krj@utcsri.UUCP (07/29/87)
NA Digest Tuesday, July 28, 1987 Volume 87 : Issue 63 This weeks Editor: Cleve Moler 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 Subject: Symbolic Manipulators 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 ------------------------------ Date: Fri, 24 Jul 87 09:32:08 MDT From: Roland Sweet <sweet@boulder.colorado.edu> To: na@SCORE.STANFORD.EDU Subject: Whereabouts of one Bernadette Miara 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> Subject: Position Wanted 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 Subject: Conference Honoring Jim Douglas ***** 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 ************************** -------