shown that many of these

specifications are closed-loop convex; the corresponding control design

problems can therefore be solved using the convex optimization algorithms

described in the latter part of the book.

Some special points of interest for NA people:

* The whole point of the book is to apply more numerical computing to

the problem of controller design than is commonly done. This is done

by casting many controller design problems as infinite-dimensional

nondifferentiable convex optimization problems.

* Two standalone chapters cover norms of signals and systems,

and their computation.

* Two standalone chapters cover convex analysis and nondifferentiable

convex optimization, emphasizing ellipsoid and cutting-plane methods.

Many numerical examples illustrate the typical behavior of these

algorithms.

* Over 27000 lines of matlab source were written to generate the numerical

examples and 216 plots and figures. To the authors' knowledge, the extent

of the numerical computation in this book is unprecedented in a book on

control systems.

* Title: Linear Controller Design: Limits of Performance

(428 pages, 216 figures, bibliography, index).

* Publisher: Prentice-Hall Inc.

* ISBN: 0-13-538687-X, Title Code: 538-686.

-- Stephen Boyd & Craig Barratt

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

From: SIAM Publications Department <SIAMPUBS@wharton.upenn.edu>

Date: Wed, 26 Sep 90 11:01 EDT

SIAM JOURNAL ON OPTIMIZATION

February 1991 Volume 1, Number 1

CONTENTS

William C. Davidon

Variable Metric Method for Minimization

Roger Fletcher

A New Variational Result for Quasi-Newton Formulae

Kurt M. Anstreicher

On the Performance of Karmarkar's Algorithm over a Sequence of Iterations

Guangye Li

Successive Element Correction Algorithms for Sparse Unconstrained Optimization

V. Jeyakumar

Composite Nonsmooth Programming with Gateaux Differentiability

John R. Engels and Hector J. Martinez

Local and Superlinear Convergence for Partially Known Quasi-Newton Methods

Jong-Shi Pang, Shih-Ping Han, and Narayan Rangaraj

Minimization of Locally Lipschitzian Functions

Y. Dai, G. van der Laan, A. J. J. Talman, and Y. Yamamoto

A Simplicial Algorithm for the Nonlinear Stationary Point Problem on an

Unbounded Polyhedron

Jiu Ding and Tien-Yien Li

A Polynomial-Time Predictor-Corrector Algorithm for a Class of Linear

Complementarity Problems

C. T. Kelley and Ekkehard W. Sachs

A New Proof of Superlinear Convergence for Broyden's Method in Hilbert Space

Jorge J. More and Gerardo Toraldo

On the Solution of Large Quadratic Programming Problems with Bound Constraints

O. L. Mangasarian

Convergence of Iterates of an Inexact Matrix Splitting Algorithm for the

Symmetric Monotone Linear Complementarity Problem

Virginia Torczon

On the Convergence of the Multidirectional Search Algorithm

EDITORIAL BOARD

Kurt M. Austreicher

Francisco O. Barahona

Dimitri P. Bertsekas

Frank H. Clarke

Andrew R. Conn

John E. Dennis

Donald Goldfarb

Clovis Gonzaga

C. T. Kelley

Masakazu Kojima

O. L. Mangasarian

Jose Mario Martinez

Jorge J. More

George Nemhauser

Jorge Nocedal

Michael L. Overton

R. T. Rockafellar

Roger W. H. Sargent

Michael A. Saunders

Robert B. Schnabel

Alexander Schrijver

Richard A. Tapia

Eva Tardos

PH. L. Toint

Layne T. Watson

Roger J.B. Wets

Margaret H. Wright

Yinyu Ye

Stavros A. Zenios

Francesco Zirilli

Jochem Zowe

For additional information, please contact

SIAM

3600 University City Science Center

Philadelphia, PA 19104-2688

telephone: 215-382-9800

fax: 215-386-7999

e-mail: siam@wharton.upenn.edu.

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

From: SIAM Publications Department <SIAMPUBS@wharton.upenn.edu>

Date: Fri, 28 Sep 90 14:30 EDT

Table of Contents

SIAM J. Control and Optimization

Vol. 29, No. 1, January 1991

J. S. Gibson and A. Adamian

Approximation Theory for Linear-Quadratic-Gaussian Control of

Flexible Structures

B. Charlet, J. Levine, and R. Marino

Sufficient Conditions for Dynamic State Feedback Linearization

Manlio Gaudioso and Maria Flavia Monaco

Quadratic Approximations in Convex Nondifferential Optimization

D. S. Gilliam, B. A. Mair, and C. F. Martin

An Inverse Convolution Method for Regular Parabolic Equations

P. Acquistapace, F. Flandoli, and B. Terreni

Initial Boundary Value Problems and Optimal Control for

Nonautonomous Parabolic Systems

Paul Tseng

Applications of a Splitting Algorithm to Decomposition in Convex

Programming and Variational Inequalities

R. H. Kwong

On the Linear Quadratic Gaussian Problem with Correlated Noise

and its Relation to Minimum Variance Control

U. Faigle and W. Kearn

Note on the Convergence of Simulated Annealing Algorithms

A. A. Stoorvogel

The Singular H Control of Problem with Dynamic Measurement Feedback

Henry Hermes

Asymptotically Stabilizing Feedback Controls and the Nonlinear

Regulator Problem

Vilmos Komornik

Rapid Boundary Stabilization of the Wave Equation

G. da Prato, A. J. Pritchard, and J. Zabcyzk

On Minimum Energy Problems

Michael Pedersen

Pseudodifferential Perturbations and Stabilization of Distributed

Parameter Systems: Dirichlet Control Problems

For additional information regarding the SIAM J. Control and Optimization,

please contact

Vickie Kearn, Publisher

SIAM

3600 University City Science Center

Philadelphia, PA 19104-2688

telephone: 215-382-9800

fax: 215-386-7999

e-mail: siampubs@wharton.upenn.edu

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

From: Joel Saltz <saltz-joel@CS.YALE.EDU>

Date: Mon, 24 Sep 90 00:48:51 EDT

PRELIMINARY AGENDA

UNSTRUCTURED SCIENTIFIC COMPUTATION ON SCALABLE MULTIPROCESSORS

Ramada Inn, Kill Devil Hills, NC

October 29-31, 1990

Sponsored by ICASE

Monday, October 29, 1990

Manuel Salas, NASA Langley Research Center

An Assessment of Unstructured-Grid Methods for the

Analysis of Aircraft Fields

Harold Trease, Los Alamos National Laboratory

The Free-Lagrange Method on the Connection Machine

Steven Hammond, Robert Schreiber, NASA Ames Research Center

Mapping Unstructured Grid Problems to the Connection Machine

Steven G. Kratzer, Supercomputing Research Center

Unstructured Sparse QR Factorization on SIMD Computers

Kapil K. Mathur, Thinking Machines Corporation

Data Parallel Algorithms for the Finite Element Method

Joel Saltz, ICASE, NASA Langley Research Center

Runtime Compilation for Multiprocessors

Ting-Fook Ngai, Stephen Lundstrom and Michael Flynn,Stanford University

Run-Time Scheduling of Unstructured Scientific

Computation on Scalable Multiprocessors

Charles Koelbel, Rice University, Piyush Mehrotra, ICASE,

Compiler Support for Unstructured Scientific Computations

Steve Roy, Princeton University

Parallelization of Adaptive Fast Multipole Algorithms

Jack B. Dennis, Dataflow Computer Corporation

Compiling Irregular Codes for Data Parallel Execution

Tuesday, October 30, 1990

Roy Williams, California Institute of Technology

Parallel Load Balancing for Parallel Unstructured Meshes

Geoffrey Fox, Syracuse University

Parallel Software and Algorithmic Issues for Fast Nbody Solvers

John A. Board, Jr., James F. Leathrum, Jr., Duke University

Mapping the Fast Multipole Algorithm onto MIMD Systems

Shahid Bokhari, University of Engineering & Technology, Lahore

On-line Parallel Binary Dissection

Rainald Lohner, The George Washington University,

Jose Camberos, Marshal Merriam, NASA Ames Research Center

Parallel Unstructured Grid Generation

David Keyes, Yale University and ICASE,

Adaptive Refinement in Domain Decomposition Methods

Calvin J. Ribbens, Virginia Polytechnic Institute and State University

A Moving Mesh Scheme for Dynamically Adaptive Domain Decomposition

R. Henderson, G. Karniadakis, Princeton University

Hybrid Spectral Element-Finite Difference Techniques on

Multiprocessing Environments

Sukumar R. Chakravarthy, Sampath Palaniswamy

Rockwell International Science Center

Some Aspects of Single-Zone Structured-Grid CFD For Hypercube

MIMD Computer

Charbel Farhat, University of Colorado at Boulder

L. Fezoui, S. Lanteri, INRIA, France

Unstructured Compressible Flow Computations on the Connection Machine

Wednesday, October 31, 1990

David Nicol, The College of William and Mary

Algorithmic Issues in Mapping Workload

Kirk R. Pruhs, Taieb F. Znati, Rami G. Melhem, University of Pittsburg

Dynamic Mapping of Adaptive Finite Element Computations onto

Linear Arrays

Sharon L. Smith and Robert B. Schnabel, University of Colorado at Boulder

Centralized and Distributed Dynamic Scheduling for Adaptive,

Parallel Algorithms

William Celmaster, BBN Advanced Computers Inc.

Random-Access Bandwidth and Grid-Based Algorithms on Massively

Parallel Computers

Mo Mu, John Rice, Purdue University

Performance of PDE Sparse Solvers on Hypercubes

Edoardo S. Biagioni, Jan F. Prins, University of North Carolina

Scan Directed Load Balancing for Highly-Parallel Mesh-Connected

Computers

Please contact Emily Todd by October 8 1990 if you are interested

in attending.

E-Mail emily@icase.edu

US Mail

Emily Todd

MS 132C ICASE

NASA Langley Research Center

Hampton VA

23665

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

From: Ruediger Esser <ZDV003%DJUKFA11.BITNET@Forsythe.Stanford.EDU>

Date: Mon, 24 Sep 90 08:52:29 MES

CALL FOR PAPERS

1991 ACM International Conference on

Supercomputing

June 17-21, Cologne, Germany

Conference Co-Chairmen

Edward S. Davidson, University of Michigan, Ann Arbor, USA

Friedel Hossfeld, Research Center Juelich (KFA), Germany

Program Director

Yoichi Muraoka, Waseda University, Tokyo, Japan

Program Committee

EUROPE AND AFRICA NORTH AND SOUTH AMERICA JAPAN AND FAR EAST

U. Trottenberg (Chair) E. Houstis (Chair) T. Yuba (Chair)

L.M. Delves D. Bailey T. Hoshino

I. Duff F. Darema Y. Kanada

W. Giloi D. DeGroot H. Kashiwagi

J.R. Gurd G. Fox N. Koike

G. Hoffmann E. Gallopoulos S. Nagashima

W. Jalby D. Gannon H. Tanaka

A. Lichnewski M. Heath Y. Tanakura

P. Mueller-Stoy J. McGraw H. Terada

T. Papatheodorou P. Messina K. Toda

P. Sguazzero C. Polychronopoulos

H. Wijshoff J. Rice

H. Zima

The fifth International Conference on Supercomputing is soliciting papers

on significant new research results in the development and use of super-

computer systems. Contributions should emphasize the novel aspects of the

work being reported and should discuss their implications for future

supercomputer development. Papers are welcome on topics including the

following areas:

ARCHITECTURAL DESIGN OF SUPERCOMPUTER SYSTEMS

SOFTWARE SYSTEMS SUPPORT FOR SUPERCOMPUTING

APPLICATIONS OF SUPERCOMPUTING

SUPERCOMPUTING ALGORITHMS AND PERFORMANCE ANALYSIS

Submissions

Authors are invited to send five copies of the full manuscript in English

to the program chairman of their region. Their addresses are:

EUROPE AND AFRICA NORTH AND SOUTH AMERICA JAPAN AND FAR EAST

Ulrich Trottenberg Elias Houstis Toshitugu Yuba

GMD/F1 Dept. Computer Science ETL 1-1-4 Umesono

Schloss Birlinghoven Purdue University Tukuba, Ibaraki

D-5205 Sankt Augustin W. Lafayette, IN 47907 305 Japan

Germany USA

The deadline for submissions is DECEMBER 1, 1990. Authors will be

notified of acceptance by February 20, 1991. Final, camera-ready versions

of accepted submissions will be due by March 20, 1991. The Conference

Proceedings will be published by ACM.

SPONSORS: ACM-SIGARCH in association with AICA, BCS-PPG, CSRD, CTI, CWI,

GI, GMD, INRIA, IPSJ, KFA, SBMAC, and SIAM-SIAGS.

For further details, please contact: Ruediger Esser

KFA-ZAM

D-5170 Juelich, Germany

Phone: +49-2461-61-6588

Fax: +49-2461-61-6656

E-mail: zdv003@djukfa11.bitnet

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

From: Steve McCormick <smccormi@copper.Denver.Colorado.EDU>

Date: Fri, 28 Sep 90 07:54:40 -0600

*** Announcement and Call for Papers ***

5th COPPER MOUNTAIN CONFERENCE

on

MULTIGRID METHODS

Copper Mountain, Colorado

March 31-April 5, 1991

Organized by

University of Colorado at Denver

Front Range Scientific Computations, Inc.

Society for Industrial and Applied Mathematics

Sponsored by

U.S. Air Force Office of Scientific Research

National Science Foundation

IBM

Special Features

Multigrid Circus

Student Paper Competition

Code/Algorithm Bake-Off

Chairmen: Tom Manteuffel & Steve McCormick,

University of Colorado at Denver

Program Chairman: Jan Mandel, University of Colorado at Denver

Program Committee: Joel Dendy, Los Alamos National Laboratory

Craig Douglas, IBM

Guy Lonsdale, Gesellschaft f. Math. u. Datenverarbeitung

Seymour Parter, University of Wisconsin

Joseph Pasciak, Brookhaven National Laboratory

John Ruge, University of Colorado at Denver

Klaus Stueben, Gesellschaft f. Math. u. Datenverarbeitung

James Thomas, NASA Langley

Pieter Wesseling, Delft University

Workshop Chairman: Paul Frederickson, RIACS

This conference traditionally provides a forum for interaction

among basic researchers and practitioners. To promote this, morning

and evening seminar sessions will be held and afternoons will be open

for informal workshops, discussions, and special sessions. Anyone

interested in organizing such a session should contact one of the

chairmen.

The conference will be held at the Copper Mountain Resort, about

75 miles west of Denver. Deluxe condominium accommodations and

adjacent meeting rooms are in the Village Square Lodge at the base of

the Copper Mountain F lift.

PAPERS: Please send title, short abstract, mailing address, phone

number, and e-mail address (if available) BY DECEMBER 1, 1990 to:

Division of Extended Studies

University of Colorado at Denver

Campus Box 164

P.O.Box 173364

Denver, CO 80217-3364, USA

Complete manuscripts for inclusion in the preliminary conference

proceedings will be due MARCH 1, 1991. Selected papers will be

refereed, with authors' consent, for publication in a special

issue of the SIAM Journal on Numerical Analysis.

REGISTRATION: The conference fee ($195 for SIAM members and $215 for

non-members by March 1, $235 and $260 thereafter, $45 any time for

students) should be paid with registration directly to the above

address for the Division of Extended Studies. Please contact one of

the conference chairmen for necessary forms. Conference fee includes

preliminary proceedings, a reception, coffee breaks, and a banquet.

MULTIGRID CIRCUS: Inspired by the finite element circus, we are

including a circus for informal lectures and presentation of late-

breaking research results. Anyone who attends the conference is

welcome to lecture during these sessions, which are tenatively

planned for late afternoon on the first four days.

STUDENT PAPER COMPETITION: Travel assistance will be awarded to a few

students who submit papers that we judge to be the best research papers.

Deadline for submission of student papers is JANUARY 1, 1991. Please

submit your paper with a brief statement of your background (institution,

advisor, expected graduation date) to the Division of Extended Studies

at the above address. Clearly mark it "Student Paper Competition."

MULTIGRID CODE/ALGORITHM BAKE-OFF: Entrants must submit ONE test problem that

has not already been submitted (Poisson's equation on a cube is already taken,

sorry) with a code to generate the matrices, initial guesses, and right-hand

sides in a known language (no copyright notices, please). This will be

distributed to all involved. You will be responsible for timing your own

program on some machine(s). You must also be willing to time other

participants codes on your machine(s). You are not obligated to debug other

people's codes, however. Scalar, superscalar, vector, parallel, and

combination machines are welcome. Craig Douglas will oversee this mess, and

will edit a joint paper with the participants. For more information, and the

real rules, send e-mail to douglas-craig@cs.yale.edu or bells@yktvmv.bitnet.

Deadline for entering is JANUARY 1, 1991.

LODGING should be reserved directly with the Copper Mountain Resort

by calling 1-800-458-8386 in the USA outside of Colorado, 1-800-332-3828

in Colorado, and 303-968-2882 overseas. (FAX: 303-968-2711.) The rates are

$70 for a lodge room (one or two queen beds) and $142 for a two-bedroom

condominium. Limousine and bus service is available from Stapleton

International Airport in Denver. Detailed information is available

on registration forms.

SHORT COURSE: The conference will be preceeded by a week-long multigrid

short course in Denver, March 25-29, 1991. For more information, please

contact:

Chaoqun Liu

Computational Math Group, Campus Box 170

University of Colorado at Denver

1200 Larimer Street

Denver, CO 80204

(303) 556-4807

e-mail: cliu@copper.colorado.edu

FOR REGISTRATION FORMS/FURTHER INFORMATION:

Tom Manteuffel or Steve McCormick

Computational Math Group, Campus Box 170

University of Colorado at Denver

1200 Larimer Street

Denver, CO 80204

(303)556-4807

e-mail: tmanteuf@copper.colorado.edu

smccormi@copper.colorado.edu

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

From: Steve McCormick <smccormi@copper.Denver.Colorado.EDU>

Date: Fri, 28 Sep 90 07:55:48 -0600

*** MULTIGRID SHORT COURSE ***

*** Information & Schedule ***

University of Colorado at Denver

March 25-29, 1991

Principal Lecturer: Achi Brandt

Supporting Lecturers: John Adams, William Briggs, Chaoqun Liu,

Steve McCormick, John Ruge

Shortcourse Chairman: Chaoqun Liu

Purpose: To provide an understanding of the principles and

procedures for multilevel methods, especially for partial

differential equations, including new multilevel approaches

in computational fluid dynamics.

Registration Fee: $500 (regular), $150 (student). Includes books

and other course materials, refreshments, and

computer lab access.

Topics:

. Basic tutorial

. Advanced methods for PDE's (including

multigrid procedures for general systems, nonlinearity,

ellipticity/nonellipticity, time dependence, inverse

problems, indefiniteness, discontinuities, singularities,

performance prediction/analysis, constrained optimization)

. Adaptive techniques (MLAT, FAC)

. Algebraic methods (AMG)

. Computational fluid dynamics (including finite volume element

methods, high Reynolds number flow, steady and unsteady

Navier-Stokes equations, Steady and unsteady Euler equations,

flow transition, and two-phase porous flow)

. Introduction to non-PDE multilevel techniques (including

integral and integro-differential equations, fast

dense matrix multiplication, many-body interactions,

Direct solvers, large determinants, global discrete

highly-nonlinear optimization, and multilevel Monte Carlo

in statistical physics)

Emphasis will be placed on concepts and basic principles, illustrated by

concrete examples and results. Certain codes will be made available to

participants for laboratory experimentation during and after the short

course. Adjustments will be made to the schedule based upon the expressed

interests of the participants.

For Registration and Further Information, Please Contact:

Chaoqun Liu

Computational Mathematics Group

University of Colorado at Denver

1200 Larimer Street, Campus Box 170

Telephone: (303) 556-4807 or (303) 556-4886

e-mail: cliu@copper.colorado.edu

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

From: Cleve Moler <moler@mathworks.com>

Date: Sun Sep 30 20:55:07 PDT 1990

Is There a "Public Domain" MATLAB?

>From time to time, I see references to, or get requests for, the

"public domain" version of MATLAB. As the original author of

MATLAB, and one of the founders of The MathWorks, I would like

to explain how I regard "public domain" MATLAB.

There are two versions of MATLAB. I wrote the first, which we now

refer to as "classic" MATLAB, over the period from 1977 to 1984,

while I was on the faculty at the University of New Mexico. It is

an interactive matrix laboratory, written in Fortran, which uses

some of the subroutines from LINPACK and EISPACK. I distributed

a few hundred copies of the source code, usually charging a

small service charge, and including a letter requesting that the

code not be redistributed. I never used the term "public domain".

The second version, written in C by Steve Bangert and John Little,

is the basis for a family of products from The MathWorks, Inc.,

a company which Bangert, Little and I founded in 1985. These

products are called PC-MATLAB, Mac-MATLAB, Pro-MATLAB, etc.

I obviously recommend that anyone interested in using MATLAB

acquire the MathWorks version appropriate for his or her machine.

In addition to my commercial interest, I believe the MathWorks

versions are preferable scientifically, educationally, and, in the

long run, economically. The MathWorks versions:

* Are faster in execution,

* Have much better storage management,

* Include powerful graphics,

* Are extensible and programmable,

* Can be expanded with sophisticated "toolboxes",

* Are supported by scientific software professionals.

The only feature of classic MATLAB that is not present in modern

MATLAB is the "chop" function which allows the simulation of

shorter precision arithmetic. It is an interesting curiosity,

but it is no substitute for roundoff error analysis and it makes

execution very slow, even when it isn't used.

I know of several serious bugs in classic MATLAB, particularly

in logical and looping operations, but I don't intend to fix them.

In fact, there have been no fixes made to the code since about 1982.

I stopped distributing any copies myself 4 or 5 years ago.

The number of computers for which MathWorks MATLAB is not available

is declining as old machines are retired and new machine versions

are announced.

A few other commercial systems, for example SCT's CTRL-C,

are based on classic MATLAB. That's OK. CTRL-C, was done with

my permission and it helped establish MATLAB in control and

systems engineering. Now the company is a worthy competitor.

I realize that classic MATLAB is available on a few bulletin boards

and through some "freeware" services. In some cases, unauthorized

statements about public domain software are included. I have

regarded this as a mixed blessing. It certainly gives the MATLAB

approach to computing valuable exposure, but I am afraid that some

users of classic MATLAB do not realize how inferior it is to the

MathWorks products.

In summary, here is my position:

* There is no such thing as "public domain" MATLAB.

* I no longer distribute "classic" MATLAB.

* The code and documentation of classic MATLAB cannot

be used for commercial purposes without my permission.

* I would appreciate it if anybody making a copy of

classic MATLAB for personal or educational use

would include this statement with it.

-- Cleve Moler

moler@mathworks.com, or,

na.moler@na-net.stanford.edu

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

End of NA Digest

**************************

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