NA Digest Sunday, May 28, 1989 Volume 89 : Issue 21 Today's Editor: Cleve Moler Today's Topics: Hotels for the ODE meeting in London Seeking Block Toeplitz Solver Help With NAMELIST Under Microsoft Fortran Stability of Negative Norm Projectors Fellowship at Sandia National Laboratories Parallelizing the Simplex Method Eigenvalues of Diagonally Perturbed Matrices Average-case Rounding Analysis Sparse QR Factorization Forming a MATLAB Users Group FAX Numbers ------------------------------------------------------- From: Iain Duff Date: Fri, 19 May 89 10:20:41 CDT Subject: Hotels for the ODE meeting in London Ordinary Differential Equation Conference.. London ... July 1989. Several people have asked for information on hotels in the vicinity of Imperial College. Limited accommodation is available for spouses in the college although no children under the age of 16 will be accommodated. The conference office referenced below is that of Imperial College and the telephone number for further information, bookings, etc. is at the end of the message. HOTEL LIST The hotels listed below, all within walking distance of Imperial College, are bookable through the Conference Office. The rates indicated are rates offered to the Conference Office and should you book direct with the hotel you will probably be charged the normal tariff rate, which will be higher. All rates were current on 1st April and so might possibly be slightly higher. Although VAT is always included in the price, for your information it still stands at 15%. All hotels have bars and restaurants. All prices are in pounds. ELIZABETTA HOTEL This is a purpose built hotel situated on the Cromwell Road - all rates are inclusive of Service, VAT and Continental Breakfast. Single room with bath - 34.00 Double room with bath - 50.00 ENTERPRISE HOTEL Situated on Hogart Road, this hotel is a Victorian terrace conversion - all rates are inclusive of Service, VAT and Continental Breakfast. Single room with bath - 36.00 Double room with bath - 49.00 CRANLEY GARDENS HOTEL** I have not visited so I do not know what it is like - all prices are inclusive of Service, VAT and Continental Breakfast. Single room with bath - 40.00 Double room with bath - 53.00 KENSINGTON INN HOTEL Situated on the Cromwell Road, this hotel is a Victorian terrace conversion - all prices are inclusive of Service, VAT and Continental Breakfast. Single room with bath - 44.00 Double room with bath - 60.00 PRINCE HOTEL Situated on Sumner Place, this hotel is a Victorian terrace conversion - all prices are inclusive of Service, VAT and English Breakfast. Single room with shower - 45.00 Double room with bath - 60.00 EDEN PLAZA HOTEL This hotel is situated on the Cromwell Road and is closest to Imperial College - all prices are inclusive of Service, VAT and English Breakfast. Single room with bath - 47.00 Double room with bath - 54.00 VANDERBILT HOTEL Situated on Cromwell Road, this hotel is a Victorian terrace conversion - all prices are inclusive of Service, VAT and Continental Breakfast. Single room with bath - 57.00 Double room with bath - 76.00 ONSLOW HOTEL This hotel situated on Queen`s Gate is a Victorian terrace conversion - all prices are inclusive of Service and VAT. Single room with bath - 64.75 Double room with bath - 84.15 ALEXANDER HOTEL Situated on Sumner Place, this hotel is a Victorian terrace conversion - all rates are inclusive of Service, VAT and English Breakfast. Single room with bath - 65.00 Double room with bath - 80 00 REGENCY HOTEL Situated on Queen`s Gate, this hotel is a Victorian terrace conversion - all rates are inclusive of Service and VAT. Single room with bath - 71.10 Double room with bath - 84.60 To make a reservation please contact Miss Di Pullar-MacMillan on +44-1-589-5111 extension 3182. ------------------------------ From: P. Flatau Date: 21 May 1989 16:49:53 EST Subject: Seeking Block Toeplitz Solver I am looking for the BLOCK-Toeplitz solver Tx=b, where T - BLOCK Toeplitz; with many b-vectors. I would prefere FORTRAN, MATLAB, or C implementation. I am aware about the TOEPLITZ package available from NETLIB (routine TGSLC), but it doesn't factor T ! Also, but this is rather secondary, I would like to find the inverse of T (of course NOT to solve the linear equations system but for some other reason --- having T^{-1} allows to find some physical quantities, which, in effect, correspond to the solution of infinitely many R.H.S). In fact my T is complex, symmetric (but non-Hermitian), and has block-block-Toeplitz structure; but you may ignore this --- I will be happy with the general, real, block-Toeplitz solver. It seems there is a lot of theoretical work on this subject (see e.g. journal Lin. Alg.and Appl.) related to many diverse fields (multivariate analysis, image processing, etc.) but very little actual implementations ?! P. Flatau flatau@handel.colostate.edu ------------------------------ From: George Byrne Date: Mon, 22 May 89 10:21:39 EDT Subject: Help With NAMELIST Under Microsoft Fortran I am interested in locating a public domain Fortran routine, which will allow the use of NAMELIST under a Microsoft Fortran Compiler, version 4.01. (The request is for someone else.) Yes, I know that Lahey F77L supports NAMELIST. George Byrne ------------------------------ From: Art Werschulz Date: Mon, 22 May 89 14:53:48 EDT Subject: Stability of Negative Norm Projectors Hi. I need pointers to proofs of the following (if they're known). Please give a counterexample if they're false. They are described in (plain) TeX. In what follows, $s\ge 0$, $p\in(1,\infty]$, and $n$ is a nonnegative integer. We use more-or-less standard notation for Sobolev spaces, norms, inner products, and the like. Let $P_{-s,n}$ denote the orthogonal projector of the Sobolev space $H^{-s}(\Omega)$ onto a finite element subspace of dimension~$n$ and degree~$k$ (i.e., the subspace consists of piecewise-polynomials of degree at most $k$). Show that there is a constant $C$, independent of $n$, such that if $v\in W^{-s,p}(\Omega)$, then $$\|P_{-s,n} v\|_{W^{-s,p}(\Omega)} \le C \|v\|_{W^{-s,p}(\Omega)} .$$ Show that $$\|v\|_{W^{-s,p}(\Omega)} = \sup_{w\in L_{p'}(\Omega)} {|\langle v,w \rangle_{H^{-s/2}(\Omega)|} \over \|w\|_{L_{p'}(\Omega)}} $$ Thanks. Art Werschulz InterNet: agw@cs.columbia.edu BITnet: agw%cs.columbia.edu@cuvmb CSnet: agw%cs.columbia.edu@csnet-relay USEnet: ...!columbia!cs.columbia.edu!agw ATTnet: Columbia University (212) 854-8642 854-2736 Fordham University (212) 841-5323 841-5396 ------------------------------ From: David Womble Date: 24 May 89 08:08:00 MST Subject: Fellowship at Sandia National Laboratories RESEARCH FELLOWSHIP IN APPLIED MATHEMATICAL SCIENCES The Applied Mathematical Sciences Research Program at the Department of Energy is sponsoring a research fellowship in applied mathematics at Sandia National Laboratories. The fellowship will provide an outstanding research opportunity for young scientists who are actively pursuing leading-edge research in computational mathematics or numerical analysis. The successful candidate will have recently earned a doctorate in mathematics and will have made strong contributions to numerical computation or computer science. The fellowship appointment will be made in the Mathematics and Computational Science Department at Sandia, which has a strong research staff and provides an exceptional environment for the research and application of advanced parallel computing methods. The department maintains strong programs in analytical and computational mathematics, physics and engineering, as well as in advanced computational approaches for parallel computers, computer graphics, and computer architectures and languages. We also provide a unique parallel computing environment, including a 1024-processor NCUBE/ten, a Connection Machine and several large Cray supercomputers. Applications from qualified candidates should include a resume, a statement of research goals, and the names of three references. The fellowship appointment includes a highly competitive salary, moving expenses, and a generous professional travel allowance. If you are interested in this unique opportunity, please send your application to Robert H. Banks, Division 3531-86A Sandia National Laboratories P. O. Box 5800 Albuquerque, New Mexico 87185 The closing date for applications is July 31, 1989, and a successful candidate will be announced by September 15, 1989. Further inquiries can be made by calling R. C. Allen at (505) 844-2248. Equal Opportunity Employer M/F/V/H U.S. Citizenship is Required ------------------------------ From: David Whitley Date: Thu, 25 May 89 16:14:49 CDT Subject: Parallelizing the Simplex Method Bob Bixby and I are interested in finding out what work has been done on parallelizing the simplex method for linear programming. There is no work listed in the Science Citation Index from 1984 through Jan-Feb 1989 whose title contains both the word 'simplex' and any form of the word 'parallel'; this strongly suggests that no work on this subject has been published. If anyone has any information concerning this subject, we would appreciate it if you would let us know by writing to either bixby@rice.edu or whit@rice.edu. Thank you. David Whitley Rice University ------------------------------ From: Bill Venables Date: Tue, 23 May 89 13:18:30 CST Subject: Eigenvalues of Diagonally Perturbed Matrices Suppose S is a positive definite symmetric matrix and S(eps) is a scale perturbation of it, that is it has the form S(eps) = (I + eps)S(I + eps) where eps is a *diagonal* matrix of small entries. I am interested in expansions of the eigenvalues and eigenvectors of S(eps) about those of S near eps=diag(0). Does anyone know of work done in this area? Thanks in advance, Bill Venables (wvenable@spam.ua.oz@munnari.oz) ------------------------------ From: Ronald Thisted Date: Fri, 26 May 89 14:15:11 cdt Subject: Average-case Rounding Analysis Most numerical analysis books give error bounds for the accumulation of an inner product in terms of a worst case scenario, that is, errors at each step are assumed to have the same sign (no cancellation) and magnitude close to machine precision. [For example, Golub and Van Loan, p. 35] Can anyone supply pointers to the literature for analysis based on the average case? I am interested in three kinds of work: (a) assuming that errors are of the form tu, where u=machine eps, and t is uniform on (-0.5, 0.5), (b) empirical or theoretical investigations of the validity of the uniform assumption, and (c) any specific work on error bounds associated specifically with the inner-product computation. Thanks, Ronald Thisted Dept of Statistics/The University of Chicago thisted@galton.uchicago.edu ------------------------------ From: Yin Zhang Date: 26 May 89 21:17:17 GMT Subject: Sparse QR Factorization Does anybody know of the existence and availability of programs for sparse QR decomposition (in Fortran or C)? Pointers are appreciated. ~~~~~~ Yin Zhang Rice University, Houston ------------------------------ From: Howard Wilson Date: Sat, 27 May 89 12:03:42 CDT Subject: Forming a MATLAB Users Group I am an engineer interested in efficiently using computers to perform mathematical computations. After working with Fortran for many years, I recently became an entusiastic MATLAB user. There is a rapidly growing community of people who use MATLAB for algorithm development and other scientific computing tasks. This software gives a very friendly inter- active environment while providing powerful mathematical tools such as the major capabilities of LINPACK as well as functions for differential equation solution, Fourier transformation, numerical integration, spline interpolation, and graph plotting. Most of the functions and operators handle scalar, vector, or matrix arguments, and work with either real or complex quantities. The programming features of flexible function format and dynamic memory allocation make code development very easy. In fact, MATLAB combines most of the best features of Fortran and APL. The community of MATLAB is now large enough that a User Group would be helpful to communicate user experiences, interchange software, and cultivate wider usage of MATLAB. An inquiry made to original licensees of the software generated more than a hundred responses favoring formation of a user group. The current notice is made to contact other users who may not have been reached by the first inquiry. If you would like to join and participate in development of a MATLAB user group, please notify me so that we can include your name for receipt of future information. Send any replies to HWILSON@ua1vm.ua.edu ------------------------------ From: Gene Golub Date: Sun, 28 May 1989 11:50:38 PDT Subject: FAX Numbers I attach a list of FAX numbers which I have collected over the past several months. If you want to add your name or make a change, please send me a msg. Gene FAX numbers as of May 28, 1989. A "+" indicates an international number. Arizona State University : Hans Mittelmann 602-965-2012 ATT : Numerical Analysis : Eric Grosse 201-582-5857 CINECA, Bologna, Italy : Valeria Frontini +39-51-598472 Cornell University : Electrical Engineering : Franklin Luk 607-254-4565 Courant Institute : Michael Overton 212-998-3263 Duke University : Computer Science : Daniel B. Szyld 919-684-2097 ETH-Zurich : Martin Gutknecht +41-1-69-39-73 George Washington University : Mathematics : Murli Gupta 202-994-0458 Harwell : Iain Duff +44-235-832591 and +44-235-432375 Helsinki University of Technology : Mathematics : Olavi Nevanlinna +358-0-465077 IMA, UK : Catherine Richards +44-702-612610 Flinders University : Mathematics : Jerry Kautsky +61-8-277-1959 Minnesota : Mathematics : Hans Weinberger 612-626-2017 MIT : Mathematics : Nick Trefethen 617-253-4358 NBS : Francis Sullivan 301-975-2128 NSF : Kamal Abdali 202-357-7745 ORNL : Mathematics : Bob Ward 615-574-1274 Oxford Computing Lab : Bill Morton +44-865-273839 McGill University, Canada : Computer Science : Chris Paige 514-398-3883 Penn State University : Computer Science : Jesse Barlow 814-865-3176 Philips Lab, Belgium : Paul Van Dooren +32-2-674-2299 Princeton : School of Engineering : Bradley Dickinson 609-987-6744 Purdue University : Computer Science : John Rice Walter Gautschi 317-494-0739 Royal Institute of Technology : NADA : Germund Dahlquist +46-8-790-0930 Sandia : Juan Meza 415-294-2660 Joe Grcar 415-294-3057 SIAM : Administration 215-564-4174 Southern Methodist University : Mathematics : Ian Gladwell 214-692-4099 SRI : Julia Olkin : 415-859-4171 Stanford University : Computer Science: Gene Golub 415-725-7411 Electrical Engineering : Thomas Kailath 415-723-8473 University of Adelaide : Computer Science : Sylvan Elhay +61-8-223-1206 UBC : Computer Science : Jim Varah 604-228-7006 UCLA : Computer Science : Tony Chan 213-206-6673 UCSD : Mathematics : Jim Bunch 619-534-6774 United Technologies Research Center : Edward Smith 203-727-7310 University of Bergen : Bengt Aspfall and Petter Bjorstad +47-5-212857 University of California : John DePillis 714-787-3800 University of Fribourg, Switzerland : Mathematics : Jean-Paul Berrut +41-37-82-6519 University of Illinois : CSRD : Bill Harrod and Ahmed Sameh 217-244-1351 Computer Science : Bill Gear 217-333-3501 University of Leuven, Belgium : Marc Moonen +32-16-221855 University of Liverpool, England : R. Wait +44-51-708-6502 University of Maryland : UMIACS: Howard Elman 301-454-8346 University of Minnesota : IMA : Willard Miller 612-626-7370 University of New South Wales: School of Mathematics: Ian Sloan +61- 2- 662 6445 University of Technology, The Netherlands : Piet Wesseling +31-15-787022 University of Toronto : Computer Science : Ken Jackson 416-978-4765 University of Waterloo : Alan George 519-888-4638 Henry Wolkowicz 519-746-6592 Andrew R. Conn 519-746-6530 Vancouver, Computer Science : Uris Ascher 604-228-5485 Weidlinger Assoc. : Victor Pereyra 415-949-5735 Weizmann Institute, Israel : Uri Ascher +972-8-466-966 Xerox Park : John Gilbert 415-494-4471 ------------------------------ End of NA Digest ************************** -------