Subject: NA Digest, V. 92, # 26 NA Digest Sunday, July 5, 1992 Volume 92 : Issue 26 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com Today's Topics: Seeking a Temporary Position in Rhode Island Area MasPar Software From the _Mathematical_Enquirer_ Software for Bordered Matrices LAPACK Update Braziliam Symposium on Artificial Intelligence Contents: Journal of Computational and Applied Mathematics Submissions for NA Digest: Mail to na.digest@na-net.ornl.gov. Information about NA-NET: Mail to na.help@na-net.ornl.gov. ------------------------------------------------------- From: Zvika Bar-Deroma Date: Sun, 05 Jul 92 22:28:49 IST Subject: Seeking a Temporary Position in Rhode Island Area I will spend a year starting the coming September in Providence, RI, and I am looking for a position in Providence or in the vicinity. I would like to work in CFD or numerical analysis, as computer professional or as a teaching assistant. My experience includes work in CFD (viscous subsonic), computer work (system management in UNIX, VAX/VMS and work as a consultant) and teaching experience (fluid dynamics and programming). I will send further information upon request. I may be contacted at the following address: Zvi Bar-Deroma Dept. of Aerospace Eng. Technion City Haifa 32000 Israel Fax: +972 4 231848 Phone: +972 4 292706 e-mail: aer7101@technion.technion.ac.il ------------------------------ From: Pamela Burrage Date: Mon, 29 Jun 92 09:56:31 +1000 Subject: MasPar Software At the University of Queensland (Australia) we have a MasPar MP-1, with 4096 processors. On behalf of the other users here, I would like to collate information on any software available for the MasPar (public domain or otherwise). If anyone has such software details, could they please send them to me. Thank you. Pamela Burrage, Centre for Information Technology Research, U of Q. ------------------------------ From: Van Snyder Date: Mon, 29 Jun 92 10:31:06 PDT Subject: From the _Mathematical_Enquirer_ I found the following in rec.humor on the internet news. It was produced by several individuals. I don't deserve any credit. Enjoy. -- Van ASTONISHING NEWS FROM _THE_MATHEMATICAL_ENQUIRER_ : You favourite power series reveals your personality! My life with Moebius: TV shows only one side. Fermat speaks from the grave: "I missed a factor of two -- hope it's been no inconvenience!" Was Ramanujan an ET???? Strange attractors stole my wife! Top psychics predict: Riemann hypothesis, NSF funding, more! Catastrophe in the royal family: Is Lady Di a butterfly or a cusp? Trapped in Klein Bottle, Man Swallows Own Mouth and Lives! Astonishing photos of Ellipse with 3 foci discovered! Chebyshev can't spell own name! I computed cohomology groups for the CIA and KGB! ------------------------------ From: W. Govaerts Date: Tue, 30 Jun 92 09:38 N Subject: Software for Bordered Matrices In many computational problems linear systems with coefficient matrix in block form ( A B ) M = ( ) ( C^T D ) arise naturally. Here A is n by n, B and C are n by m and D is m by m; C^T is the transpose of C. If m is much smaller than n, M is called a bordered matrix. In this case A often has a special structure (symmetric, banded, block banded, sparse...) that is not present in M. This structure of A may make it relatively easy to construct a solver for A. One then wants to use this solver to solve linear systems with M. This can be done by block elimination methods in several ways; unfortunately stability may be lost in passing from a solver for A to a solver for M. This is the case especially if A is ill - conditioned while M is reasonably well- conditioned. (In the computation of bifurcation points in numerical continuation and bifurcation A is often theoretically singular; roundoff and truncation only make A slightly nonsingular). We want to advertize here a collection of Fortran subroutines to help remedy this situation. The code was developed by W. Govaerts (Gent,Belgium) and J. D. Pryce (RMCS,England) and called BEMW (Block Elimination Mixed for Wider Borders). It is a reverse communication code with modest size: less than 16k including an example program, full documentation and 3 BLAS core subroutines. It is available now in Fortran single precision. The calling program has to provide solvers for both A and A^T but the use of the subroutrines requires no reference to the elements of A or of the solution procedure. The matrices B, C, D have to be stored in a specific but natural way. The first (factorization) part of an application of BEMW requires m solves with A and m solves with A^T. The second (solution) part takes as many applications of the solver with A (respectively A^T) as there are right hand side vectors to be solved with M (respectively M^T). (In typical applications solutions with M^T as well as with M are necessary). Theory and numerical examples are given by W. Govaerts (Stable solvers and block elimination for bordered systems, SIAM J. Matrix Anal. Appl. 12 (1991) 469 - 483) and W. Govaerts and J. D. Pryce (Mixed block elimination for linear system with wider borders, to appear in IMA J. numer. anal.). For practical purposes, it is enough to know that we expect that BEMW will solve linear systems with M and M^T in a (backward) stable way provided that the solvers for A and A^T are themselves stable. In particular, systems with a well-conditioned M are solved accurately even if A is arbitrarily ill-conditioned. We had very satisfactory results about this case in numerical continuation and bifurcation problems. People interested in BEMW should send a short note to govaerts@mathanal.rug.ac.be. We shall of course be happy to hear about their experiences. ------------------------------ From: Susan Ostrouchov Date: Thu, 2 Jul 92 16:29:32 -0400 Subject: LAPACK Update SUBJECT: LAPACK HAS HAD ITS FIRST UPDATE ON-LINE DOCUMENTATION AND BUG FIXES!!! We have decided on the following proposed maintenance schedule for LAPACK: LAPACK will be revised through "minor" and "major" updates. The "minor" updates will occur either bimonthly or quarterly and will consist of code and commenting changes. The first such update occurred June 30, 1992. These minor updates will be denoted by a change in the date and version number of an affected routine. The version number will be changed from 1.0 to 1.0a and so on. The "major" updates will occur yearly to introduce new routines and whatever wasn't caught by the "minor" updates. For these "major" updates the date on the affected routine will be changed as well as the version number being incremented from 1.0 to 1.1 and so on. NAG will receive a new tape yearly at the time of each "major" update. Updating the version numbers from 1.0 to 2.0 and so on will be reserved to correspond with new versions of the LAPACK Users' Guide. In other words, a couple of years down the road. The source for LAPACK will be updated on netlib at the time of the "minor" and "major" updates. In addition, via xnetlib, there will be a compressed/tar file of only the most recent changes that you can obtain and simply untar on top of your existing LAPACK directory. The entire package in lapack.tar.Z will always be the most up-to-date, and include all revisions. We are also maintaining ERRATA lists for the LAPACK Users' Guide and the LAPACK source code. These ERRATA lists are contained in the release_notes for LAPACK. This file may be obtained by sending email to netlib@ornl.gov and in the message type: send release_notes from lapack. LAPACK, VERSION 1.0a, June 30, 1992 DETAILS: Our first such "minor" update occurred June 30, 1992. All affected routines have a version number of 1.0a and a date of June 30, 1992. This update encompassed many minor corrections to documentation, argument checking and so on. In addition, a few significant errors have been corrected in certain routines (CHEGST, CHSEQR, SSTEBZ and their double precision equivalents). One routine changed its name (CLANST --> CLANHT) to avoid confusion in notation. And finally, the makefile in LAPACK/TIMING will now do SMALL or LARGE data set timings. By default, typing 'make' will do the SMALL timings, or if you type 'make large' it will do only the LARGE timings. Check the errata lists in the release_notes for more information. Via xnetlib, there is a tar file of changes that you can obtain and simply untar on top of your existing LAPACK directory. The file is called revisions1.0a.tar.Z. The release_notes file contains details of the changes made to specific routines. The entire package available in lapack.tar.Z includes all revisions made in release 1.0a. Additional features introduced with version 1.0a of LAPACK: -- on-line manpages for LAPACK driver and computational routines -- on-line LINPACK and EISPACK to LAPACK equivalence information The manpages are available as a compressed/tar file of troff files and the equivalence program and may be obtained via xnetlib. A README file with instructions is included with the files. If you have any questions/comments please contact us at lapack@cs.utk.edu. Regards, Jack Dongarra Susan Ostrouchov ------------------------------ From: Edson Costa de Barros Carvalho Filho Date: Wed, 1 Jul 92 12:39:26 EST Subject: Braziliam Symposium on Artificial Intelligence NINTH BRAZILIAN SYMPOSIUM ON ARTIFICIAL INTELLIGENCE - SBIA'92 Rio de Janeiro, 5th - 8th October 1992 DEADLINE 31st July 1992 Final Call for Papers The ninth Brazilian Symposium on Artificial Intelligence, SBIA'92, will be held in Rio de Janeiro on October 1992, in conjunction with the congress of the Brazilian Society for Computing Science (SBC). This symposium is a promotion of the SBC and its goal is to communicate the national and international scientific production on artificial intelligence, and to provide an environment to exchange ideias and experiences among professional, researchers, and students. EVENTS: * Technical Sessions * Poster Sessions * Invited Talks * New Product Demonstrations CATEGORIES FOR SUBMISSIONS BUT NOT RESTRICTED TO: Knowledge Acquisition and Representation Philosophy and Artificial Intelligence Expert Systems and Applications Perception and Machine Vision Natural Language Processing Logic and Formal Systems Intelligent Interfaces Neural Networks Reasoning Robotic ADDRESS FOR SUBMISSIONS AND GENERAL INFORMATION: Sociedade Brasileira de Computacao - SBIA'92 Av. Venceslau Bras, 71 fundos casa 27 22290 Rio de Janeiro - RJ BRAZIL Phone (021) 2954846 or (021) 2954442 Fax (021) 5415342 FOR TECHNICAL INFORMATION PLEASE CONTACT: Technical Programme Chairman: Prof. Edson C de Barros Carvalho Filho Universidade Federal de Pernambuco Departamento de Informatica 50739 - Recife - PE BRAZIL Phone (081) 2718430 or (081) 2713052 email: edson@ufpe.di.br or sbia92@di.ufpe.br PROGRAMME COMMITTEE: Gentil Lucena, UNB Guilherme Bittencourt, INPE Marcos Mota Costa, EMBRAPA-UFPE Mario Benevides, UFRJ-COPPE Newton Viera, UFMG Rosa Viccari, UFRGS Tarcisio Pequeno, UFCE ------------------------------ From: G.A. Anastassiou Date: 30 Jun 92 15:28:44 CDT Subject: Contents: Journal of Computational and Applied Mathematics Journal of Computational And Applied Mathematics Applied Analysis and Stochastics Guest Editors: G.A. Anastassiou & S.T. Rachev CONTENTS G.A. Anastassiou and S.T. Rachev Editorial B.C. Arnold Logistic and semi-logistic processes [CAM 1212] J. Boos and H. Tietz Convexity theorems for the circle methods of summability [CAM 1215] M. Bramson and C. Neuhauser A catalytic surface reaction model [CAM 1211] A. Gross and J.B. Robertson Ergodic properties of stationary Poisson sequences [CAM 1210] G. Hinsen Explicit irregular sampling formulas [CAM 1213] S. Jansche and R.L. Stens Best weighted polynomial approximation on the real line; a functional-analytic approach [CAM 1233] P.R. Masani The measure-theoretic aspects of entropy, Part I [CAM 1208] M.I. Taksar Skorohod problems with nonsmooth boundary conditions [CAM 1237] ------------------------------ End of NA Digest ************************** -------