**Today's Topics:**

- Symbolic Manipulators
- Whereabouts of one Bernadette Miara
- Position Wanted
- Conference Honoring Jim Douglas

Posted-From: The MITRE Corp., Bedford, MA

To: na@SCORE.STANFORD.EDU

Date: Fri, 24 Jul 87 09:21:22 EDT

From: James R. Van Zandt <jrv@mitre-bedford.ARPA>

> ... does anyone care to volunteer opinions concerning microcomputer-based

> symbolic manipulation software (such as mu-math)?

>

> Baker Kearfott

> rbk@usl.edu

I've spent some time with muMATH. I think it needs work in three areas:

1. The command language is hard to work with. Control variables

determine whether, for example, expressions are distributed or

factored. Positive values cause distribution while negative values

cause factoring. The different types of expressions (numerical,

sums, others) are each assigned a prime number, and the value

assigned to a variable is the product of the corresponding set of

primes. This is even worse than the usual scheme, of summing the

correct set of powers of 2.

2. Expressions are displayed in a linear format similar to FORTRAN

rather than a 2D format with built-up fractions, etc. However, the

latest Soft Warehouse newsletter had an ad for CALC-87, available

in source code, which is supposed to include this. (source: R.

Freese or D. Stegenga, Dept. of Mathematics, U of Hawaii,

Honolulu HI 96822, $35. Caveat emptor - I haven't tried it.)

3. There are no convenient ways to select a subexpression, perform

some operations on it, and substitute it back. I've made some

progress on this one.

One would expect size limitations on a microcomputer system, and in

fact the documentation includes a fair amount of discussion on space

optimization. However, the documentation (and program, for the most

part) dates from 1983, when 640K machines were less common. (muMATH

can use up to 320K.) I've run out of space only due to programming

errors (infinite recursion).

Unfortunately, I've had no significant experience with other symbolic

manipulation systems, so I can't give many comparisons. However, I

notice that in MATHLAB (a precursor of MACSYMA) you could specify which

variables were more important so that, for example, in a polynomial the

like powers of a given variable would be collected. muMATH doesn't let

you do this.

Has anybody else been working on extending muMATH? Would the na library

accept contributions of muMATH source code?

- Jim Van Zandt

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Date: Fri, 24 Jul 87 09:32:08 MDT

From: Roland Sweet <sweet@boulder.colorado.edu>

To: na@SCORE.STANFORD.EDU

Does anyone know the whereabouts of Bernadette Miara. Several months ago she

sent me a message, but my reply to her via nanet has been returned as undeliv-

erable. I would appreciate any help in determining her address--electronic or

postal. Thanks.

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

Date: Sun, 26 Jul 87 16:18 MST

From: Juan-Carlos Lerman <na.lerman@score.stanford.edu>

To: na@score.stanford.edu

From: JUAN-CARLOS LERMAN <na.lerman@score.stanford.edu>

To: EVERYONE on the NA NETWORK

Re: POSITION WANTED

M.S. (Buenos Aires), Ph.D. (Paris), I am currently looking for a position

in research or/and teaching or/and service.

My expertise is in the field of numerical and computational experiments and

simulations, including computer techniques, numerical analysis, exploratory

statistics, time-series and data analysis. I have published applications to

diverse areas such as geophysics and geochemistry, and physiology.

Recently contributed to the development of new methods to study spacial and

temporal data sequences, of application also to biomedical areas of clinical

importance. This work was supported by a Senior Fellowship award from the NIH

(National Institutes of Health).

This award allowed me to work during several years in a multidisciplinary

field relating mathematics, dynamical systems, computations, physics, biology,

and medicine.

I can provide a curriculum vitae, reviewers comments, publications lists,

and other information by e-mail.

Phones: (602) 795-6534 at home, and (602) 621-4664 at the Applied Math

Program, Univ. of Arizona, Tucson, AZ 85721.

E-mail addresses: na.lerman in the NA NETWORK

and also at: newell1@arizrvax in BITNET

(THESE ARE MULTIUSER ACCOUNTS. PLEASE MENTION MY NAME IN MESSAGE'S HEADINGS.)

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

Date: Tue, 28 Jul 87 20:25:33 CDT

From: "Douglas N. Arnold" <arnold%s1.ima.umn.edu@umn-cs.arpa>

To: NA@score.stanford.edu

***** Second Announcement and registration form *****

ADVANCES IN COMPUTATIONAL MODELLING AND NUMERICAL ANALYSIS

University of Chicago

September 10, 11, and 12, 1987

A conference in honor of Jim Douglas, Jr.

on the occasion of his sixtieth birthday.

The conference will focus on recent advances in techniques of

scientific computation, especially the numerical solution of

differential equations, and their mathematical analysis. The

conference will consist of invited lectures with ample time for

discussion. Lectures will be presented by

Douglas Arnold Jacques-Louis Lions

Ivo Babuska Mitchell Luskin

James Bramble Jean-Claude Nedelec

Franco Brezzi Joachim Nitsche

Craig Douglas Vidar Thomee

Roland Glowinski Mary Wheeler

Herbert Keller

REGISTRATION: Conference registration is $10 if received by

August 15. If paid after August 15 or at the conference,

registration is $15. A banquet in honor of Professor Douglas

will be held on Friday, September 11, at the Quadrangle Club.

ACCOMODATIONS: Rooms are available at the Hyde Park Hilton at a

special conference rate of $65 for a single or double room. To

receive these rates your reservations must be received by the

conference secretary by August 15. Reservation requests

received thereafter will be subject to room availability and

will not benefit from the reduced conference rate.

CONFERENCE SUPPORT: The conference is supported by the National

Science Foundation, the Air Force Office of Scientific Research,

and the Office of Naval Research.

To register use the form below. Make checks payable to the

University of Chicago. For more information write:

Conference Secretary

Department of Mathematics

University of Chicago

5734 Univerisity Avenue

Chicago, Illinois 60637

phone: (312) 702-7100

--------- detach here and return to the Conference Secretary --------

Name: ___________________________________________ Phone: ____________

Address: ___________________________________________________________

___________________________________________________________

___________________________________________________________

_____ Yes, I plan to attend. Enclosed please find my registration

fee of $10 ($15 after August 15).

_____ I will attend the banquet. An additional $20 is enclosed.

----- Please reserve a single room for me. I attend to arrive on

______________ and depart on ______________.

_____ Please reserve a double room for me and a companion. We intend

to arrive on ______________ and depart on ______________.

_____ Please reserve a double room for me and _______________________

who will also attend the conference. We intend to arrive on

______________ and depart on ______________.

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

End of NA Digest

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