From nacomb@surfer.EPM.ORNL.GOV Sun Mar 8 21:38:03 1992 Return-Path: Received: from surfer.EPM.ORNL.GOV by CS.UTK.EDU with SMTP (5.61++/2.8s-UTK) id AA26432; Sun, 8 Mar 92 21:37:56 -0500 Received: by surfer.EPM.ORNL.GOV (5.61/1.34) id AA18511; Sun, 8 Mar 92 21:37:40 -0500 Date: Sun, 8 Mar 92 21:37:40 -0500 From: nacomb@surfer.EPM.ORNL.GOV (NA-NET) Message-Id: <9203090237.AA18511@surfer.EPM.ORNL.GOV> Subject: NA Digest, V. 92, # 10 Apparently-To: dongarra@cs.utk.edu Status: R NA Digest Sunday, March 8, 1992 Volume 92 : Issue 10 Today's Editor: Cleve Moler The MathWorks, Inc. moler@mathworks.com 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 na.digest@na-net.ornl.gov. Information about NA-NET: Mail to na.help@na-net.ornl.gov. ------------------------------------------------------- From: Jack Dongarra 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 netlib@ornl.gov, 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 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 netlib@ornl.gov. 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 xnetlib@cs.utk.edu. Jack Dongarra Tom Rowan Reed Wade ------------------------------ From: Robert G. Voigt 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: rvoigt@nsf.gov 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 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 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 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: reichel@mcs.kent.edu phone: (216) 672-2547 A. Ruttan e-mail: ruttan@mcs.kent.edu phone: (216) 672-2073 R.S. Varga e-mail: varga@mcs.kent.edu phone: (216) 672-2145 Institute for Computational Mathematics Kent State University Kent, OH 44242 ------------------------------ From: stanly@crunch.unm.edu (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, stanly@math.unm.edu Elaine Kant, kant@slcs.slb.com Richard Keller, keller@ptolemy.arc.nasa.gov or American Association for Artificial Intelligence 445 Burgess Drive, Menlo Park, CA 94025 (415) 328-3123 fss@aaai.org Stan Steinberg ------------------------------ From: Venkat Sastry 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: sastry@uk.ac.cran.rmcs. ------------------------------ From: Tom Manteuffel 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 cm-info@teuf.denver.colorado.edu 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 cmcim92@copper.denver.colorado.edu. 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 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: householder93@math.ucla.edu ------------------------------ From: Max Gunzburger 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: gunzburger@vtcc1.bitnet or gunzburger@vtcc1.cc.vt.edu ------------------------------ From: Maria Morandi Cecchi 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: adtmora@ipduniv.bitnet 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 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 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: na.baltzer@na-net.ornl.gov ------------------------------ End of NA Digest ************************** -------