krj@na.toronto.edu (Ken Jackson) (05/15/89)
NA Digest Sunday, May 14, 1989 Volume 89 : Issue 19 Today's Editor: Cleve Moler Today's Topics: London Conference on Ordinary Differential Equations London Conference on Computational ODE Test Data for Mathematical Functions Fourth SIAM Conference on Parallel Processing for Scientific Computing Validation of Floating Point Operations in C Numerical C Extensions Group (NCEG) Meeting Report New Books From SIAM ------------------------------------------------------- From: Ronald England <R_ENGLAND%vax.acs.open.ac.uk@nsfnet-relay.ac.uk> Date: 9-MAY-1989 14:41:47 GMT Subject: London Conference on Ordinary Differential Equations Following various comments which have been circulating in connection with the IMA Conference on Computational Ordinary Differential Equations, I wish to circulate, as widely as possible, the following statement on behalf of the organising committee, together with an updated version of the conference application form. We were well aware, from an early stage, that London would be an expensive location in which to organise a conference. Imperial College insisted upon charging the IMA at commercial rates, and we were unsuccessful in our requests for external funding. We have also made arrangements for what we think is an impressive list of invited and highlighted speakers, all of whom require some financial support. Nevertheless, when the IMA officers calculated and announced the level of fees for the conference, we were greatly disturbed to discover that these were far in excess of that which we had been expecting. You will probably have read the justification of those fees which has been circulated by Catherine Richards, Secretary and Registrar of the IMA, and which was accompanied by an announcement of a new, reduced level of fees. While these fees are still higher than we would have hoped for, and while we feel that they should not be taken as a precedent by organisers of future conferences when calculating their costs and fees, we must nevertheless express our gratitude to the IMA officers and others who have made an effort to bring down the costs of the meeting. In spite of some of the unfortunate comments which have been made, we hope that the conference will now be able to go ahead, and that, with the support of all the interested community, it will be as successful an event as any of the previous conferences on a similar subject area. May I also take this opportunity of reminding you that this meeting will take place in the week following the regular Numerical Analysis Conference at the University of Dundee. Those of you who may be coming from outside Great Britain will therefore be able to share you travelling expenses between the two conferences. We look forward to seeing as many of you as possible in London. Roland England R_ENGLAND@VAX.ACS.open.AC.UK Rengland@nsfnet-relay.ac.uk NA.rengland@na-net.stanford.edu APPLICATION FORM Conference on COMPUTATIONAL ORDINARY DIFFERENTIAL EQUATIONS Imperial College, London 3rd-7th July, 1989 The IMA is organising a conference on Computational Ordinary Differential Equations, to be held at Imperial College, London, in July, 1989. The aim of this meeting is to bring together research workers and practitioners in theory and algorithms for the numerical solution of ordinary differential equations . All relevant topics are to be covered and contributions in application areas will be encouraged . The invited speakers are: # J.C. Butcher (Auckland) # H.B. Keller (Caltech) # R.E. O'Malley Jr. (Rensselaer Polytech. Inst.) # L.R. Petzold (Lawrence Livermore) # R.D. Russell (Simon Fraser, Vancouver) # J.M. Sanz-Serna (Valladolid) # L.F. Shampine (Southern Methodist, Dallas) # M.N. Spijker (Leiden) Talks by the following speakers will also be highlighted: # U. Ascher (British Columbia) # G. Bader (Heidelberg) # G.D. Byrne (Exxon Research) # G.F. Corliss (Milwaukee) # U. Kirchgraber (ETH, Zurich) # J.F.B.M. Kraaijevanger (Leiden) # J. Lawson and M. Berzins (Leeds) # B.J. Leimkuhler and O. Nevanlinna (Helsinki) # H.W. Tam (Illinois) The programme will also include quite a number of shorter 20 minute contributed papers , and posters . An optional visit to Hampton Court Palace will be organised on the afternoon of Wednesday, 5th July . This afternoon is free from lectures . Members of the Organising Committee for the conference are: Dr. J.R. Cash (Imperial College of Science and Technology, London), Dr. R. England, AFIMA (The Open University, Milton Keynes), Prof. I. Gladwell, FIMA (Southern Methodist University, Dallas) and Dr. A. Iserles, AFIMA (University of Cambridge). Authors who have been notified that their papers have been accepted for presentation are now invited to submit them for publication in the proceedings , which are to be published by Oxford University Press in the IMA Conference Proceedings Series . In order to expedite the refereeing procedure , full papers should be submitted before the end of the meeting . FEES in Pounds Sterling (including VAT at 15%) VAT Reg. No. 250 4466 77 Members Non-Members Bona-fide Bona-fide Postgraduate Postgraduate Student Student Conference fee Members Non-Members (including coffee, lunch and tea on 3rd-7th July, inclusive) 115.00 145.00 85.00 100.00 Residential fee (including dinner, bed and breakfast at Imperial College in single study bedrooms for the nights of 2nd-6th July 120.00 120.00 inclusive, and conference dinner on 6th July -Alternatively please write for a list of local hotels Non-residents only Conference dinner on 6th July 30.00 30.00 Visit to Hampton Court Palace (including entrance to Palace and Maze and coach) 8.00 8.00 Late registration fee Applications received later than 2nd June 10.00 10.00 Applications received later than 23rd June 15.00 15.00 Invoice fee 10.00 10.00 ........................................................................... To: Miss Yvonne May, Conference Officer The Institute of Mathematics and its Applications Maitland House, Warrior Square Southend-on-Sea, Essex SS1 2JY, England Conference on COMPUTATIONAL ORDINARY DIFFERENTIAL EQUATIONS Imperial College, London 3rd-7th July, 1989 MALE FEMALE TITLE NAME INSTITUTION AT WHICH EMPLOYED (in full) ADDRESS FOR CORRESPONDENCE CONFERENCE FEE RESIDENTIAL FEE CONFERENCE DINNER (non-residents only) LATE REGISTRATION FEE INVOICE FEE HAMPTON COURT FEE SPECIAL DIETARY REQUIREMENTS SIGNATURE GRADE (if IMA member) DATE Please charge my Access Account Number If your Access card account address is different from the above address , please enter here: All cheques should be made payable to The Institute of Mathematics and its Applications. ------------------------------ From: Hans Stetter <E115N06%AWITUW01.BITNET@Forsythe.Stanford.EDU> Date: 10 MAY 89 15:53:37 Subject: London Conference on Computational ODE From Ronald England`s announcement in this na-digest you will have seen that the Organizing Committee of the Computational ODE Conference has finally decided to hold the conference as planned. Obviously, their decision was moti- vated not so much by the reduction of the conference fee which has been ach- ieved but by the consideration of the huge effort which has been invested in this conference by so many people. Since I have served as the catalyst who brought to light the dissatis- faction of a great many of you, I feel that I should also speak up at this point. Naturally, I cannot claim that the complaints which I had voiced have become immaterial now. However - putting myself in the position of a member of the Organising Committee in this moment - I must admit that I would have reached the same conclusion: It would simply have been grossly unfair to all those who have spent long hours in preparing their talks for us to cancel this meeting two months before its scheduled time. Also, a good number of you will have committed themselves by the purchase of non-refundable reduced airline tickets and the like. Besides, I am certain that this will be an outstanding meeting from the scientific point of view. The selection of the invited and highlighted speak- ers is impressive, and there will be many more highly stimulating contributed papers - judging from the few that have come to my knowledge. All that remains in order to make this conference a full scientific success is our own parti- cipation! Therefore, I have decided to go to London for the conference - and I would like to urge all of you who work in computational ODEs to try hard to be there. Scientific meetings consist not just of the papers which are delivered (and which could also be read at home) but of the colleagues and friends you meet and of the information you get in conversation. And this cannot be had by staying away! Finally, a word of thanks to all who have responded to my previous ap- peals in one way or other; excuse me for not being able to answer each of you personally. I am quite sure that this example will not go unnoticed, and you have contributed to its (partial) success. See you in London! So long, Hans J. Stetter. ------------------------------ From: Chris Henrich <sun.soe.clarkson.edu> Date: 5 May 89 19:00:17 GMT Subject: Test Data for Mathematical Functions I would like to get my hands on data to help me test the accuracy of mathematical functions. The functions in question are "elementary" - square root, exponential, logarithm, direct & inverse trigonometric, etc. The data that I want are pairs (x, f(x)) in IEEE floating-point formats, both single and double precision. I have already looked at one large catalogue of microcomputer software, and drawn a blank. Commercially marketed stuff seems to be programs, which actually *do* interesting stuff. What I am after is a bunch of numbers that just sit there. Any pointers toward such data, or toward catalogues of resources like that, will be gratefully received. Regards, Chris Perkin-Elmer DSG, Tinton Falls, N.J. UUCP: ...!rutgers!petsd!cjh (201)758-7288 106 Apple Street, Tinton Falls,N.J. 07724 ------------------------------ From: Jack Dongarra <dongarra@antares.mcs.anl.gov> Date: Thu, 11 May 89 17:19:44 CDT Subject: Fourth SIAM Conference on Parallel Processing for Scientific Computing Title: Fourth SIAM Conference on Parallel Processing for Scientific Computing Place: Chicago, Illinois Conference Date: December 11-13, 1989 Abstract Deadline: June 1, 1989 Contact: SIAM Conference Coordinator 117 S. 17th Street, 14th Floor Philadelphia, PA 19103-5052 USA 215-564-2929 E-Mail: SIAM@WHARTON.UPENN.EDU FAX: 215-564-4174 Purpose: The conference will focus on the development of analytic methods, efficient algorithms, and applications software in context with advances in computer architecture as applied to high-performance systems. SIAM has selected these areas for a conference because of the growing recognition of the importance of exploiting massive parallelism to attack complex problems. In addition to new computational algorithms there is a tremendous need for tools to aid the development of programs for these new high performance computers and also the need to develop new tools to aid scientists in the visualization and analysis of their data. SIAM believes that the development of effective large-scale high-performance scientific computing systems depends, at least in part, on the continued interaction of algorithm developers, numerical analysts, computer architects, and scientists concerned with scientific computing. Topics: Massively parallel computing, visualization of scientific computation, tools for parallel algorithm development, and many other related subjects. Speakers: Alan Egolf, United Technologies Research Center Dennis B. Gannon, Indiana University, Bloomington David Gelernter, Yale University. William Goddard, California Institute of Technology W. Danny Hillis, The Thinking Machines Corporation Ken Kennedy, Rice University James Sethian, University of California, Berkeley Andries van Dam, Brown University Karl-Heinz A. Winkler, Los Alamos National Laboratory How to Register: Advance registration material will be available in late September 1989. To ensure receiving your registration material and preliminary program, please send a request to siam@wharton.upenn.edu or call: (215) 564-2929. HOW TO CONTRIBUTE: Contributed and poster presentations are invited in all areas consistent with the conference themes. A description of your presentation must be submitted on a SIAM abstract form, which can be obtained by contacting SIAM. A contributed presentation will be considered for one of the following categories, a 30-minute talk, a 20-minute talk or a poster presentation. When submitting your abstract, please indicate the type of presentation for which you would like to be considered. A limited number of papers will be selected for 30-minute talks, but all others will be considered for 20-minute talks or poster presentations. In addition, we also ask that you submit an extended abstract, typed on plain white bond, of 750 words and also an abstract of 100 words submitted on a SIAM Abstract Form. The reason for this is that the 100 word abstract will be used in the description of your talk in the program and the 750 word abstract will be used in selecting papers to be presented at the conference. The selection of papers will be made in the first week of July 1989. VENDOR PRESENTATIONS: The conference organizers have set aside exclusive times and meeting rooms for vendors to give brief presentations about their products and services. A brief description of your talk, not exceeding 100 words, must be submitted on a SIAM abstract form, which can be obtained by completing the attached postage-paid reply card and returning it to SIAM. [Ed. Note-- Attached to what, Jack?] A presentation consists of a seventeen-minute talk, followed by three minutes for questions. ------------------------------ From: Steve Snelgrove <...!wicat!steves> Date: 11 May 89 21:38:30 GMT Subject: Validation of Floating Point Operations in C I am trying to find a C compiler for the IBM PC which supports IEEE floating point. Surprisingly (at least to me), this has turned out to be a very unsuccessful effort. While many compilers allow access to a coprocessor via the hardware floating point instructions, the corresponding software routines do not produce the same results. The tool I am using in my investigations is a C program which performs arithmetic according to the standard. I have implemented four operations on the type 'double': add, subtract, multiply, and divide. The test driver portion of the program uses an array containing about 100 entries of both positive and negative values representing zeros, subnormals, normals, infinities, and NaN's. Two nested 'for' loops are used to generate the power set of these elements. For each pair of values, an operation is performed twice, once using the simulation and then again using the intrinsic operation. The results are then compared for equality. Command line options control the selection of tests and the printing of results. For each operation, a summary report is displayed which should be of the form: ADD ZERO SUBNORMAL NORMAL INFINITY NAN +-----------+-----------+-----------+-----------+-----------+ ZERO | 100% | 100% | 100% | 100% | 100% | SUBNORMAL | 100% | 100% | 100% | 100% | 100% | NORMAL | 100% | 100% | 100% | 100% | 100% | INFINITY | 100% | 100% | 100% | 100% | 100% | NAN | 100% | 100% | 100% | 100% | 100% | +-----------+-----------+-----------+-----------+-----------+ The test shown above was generated by a 68881 coprocessor. I have at this location a 68000/68881 machine and several IBM machines, one of which has a 80287. I have tried an early version of the simulation on an 80387. All of the coprocessor results seem to agree at least with regards to my test values. Two exceptions are experienced as a result of incorrect initialization and interrupt support when using either an 8087 or an 80287. It seems to me that the C startup code should set the infinity mode on 8087's and 80287's to affine mode rather than the default which is projective. This will cause these chips to perform according to the standard and in the same manner as an 80387 which only supports affine mode. I also think that the C startup code should supply an interrupt handler which will normalize subnormal (denormal) operands. I think that this will prevent the generation unnormalized results in multiply and divide. The storing of unnormalized values causes an invalid operation exception. The IEEE standard requires normalizing mode. I believe that these two steps are required in the startup code. I have worked with both the Lattice and the Microsoft C compilers and have not found these steps to be present. This does not surprise me too much in the case of Lattice since their only support of the standard is in the use of the storage formats. All underflows are forced to zero, infinities and NaN's are not recognized, and subnormals cause 'printf' to go into an infinite loop. Microsoft does the best job I have seen for the IBM PC. Still they do some funny things like force the sign of zero to be positive (but only after returning from a subroutine?). The standard indicates that the default mode of operation should be with exceptions masked. Microsoft requires a call to a 'control87' function to mask exceptions. I also experienced a problem when multiplying a subnormal and a normal resulting in invalid as described above. The software emulation correctly produced a result. However, when run on the machine with the 80287 the exception was not masked and caused execution to terminate with an error message. Another problem was observed in operations involving two NaN's. Apparently an attempt was made to emulate the operation of the coprocessor which returns the NaN with the larger magnitude. However, the comparison was made from LSW to MSW instead of from MSW to LSW. As a side note on operations with NaN's, the 80387 manual seems to indicate that Signaling NaN's will be converted to Quiet NaN's by setting the high order bit in the fraction. I did not see this on the one 80387 I tried. Are there differing versions of the 80387 or maybe I goofed by not having enough NaN cases when I did the test? Another C related issue which caused me considerable confusion and delay is that of the double rounding which can occur when results are first rounded to the size of the internal registers (extended) and then rounded again when storing to a double. The only mention of this that I can recall having seen is in the Apple Numerics Manual. On page 38 of the second edition, they state: | The IEEE Standard encourages extended-precision expression evaluation. | on rare occasions, extended evaluation produces results slightly | different from those produced by other IEEE implementations that lack | extended evaluation. Thus, in a single-only IEEE implementation, | | z := x + y; | | with x, y, and z all single, is evaluated in one single precision | operation, with at most one rounding error. Under extended evaluation, | however, the addition of x + y is performed in extended; then the result | is coerced to the single precision of z, with at most two rounding errors. | Both implementations conform to the standard. This seems to directly contradict the wording of the standard which says in section 4.3 that: | ..., a system that delivers result only to double extended destinations | shall permit the user to specify rounding to single or double precision. | Note that to meet the specifications in 4.1, the result cannot suffer | more than one rounding error. How is Apple justified in their statement made above? Apple seems to be the only company which has really tried to provide full IEEE floating point support to the users of high level languages. What kind of feelings do people hold about the success of their efforts? Have they adequately covered all of the relevant issues with regards to users requirements for control and usage of the floating point environment? Is there anything as well defined available for other machines? My test program has been posted to the newsgroup sci.math.num-analysis. If you don't have access to that network, and would like a copy, please contact me directly. Steve L. Snelgrove WICAT Systems Research and Development 748 N. 1340 W. Orem, UT 84057 (801)224-6605 ------------------------------ From: Rex Jaeschke <aussie!rex@uunet.uu.net> Date: 13 May 89 23:49:10 GMT Subject: Numerical C Extensions Group (NCEG) Meeting Report The following report is reprinted from Volume 1, Number 1 (June 1989) of The Journal of C Language Translation, Copyright 1989 Rex Jaeschke. Permission is granted for duplication and distribution of this report for the purposes of furthering the work of NCEG. Numerical C Extensions Group Status Rex Jaeschke NCEG Convener Introduction When I conjured up the idea for an ad hoc group to define numerical extensions to C earlier this year, I had no idea as to what the reaction would be. The evidence is now clear that this endeavor is seen as being very worthwhile. Not only have more than 90 people asked to be added to the contact database, but 30 of them attended the one-and-a-half day meeting at Cray Research on May 10--11. The backgrounds of the attendees was diverse. The supercomputing industry was represented via Cray, Convex, Supercomputer Systems, and Thinking Machines. The IEEE community was well represented by Hough (from Sun), Cody (from Argonne Labs), and Thomas (from Apple.) Other organizations represented included Unisys, Microsoft, Digital Equipment Corporation, H-P, CDC, IBM, Solborne, Farance, Inc., University of Minnesota, Intermetrics, and Information and Graphics Systems. The digital signal processing industry was represented by Analog Devices, and LLNL, Army BRL, and Polaroid Corporation represented the user community. Dennis Ritchie from AT&T also participated. There was no real sentiment that we deliberately go against the direction established by ANSI C. In fact, quite the contrary. However, it was recognized that some of ANSI C's constraints may impede our activities resulting in possible conflicts. The whole issue of errno and formatted I/O of NaNs and infinity are examples. The Issues The main purpose of the meeting was to identify and prioritize the principal technical issues. The group then voted on each topic indicating high or medium (or no) priority. The high priority votes were weighted twice as much as the medium, and the following list of priorities resulted. Main Numerical Issues Topic Priority aliasing 29 vectorization 27 complex 27 variably dim arrays 25 IEEE issues 24 exceptions/errno 24 float/long double library 23 parallelization 22 ANSI <math.h> 21 array syntax 19 extra math functions 17 aggregate initializers 15 inter-language issues 15 wide accumulators 10 math function precision 9 non-zero-based arrays 8 numerical representation 6 new data types 4 new operators 4 function overloading 4 Another topic, ``Arrays as first class objects'' had a high priority (21) but after considerable debate was dropped from the list since it was agreed its addition would likely cause great confusion to existing C programmers. Formation of Subgroups The bulk of the agenda time was then given to the top ten topics, each getting 20--30 minutes. For each of these topics, attendees volunteered to be the primary and alternate coordinator. (The minutes of the first meeting identify these people. In the interim, contact me for details.) The intent is that the real technical work will go on between meetings and be coordinated by the leaders of each subgroup. Then, at the following meeting, each subgroup will present the results of its work and make formal proposals as appropriate. This way, the committee can focus on the final, distilled issues rather than everyone getting involved at all levels. It will also significantly reduce the amount of paper in the mailings. If you wish to participate in any of these subgroups it is your responsibility to contact the leaders and identify yourself, your concerns and how you can help. If your area of interest is not listed here, start your own subgroup and let me know. Mailings and Submissions Most of people interested in NCEG appear to have an e-mail address so that should make the subgroups' job much easier in coordinating various viewpoints and proposals. However, all formal distributions will be by paper mail. Since meetings are to be once every six months there will be two mailings between meetings. The first will occur within 4--6 weeks after a meeting and will contain minutes, new papers and other appropriate correspondence. The second will occur about 4--6 weeks prior to the following meeting. The cut-off date for formal submissions for the September meeting is August 11. Forward all correspondence to me (either by mail or via uunet!aussie!rex) and I will assign it a document number. (Note that I do not have a troff formatter.) However, do that only if your paper is concerned with issues other than those being handled by the subgroups. For subgroup issues, forward papers to the subgroup coordinators so they can include it in their submissions to me. The intent is to avoid excessive duplication of points and to allow the short meeting time to be used more effectively. The more formal documents we have the slower it will go. Tom MacDonald at Cray Research has agreed to do the mailings, at least for the interim. Frank Farance of Farance, Inc., has volunteered to be the redactor of the group's working document. Thanks to Tom and Frank. (Thanks also to Randy Meyers from DEC, who acted as meeting secretary and to Cray for being meeting host.) Formal Affiliation There was general consensus that we become affiliated with a recognized standards organization. The final proposal was that we become a working group within X3J11. If we follow that route, it will result in our publishing a Technical Report, a non-binding report on our findings and recommendations. With suitable planning, we might be able to have that elevated to a Technical Bulletin and get it distributed with the ANSI Standard. Getting our extensions adopted as a standard is also possible, in the long term. At this stage, I plan to ask for agenda time at the next X3J11 meeting to discuss admitting us as a work group. In the interest of economy, the next two meetings are scheduled in the same location and week as those of ANSI C's X3J11. These NCEG meeting dates are September 19--20 (Salt Lake City, Utah), and March 7--8, 1990 (New York City.) Rex Jaeschke | C Users Journal | Journal of C Language Translation (703) 860-0091 | DEC PROFESSIONAL |1810 Michael Faraday Drive, Suite 101 uunet!aussie!rex | Programmers Journal | Reston, Virginia 22090, USA ------------------------------ From: Kathleen LeBlanc <SIAM@wharton.upenn.edu> Date: Mon, 8 May 89 11:31 EDT Subject: New Books From SIAM TITLE: Mathematical Aspects of Vortex Dynamics SERIES: Proceedings in Applied Mathematics EDITOR: Russel E. Caflisch Courant Institute of Mathematical Sciences, New York University 224 pages, softcover, ISBN 0-89871-235-1, April 1989 LIST PRICE: $29.50 This volume presents 19 papers representing the invited and contributed talks at the workshop on Mathematical Aspects of Vortex Dynamics, held at the Xerox Training Center in Leesburg, Virginia, on April 25-27, 1988. The book discusses a variety of fluid problems, including vortex sheets and shear layers, the vortex reconnection problem, vortex methods, coherent vortex structures, fluid dynamic stability, systems of point vortices, turbulence modeling and other applications. It is written for students and researchers working in the area of fluid dynamics, including mathematicians, engineers and physicists. Anyone wishing to survey the current state of the subject of vortex dynamics is especially encouraged to order this book. Knowledge of fluid dynamics is a recommended prerequisite. CONTENTS: Mathematical Analysis of Vortex Dynamics, Russel E. Caflisch; Improved Vortex Methods for Three-Dimensional Flows, G. Winckelmans and A. Leonard; The Relation Between Thin Vortex Layers and Vortex Sheets, M.J. Shelley and G.R. Baker; Computations of Broad Band Instabilities in a Class of Closed-Streamline Flows, B.J. Bayly; Vortex-Sheet Dynamics and Some References to Hyperfunction Theory, T. Kambe; A Free Surface Vortex Method with Weak Viscous Effects, T.S. Lundgren; An Iterative Method for Computing Steady Vortex Flow Systems, Bruce Turkington and Alexander Eydeland; On Invariant Measures for the 2-D Euler Flow, Mario Pulvirenti; On Similarity Flows Containing Two-Branched Vortex Sheets, D.I. Pullin; Strain-Induced Vortex Stripping, David G. Dritschel; Convergence of the Vortex Method for Vortex Sheets, John S. Lowengrub; Boundary Conditions and Deterministic Vortex Methods for the Navier-Stokes Equations, Georges-Henri Cottet; Observations on Vorticity Creation Boundary Conditions, Christopher R. Anderson; Vortex Dynamics of Stratified Flows, Gretar Tryggvason; Remarks on Vortex Breakdown, Mel S. Berger; Numerical Studies of Vortex Reconnection, D.I. Meiron, M.J. Shelley, W.T. Ashurst, and S.A. Orszag; Vortex Lattices in Theory and Practice, Laurence J. Campbell; The dynamics of Vortex Structures in the Wall Region of a Turbulent Boundary Layer, John L. Lumley; The Energy of a Vortex Lattice Configuration, Kevin A. O'Neill ============ TITLE: Combinatorial Algorithms: An Update SERIES: CBMS-NSF Regional Conference Series in Applied Mathematics EDITOR: Herbert S. Wilf, Professor of Mathematics, University of Pennsylvania 56 pages, softcover, ISBN 0-89871-231-9, April 1989 LIST PRICE: $12.00 Combinatorial Algorithms: An Update focuses on some of the exciting, vigorous new work being done in this field, including recent developments in algorithms for generating combinatorial objects such as partitions, Gray codes, and trees. This monograph is a comprehensive update of Combinatorial Algorithms by Wilf and Albert Nijenhuis, which was first published in 1975 and revised in 1978. It is based on a series of ten lectures given by Wilf at the CBMS-NSF Conference on Selection Algorithms for Combinatorial Objects held in 1987 at Colorado College. This volume presents a survey of some of the new work that has been done since the appearance of the second edition of Combinatorial Algorithms. Topics that are discussed include progress in the following areas: Gray Codes, listing of subsets of given size of a given universe, listing rooted and free trees, selecting free trees and unlabeled graphs uniformly at random, and ranking and unranking problems on unlabeled trees. This book is excellent for graduate students, researchers, and computer science professionals in discrete mathematics, with the only prerequisite being the successful completion of a high-level undergraduate course in combinatorics. CONTENTS: The Original Gray Code; Other Gray Codes; Variations on the Theme; Choosing 2-Samples; Listing Rooted Trees; Random Selection of Free Trees; Listing Free Trees; Generating Random Graphs; Bibliography ============ TITLE: Stochastic Processes in the Neurosciences EDITOR: Henry C. Tuckwell SERIES: CBMS-NSF Regional Conference Series in Applied Mathematics No. 56 136 pages, softcover, ISBN 0-89871-232-7, May 1989 LIST PRICE: $24.50 This monograph is centered on the quantitative analysis of nerve-cell behavior. The work is foundational, with many higher order problems still remaining, especially in connection with neural networks. Thoroughly addressed topics include stochastic problems in neurobiology, and the treatment of the theory of related Markov processes. Special features include systems of nonlinear stochastic partial differential equations and the pertubative approach to their solutions; comprehensive treatment of channel noise; and statistical analysis of point processes; Wiener kernel explanations. Mathematicians, especially probabilists and statisticians interested in new applications, will appreciate Tuckwell's work, as will neurobiologists. Background requirements include intermediate probability and related mathematics, as well as a rudimentary knowledge of neurophysiology. CONTENTS: Deterministic Theories and Stochastic Phenomena in Neurobiology; Synaptic Transmission; Early Stochastic Models for Neuronal Activity Including Poisson Processes and Random Walks; Discontinuous Markov Processes with Exponential Decay; One-dimensional Diffusion Processes; Stochastic Partial Differential Equations; The Statistical Analysis of Stochastic Neural Activity; Channel Noise; Wiener Kernel Expansions; The Stochastic Activity of Neuronal Populations ============ TITLE: Parallel Processing and Medium Scale Multiprocessors SERIES: Proceedings in Applied Mathematics EDITOR: Arthur Wouk, Mathematical Sciences Division, Army Research Office 216 pages, softcover, ISBN 0-89871-238-6, June 1989 LIST PRICE: $31.50 The papers in this book represent those presented at the ARO research workshop on Parallel Processing and Medium Scale Multiprocessors held at Stanford University in January 1986. The workshop brought together research workers with strong connections to scientific computation as well as an interest in the systems programming problems that are restricting the application of the new hardware being developed. This volume contains papers covering several areas, including systems programming, parallel language/programming systems, and applications programming. The work reported includes investigations into debugging of operating systems, portability of applications programs and parallel operating systems, efficient resource allocation in multiprocessors, parallel constructs for applications programming languages, and applications programming efforts on diverse architectures. These papers can provide helpful guidance for those wishing to explore the new territory of automatic optimal parallelization of sequentially conceived programs. This book will be a useful guide for all researchers having an interest in scientific computation, especially those wishing to explore more thoroughly the problems involved in automatic optimization in the compilation of parallel programs. CONTENTS: Debugging Multi-Task Programs, Morven Gentleman and Darlene Stewart; Matrix Computations and Game Playing on the iPSC, Cleve Moler and David Scott; A System for Parallel Processing, P. O'Leary, G.W. Stewart, and Robert van de Geijn; Statistical Methodologies for the Control of Dynamic Remapping, Joel Saltz and David Nicol; Sparse Cholesky Factorization on a Local-Memory Multiprocessor, Alan George, Michael Heath, Joseph Liu and Esmond Ng; Concurrent Global Optimization on a Network of Computers, Richard Byrd, Cornelius Dert, Alexander Rinooy Kan, and Robert Schnabel; Heterogeneous Processes on Homogeneous Procesors, George Cybenko, David Krumme, K.N. Venkataraman and A. Couch; Matrix Multiplication on Boolean Cubes using Generic Communication Primitives, Lennart Johnsson and Ching-Tien Ho; The Force on the Flex: Global Parallelism and Portability, Harry Jordan; SCHEDULE: An Aid to Programming Explicitly Parallel Algorithms in Fortran, J. Dongarra and D.C. Sorenson; Dynamic Grid Manipulation for PDEs on Hypercube Parallel Processors, William D. Gropp; Solving Compressible Euler Equations on a Hypercube Simulator, Jung Pyo Hong, Bob Tomlinson, and Nisheeth Patel ============ FOR ORDERING INFORMATION AND REVIEW COPIES (USA ONLY), PLEASE CONTACT KATHLEEN LE BLANC AT SIAM. Phone: (215)564-2929; E-mail: siam@wharton.upenn.edu ------------------------------ End of NA Digest ************************** ------- Reposted by -- Kenneth R. Jackson, krj@na.toronto.edu (on Internet, CSNet, Computer Science Dept., ARPAnet, BITNET) University of Toronto, krj@na.utoronto.ca (CDNnet and other Toronto, Canada M5S 1A4 X.400 nets (Europe)) (Phone: 416-978-7075) ...!{uunet,pyramid,watmath,ubc-cs}!utai!krj