From knauer at inf.fu-berlin.de Mon Aug 5 21:41:58 2002 From: knauer at inf.fu-berlin.de (Christian Knauer) Date: Mon Jan 9 13:41:07 2006 Subject: [DMANET] STACS 2003 -- 2nd Call for papers Message-ID: <15694.50934.362182.396037@gargle.gargle.HOWL> ============================================================== We apologize for multiple copies of this call for papers ============================================================== +--------------------+ | | | STACS 2003 | | | +--------------------+ 20th International Symposium on Theoretical Aspects of Computer Science Berlin, Germany February 27 - March 1, 2003 http://www.inf.fu-berlin.de/~stacs2003 SCOPE: Authors are invited to submit papers presenting original and unpublished research on theoretical aspects of computer science. Typical areas include (but are not limited to): * Algorithms and data structures, including: parallel and distributed algorithms, computational geometry, cryptography, algorithmic learning theory; * Automata and formal languages; * Computational and structural complexity; * Logic in computer science, including: semantics, specification, and verification of programs, rewriting and deduction; * Current challenges, for example: theory, models, and algorithms for biological computing, quantum computing, mobile and net computing. SUBMISSIONS: Authors are invited to submit a draft of a full paper with at most 12 pages, the title page must contain a classification of the topic covered, preferably using the list of topics above. The paper should contain a succinct statement of the issues and of their motivation, a summary of the main results, and a brief explanation of their significance, accessible to non-specialist readers. Proofs omitted due to space constraints must be put into an appendix to be read by the program committee members at their discretion. Electronic submission is highly recommended. In case of problems with access to internet, it is possible to submit 6 copies of the complete draft and 15 copies of a one page abstract to the chairperson of the program committee. Detailed information is available on the web site. IMPORTANT DATES: Deadline for submission: September 7, 2002 Notification to authors: November 6, 2002 Final version: December 6, 2002 Symposium: February 27 - March 1, 2003 PROCEEDINGS: Accepted papers will be published in the proceedings of the Symposium (Lecture Notes in Computer Science, Springer-Verlag). Simultaneous submission to other conferences with published proceedings is not allowed. PROGRAM COMMITTEE: H. Alt (Free University of Berlin) Chair A. Bouajjani (LIAFA, Paris) B. Durand (LIF, Marseille) P. Fraigniaud (LRI, Orsay) M. Goldwurm (University of Milan) M. Grohe (University of Edinburgh) R. Grossi (University of Pisa) M. Habib (LIRMM, Montpellier) Co-Chair R. Impagliazzo (UC San Diego) M. Krause (University of Mannheim) P.B. Miltersen (University of Aarhus) D. Niwinski (University of Warsaw) G. Senizergues (LaBRI, Bordeaux) H.U. Simon (Ruhr-University of Bochum) R. Wanka (University of Paderborn) INVITED SPEAKERS: Ernst W. Mayr (TU Munich) Alain Viari (INRIA, Grenoble) Victor Vianu (UC San Diego) CONFERENCE CHAIR: Helmut Alt Institut f?r Informatik Freie Universit?t Berlin Takustra?e 9 D-14195 Berlin Germany ORGANIZING COMMITTEE CHAIR: Christian Knauer E-ADDRESS: stacs03@inf.fu-berlin.de WEB SITE: http://www.inf.fu-berlin.de/~stacs2003 ==== please post and distribute ==== ********************************************************** * * Contributions to be spread via DMANET are submitted to * * DMANET@zpr.uni-koeln.de * * Replies to a message carried on DMANET should NOT be * addressed to DMANET but to the original sender. The * original sender, however, is invited to prepare an * update of the replies received and to communicate it * via DMANET. * * DISCRETE MATHEMATICS AND ALGORITHMS NETWORK (DMANET) * http://www.zpr.uni-koeln.de/dmanet * ********************************************************** From padmajaveerapaneni at yahoo.com Sun Aug 4 19:22:07 2002 From: padmajaveerapaneni at yahoo.com (padmaja veerapaneni) Date: Mon Jan 9 13:41:07 2006 Subject: circumcentre Message-ID: <20020805012207.78568.qmail@web20418.mail.yahoo.com> Hi Can you please tell me what EXACT is in the code of Circumcentre of a Tetrahedron . regards Padmaja __________________________________________________ Do You Yahoo!? Yahoo! Health - Feel better, live better http://health.yahoo.com ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From funke at mpi-sb.mpg.de Fri Aug 2 18:35:01 2002 From: funke at mpi-sb.mpg.de (Stefan Funke) Date: Mon Jan 9 13:41:07 2006 Subject: ADFOCS 2002 -- Call for Participation Message-ID: <3D4AA6A5.BD5E0302@mpi-sb.mpg.de> (please forward to potentially interested students and postdocs) * CALL FOR PARTICIPATION * 3nd Max-Planck Summer School Advanced Course on the Foundations of Computer Science ADFOCS 2002 Saarbr?cken, Germany, September 9-13, 2002 http://www.mpi-sb.mpg.de/~adfocs PROGRAM ------- The program consists of 12 lecture blocks and 8 tutorial/discussion sessions. The speakers and topics are the following. - Timothy Chan, University of Waterloo: Random Sampling - Michele Mosca, University of Waterloo: Quantum Computing - Prabhakar Raghavan, Verity Inc.: Randomized Algorithms and the Probabilistic Method - Gerhard W?ginger, University of Twente: Approximation Algorithms and Inapproximability ABOUT ADFOCS ------------ ADFOCS is organized as part of the activities of the Algorithms and Complexity Group and the International Max-Planck Research School of the Max-Planck-Institut f?r Informatik. The scope of ADFOCS is international and it is addressed mainly to young researchers at the PhD student or postdoc level. The goal of ADFOCS is to provide an overview of selected topics from the foundations of computer science and to highlight major research directions in these areas. This years ADFOCS will address topics like random sampling, randomized algorithms, approximation algorithms as well as quantum computing. The course will highlight important problems, techniques and ongoing research in these areas. It will also emphasize the discussion of open problems and the active involvement of the participants, thus strengthening the links of cooperation between young researchers of the field. LOCATION & TRAVEL INFORMATION ----------------------------- ADFOCS will be held at the Max-Planck-Institut f?r Informatik in Saarbr?cken. Saarbr?cken is the capital of one of Germany's 16 states, the Saarland. It is conveniently located in the center of Europe, on the border of Germany with France, between Luxembourg, the Saar-Mosel valley, Frankfurt and Strasbourg. Being located on several main train and road routes, Saarbr?cken is easily reachable from Frankfurt, Stuttgart, Paris or Luxembourg. It also has its own international airport. REGISTRATION ------------ The registration fee covers lunches and social events. The early registration deadline has already passed. Now the registration fee is Euro 150. Please note that the registration fee does not include accommodation, although MPI can help for making reservations. Per-night price including taxes and breakfast are ranging from 20 Euro (youth hostel, double room) to about 50 Euro (hotel, single room). ALCOM-FT will provides some grants for graduate students and young researchers. Priority will be given to applications of students and young researchers from ALCOM sites. CONTACT ------- The home page of ADFOCS with forms for registration and hotel reservation and information about grants can be found at http://www.mpi-sb.mpg.de/~adfocs For further information or questions, send an e-mail to adfocs@mpi-sb.mpg.de. ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From gershon at cs.utah.edu Fri Aug 9 11:21:05 2002 From: gershon at cs.utah.edu (Gershon Elber) Date: Mon Jan 9 13:41:07 2006 Subject: CFP - SM03 Message-ID: <200208091621.g79GL5015423@faith.cs.utah.edu> Dear comp. geom. fan Please consider the attached Call for Papers for the coming Solid Modeling 2003 meeting. We look forward to your sumbissions Sincerely Gershon Elber, Technion, Israel Vadim Shapiro, University of Wisconsin, USA Program Co-Chairs, ACM Solid Modeling 2003 ----------------------------------------------------------------------------- Call for Papers SOLID MODELING 2003 Eighth ACM Symposium on Solid Modeling and Applications University of Washington, Seattle, WA June 16-20, 2003 Sponsored by ACM SIGGRAPH The Solid Modeling symposia series is an international forum for the exchange of recent research and applications of solid modelling, shape modelling, and geometric computation in design, analysis and manufacturing, as well as in the emerging biomedical, geophysical and other areas. This highly successful symposium, which has been held bi-annually since 1991, brings together prominent researchers, key practitioners, and numerous students in the field. The symposium is held annually, alternating its location between the USA and other countries. The Solid Modeling 2003 symposium will be held on the campus of University of Washington in Seattle, WA, USA. In addition to technical papers in plenary sessions, the program for Solid Modeling 2003 will include: * academic and industrial tutorials * keynote lectures * panel and poster sessions * best paper award at the symposium banquet * sponsorship of students to attend the symposium * social program More information on the symposium can be found on the Solid Modeling 2003 web page: http://www.ce.washington.edu/sm03 The papers submission schedule is as follows: October 15, 2002: Abstracts due November 30, 2002: Full papers due February 10, 2003: Notice of acceptance and reviews March 31, 2003: Final camera-ready papers and extended abstracts due For details on how to submit abstracts and papers, please consult the web page http://www.ce.washington.edu/sm03/submit_proc. Abstracts are used to facilitate the review process and should be 150-300 words in length. Papers are limited to 12 typeset pages in length, including figures and references, and should present previously unpublished original results. All papers will be peer-reviewed and can be selected for presentation at a plenary session, or for presentation at a poster session, with publication in the conference proceedings published by ACM Press. A revised version of selected papers will also be published in special issues of related scientific journals. Best paper award will be selected by a jury of experts and will be presented at the symposium banquet. Symposium Co-Chairs: Pere Brunet, Polytechnical University of Catalonia, Barcelona, Spain George Turkiyyah, University of Washington, USA Program Co-Chairs: Gershon Elber, Technion, Israel Vadim Shapiro, University of Wisconsin, USA Industrial Chair: Jan Vandenbrande, Boeing Topics of interest for Solid Modeling 2003 include, but are not limited to: Geometric and topological representations Multi-resolution models Heterogeneous models Geometric interrogations and reasoning Computational geometry Robustness of geometric computations Blends, sweeps, offsets & deformations Procedural, constraint-based and parametric modeling Feature-based modeling Conceptual design techniques Product and assembly modeling Representation conversion Product data exchange User interaction techniques Haptic interfaces Collaborative/distributed design Virtual environments and prototypes Reverse engineering Engineering analysis using solid models Engineering tolerances Manufacturing and assembly planning Computational support for new manufacturing technologies Biomedical applications Geo-scientific applications Entertainment applications ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From exact at cs.nyu.edu Fri Aug 9 14:51:15 2002 From: exact at cs.nyu.edu (Chee Yap) Date: Mon Jan 9 13:41:07 2006 Subject: No subject Message-ID: <200208091751.g79HpFf13151@jinai.cs.nyu.edu> ===================== SOFTWARE RELEASE ANNOUNCEMENT ========================== August 10, 2002: Core Library Version 1.5 is now available for free download at http://cs.nyu.edu/exact/core/ The Core Library (CORE) is a collection of C/C++ classes to support computation with constructible real numbers (+,-,x,/,sqrt), under a variety of precision requirements. Numerical nonrobustness is a widely acknowledged problem. It has proven particularly intractable in the context of geometric algorithms where numerical data and combinatorial data are intermixed in a strongly constrained manner. Recent research in computational geometry has demonstrated a variety of techniques based on the principles of Exact Geometric Computation (EGC) that can address such problems. A basic goal of our library is to make such techniques easily accessible to the wider community of programmers and researchers. Basic CORE Features: -- ease of use: Any C/C++ programmer can write numerical or geometric code that are fully robust just by calling our Library. -- ease of migration: Many existing C/C++ programs can be converted into robust CORE programs with minimal effort. -- natural and novel numerical accuracy model: Users can choose and get the numerical accuracy that best fit their applications. -- state of art technology: The precision-driven approach to EGC, best known root bounds, filter technology, etc, will be incorporated into the library as the field progresses. In this way, the user's application program will automatically be upgraded (at the cost of re-compilation). -- small system: It can serve as the "robust core" of your own applications. About 550KB (including source, extensions, demos) when gmp and documentation is not included. Otherwise, the full distribution is 3.6MB. -- extensively tested on Sun Sparc, Linux, cygwin and Windows platforms. What is new with CORE 1.5 ? -- Faster code (can be significantly faster than CORE 1.4) -- Introduce headers for compiling CGAL with Core Library, made compatibility modifications, and sample CGAL programs -- Introduce namespace CORE -- Improved root bounds (can be significant) -- Improved Expression evaluation algorithms -- Streamlined code for Expr and Real (mainly through template classes) -- Level 2 and 4 programs can now be compiled (with limited support) -- Header files (i.e., API) for Expr and Real are mutually consistent (this was necessary to support Level 2 accuracy) -- More sample programs: (a) improved hypergeometric package (all the elementary functions in math.h are now available in Core) (b) polynomial package with Sturm sequences and Newton iteration for polynomail roots -- Compatibility with gmp 4.1, and g++ 3.1 -- Updated Core Library Tutorial -- Bug fixes: (a) bad initial root bound values for some constants (e.g., Expr(1.0)) (b) uMSB, lMSB (in Real, BigFloat, Filter classes) (c) BigInt::ceilLg We welcome your comments and input. -- Chee Yap (yap@cs.nyu.edu) Sylvain Pion (pion@cs.nyu.edu) Zilin Du (zilin@cs.nyu.edu) August 10, 2002 |============================================= | Exact Computation Project | Department of Computer Science | Courant Institute of Mathematical Sciences | New York University | 251 Mercer Street | New York, NY 10012, USA | | For further information: | http://cs.nyu.edu/exact/ | mailto://exact@cs.nyu.edu. | | Supported by NSF/ITR Grant CCR-0082056. |============================================= ===================== SOFTWARE RELEASE ANNOUNCEMENT ========================== ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From ayellet at ee.technion.ac.il Tue Aug 13 10:56:41 2002 From: ayellet at ee.technion.ac.il (Ayellet Tal) Date: Mon Jan 9 13:41:07 2006 Subject: CFP: ACM Symposium on Software Visualization Message-ID: <3D58ADA3.B83B0CA8@ee.technion.ac.il> ====================================================================== CALL FOR PAPERS ACM Symposium on Software Visualization SOFTVIS '03 June 11-13, 2003, San Diego, USA Collocated with FCRC'03 Sponsored by ACM SIGCHI, SIGGRAPH, SIGPLAN and SIGSOFT, and in cooperation with ACM SIGCSE. http://www.softvis.org/softvis03.html ====================================================================== Software visualization encompasses the development and evaluation of methods for graphically representing different aspects of software, including its structure, its abstract and concrete execution, and its evolution. The goal of this symposium is to provide a forum for researchers from different backgrounds (HCI, software engineering, programming languages, visualization, computer science education) to discuss and present original research on software visualization. SoftVis '03 is the first meeting in a planned series of biennial conferences. Our objective is to make the SoftVis series the premier venue for presenting all types of research on software visualization. Papers ====== We seek theoretical as well as practical papers on applications, techniques, tools and case studies. Topics of interest include, but are not restricted to, the following: - Visualization of algorithms, including numerical, geometric, genetic, distributed and graph algorithms - Program visualization - Protocol and log visualization (security, trust) - Visualization of parallel programs - Visualization in software engineering, e.g. UML diagrams - Visualization of the software development process - Visualization of data and processes in applications - Educational software in computer science, in particular visualization of computational models - Graph drawing algorithm for software visualization - Visualization of data base schemes - Visual debugging - 3D software visualization - Software visualization on the internet - Program analyses and visualization - Integration of software visualization tools and development environments - Empirical evaluation of software visualization system effectiveness Papers should represent original, unpublished results and will be rigorously reviewed by the international Program Committee. Papers must be in standard ACM 2-column format and cannot exceed 10 pages in total length. Authors should prepare and electronically submit a PDF version of their paper. Videos not exceeding 5 minutes in length can accompany a paper submission. Papers are due December 16, 2002. Further details on precise submission guidelines will be forthcoming. Tutorials ========= A set of tutorials will immediately precede the main conference. Tutorial proposals of no more than 1 or 2 pages (for 90-minute or 3-hour tutorials) should be submitted to the program chair by January 15, 2003. Include the proposed title, brief description of material, intended audience, assumed background of attendees, and the name, affiliation, contact information (e-mail and phone), and brief biography of speaker(s). An electronic PDF submission is preferred. Deadlines ========= Paper submission: December 16, 2002. Tutorial submission: January 15, 2003. Notification of acceptance: January, 27, 2003. Final papers due: March, 3, 2003 Student Travel ============== Conference Attendance Program for Students (CAPS) provides some financial support to graduate students, enabling them to attend SIGSOFT-sponsored conferences. Venue ===== SoftVis '03 is affiliated with the ACM Federated Computing Research Conference, a collection of symposia occurring June 7-14 in San Diego, CA. For more details on registration, hotel and travel information, please see the FCRC 2003 web pages (www.acm.org/sigs/conferences/fcrc/). Symposium Organizers ==================== General Chair: Stephan Diehl, Saarland University, Saarbr?cken, Germany Program Chair: John T. Stasko, Georgia Institute of Technology, Atlanta, USA Treasurer: Christopher D. Hundhausen, University of Hawai'i, Honolulu, USA Program Committee: Margaret Burnett, Oregon State University, USA Wim De Pauw, IBM Research, USA John Domingue, Open University, UK Steve Eick, Visintuit, USA Hideki Koike, University of Electro-Communications, Tokyo, Japan Eileen Kraemer, The University of Georgia, USA Hans Hagen, University Kaiserslautern, Germany John Hosking, University of Auckland, New Zealand Malcolm Munro, University of Durham, UK Petra Mutzel, Vienna University of Technology, Austria David Notkin, University of Washington, USA Tom Naps, University of Wisconsin-OshKosh, USA Marian Petre, Open University, UK Steve Reiss, Brown University, USA Margaret-Anne Storey, University of Victoria, Canada Erkki Sutinen, University of Joensuu, Finland Ayellet Tal, Technion, Israel Institute of Technology, Israel Reinhard Wilhelm, University of Saarland, Germany Andreas Zeller, University of Saarland, Germany More Information ================ For more information and questions about the SoftVis'03 Symposium, please send email to diehl@cs.uni-sb.de and stasko@cc.gatech.edu. ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From aupetit at dase.bruyeres.cea.fr Tue Aug 20 14:26:43 2002 From: aupetit at dase.bruyeres.cea.fr (aupetit) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... Message-ID: <200208201126.NAA00231@tupai.bruyeres.cea.fr> Hello, I need to compute the volume of a k-simplex knowing the coordinates of its vertices. How should I proceed? Any pointer? Thanks Michael ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From taubin at us.ibm.com Fri Aug 16 13:38:48 2002 From: taubin at us.ibm.com (Gabriel Taubin) Date: Mon Jan 9 13:41:07 2006 Subject: Analytic formulas for distance between geometric shapes. Message-ID: <200208161638.g7GGcmV44990@sp1n293en1.watson.ibm.com> > From: Dickinson, John > To: compgeom-discuss@research. bell-labs. com (E-mail) > Sent: Wednesday, July 24, 2002 11:29 AM > Subject: Analytic formulas for distance between geometric shapes. > > I am looking for analytic formulas for distance between basic > geometric shapes arbitrarily located and orientated in space.  Any > references (papers, books) would be greatly appreciated. > > The Sphere is the easy example as the distance between two spheres in > the distance between their centers minus the sum of their radii.  On > the other hand orientated boxes can't be done analytically but must be > done face by face. > > How about other shapes formed by implicit quadratic equations (eggs, > ovaloids, ...) that form not purely symmetric shapes which can be > orientated inspace. Do any of these shapes have analytic formulae for > distance? > > John > > -- > -((Insert standard disclaimer here))-|---  Ray's Rule for Precision ---- > John Kenneth Dickinson, Ph.D.        |   "Measure with micrometer; > Research Council Officer  IMTI-NRC   |    Mark with chalk; > email: john.dickinson@nrc.ca         |    Cut with axe." You may be interested in these two papers that I wrote quite a while ago. The problem was to decide which pixels are cut by an algebraic curve. The approach was based on good (fast, accurate, etc.) approximations to the distance from the center of the pixel to the curve (works for higher dimmensions too). The main problem was to make sure the singularities were properly dealt with. An Accurate Algorithm for Rasterizing Algebraic Curves and Surfaces, by G. Taubin. IEEE Computer Graphics & Applications, March 1994. Distance approximations for Rasterizing Implicit Curves, by G. Taubin. ACM Transactions on Graphics, January 1994 You can download the papers from the publications page in my IBM web site. You will also find a Java applet demo there that you can play with. --------------------------------------------------------------------- Dr. Gabriel Taubin taubin@computer.org IBM T. J. Watson Research Center taubin@us.ibm.com P.O.Box 704, Yorktown Heights, NY 10598 cell : (914)-217-7378 http://www.research.ibm.com/people/t/taubin phone: (914)-784-7095 fax : (914)-784-7667 --------------------------------------------------------------------- ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From wenger at cis.ohio-state.edu Fri Aug 16 09:26:20 2002 From: wenger at cis.ohio-state.edu (Rephael Wenger) Date: Mon Jan 9 13:41:07 2006 Subject: Software for isosurface table generation Message-ID: <15708.61292.571854.930628@beta.cis.ohio-state.edu> Isotable is a set of C++ classes and routines for generating isosurface patches in convex polyhedra in arbitrary dimensions. It constructs the isosurface patch as a subset of the convex hull of a subset of polyhedra vertices and edge midpoints. (See "Isosurfacing in higher Dimensions" by P. Bhaniramka, R. Wenger, and R. Crawfis, Visualization, 2000, Salt Lake City Utah: IEEE Computer Society Press.) Program genisotable generates isosurface lookup tables for hypercubes and simplices in arbitrary (small) dimensions. Isotable and genisotable source code is available at http://www.cis.ohio-state.edu/graphics/isotable. Source code includes K. Clarkson's program hull for generating convex hulls. ---------------- Dr. Rephael Wenger, Associate Professor, Ohio State U., Dept. of Comp. Sci., 2015 Neil Ave., Columbus, OH 43210-1277. tel: (614) 292-6253. e-mail: wenger@cis.ohio-state.edu ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From bradb at shore.net Tue Aug 20 22:04:54 2002 From: bradb at shore.net (Brad Barber) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... In-Reply-To: <200208201126.NAA00231@tupai.bruyeres.cea.fr> Message-ID: <4.3.2.7.2.20020820210006.01766ee8@mail.attbi.com> At 07:26 AM 8/20/2002, aupetit wrote: >Hello, > >I need to compute the volume of a k-simplex >knowing the coordinates of its vertices. You can compute the volume from the convex hull, This is practical up to about 8-d. For example, using Qhull DELL:/home/bbarber/cvswork/qhull3.2> rbox 200 D6 | qconvex FA Convex hull of 200 points in 6-d: Number of vertices: 155 Number of facets: 9280 Statistics for: rbox 200 D6 | qconvex FA Number of points processed: 175 Number of hyperplanes created: 36690 Number of distance tests for qhull: 71272 CPU seconds to compute hull (after input): 0.651 Total facet area: 2.6783254 Total volume: 0.23360794 --Brad http://www.geom.umn.edu/software/qhull [currently not responding] Spanish mirror: http://www6.uniovi.es/ftp/pub/mirrors/geom.umn.edu/software/ghindex.html >How should I proceed? >Any pointer? > >Thanks > >Michael > > >------------- >The compgeom mailing lists: see >http://netlib.bell-labs.com/netlib/compgeom/readme.html >or send mail to compgeom-request@research.bell-labs.com with the line: >send readme >Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From mount at cs.umd.edu Thu Aug 22 17:39:08 2002 From: mount at cs.umd.edu (Dave MOUNT) Date: Mon Jan 9 13:41:07 2006 Subject: SoCG'03 Call for Papers Message-ID: CALL FOR PAPERS, VIDEOS AND MULTIMEDIA 19th ACM Symposium on Computational Geometry http://www.cs.umd.edu/areas/Theory/socg/ June 8-10, 2003 - San Diego, USA In conjunction with FCRC 2003 Sponsored by ACM SIGACT and SIGGRAPH CALL FOR PAPERS --------------- The 19th ACM Symposium on Computational Geometry, featuring both theoretical and applied research, and a video review, will be held at the Town and Country Resort & Conference Center in San Diego (USA) as part of the Federated Computer Research Conference (FCRC 2003). We invite high-quality submissions in the following research areas: * Geometric algorithms and combinatorial geometry; * Implementation issues and applications of computational geometry. The accepted papers will be published in the symposium proceedings published by the ACM and distributed at the symposium. The proceedings will also be available separately for purchase from the ACM. A selection of papers from the conference will be invited to special issues of journals. There will be a prize for the best student-authored paper (see below). Research in computational geometry is very diverse, ranging from applied to theoretical, and the topics of the Symposium reflect this. Examples of more applied topics are: experimental analysis of algorithms and data structures; mathematical and numerical issues arising from implementations; and novel uses of computational geometry in other disciplines, such as robotics, computer graphics, geometric and solid modeling, manufacturing, geographical information systems, and molecular biology. Examples of more theoretical topics are: design and theoretical analysis of geometric algorithms and data structures; lower bounds for geometric problems; and discrete and combinatorial geometry. Paper Submission Electronic submissions are preferred, but authors may instead mail 8 copies of an extended abstract to arrive by December 5, 2002 to either of the two Program Co-Chairs Mark de Berg David Mount Dept. of Computer Science Dept. of Computer Science TU Eindhoven University of Maryland P.O.Box 513, 5600 MB Eindhoven College Park, MD 20742 the Netherlands USA markdb@cs.uu.nl mount@cs.umd.edu Important Dates Thu, December 5, 2002 Papers due Sat, February 15, 2003 Notification of acceptance or rejection of papers Sat, March 15, 2003 Camera-ready papers due June 8-10, 2003 Symposium Submission Guidelines Papers should be submitted in the form of an extended abstract, which begins with the title of the paper, each author's name, affiliation, and e-mail address, followed by a succinct statement of the problems and goals that are considered in the paper, the main results achieved, the significance of the work in the context of previous research, and a comparison to past research. The abstract should provide sufficient detail to allow the program committee to evaluate the validity, quality, and relevance of the contribution. The entire extended abstract should not exceed 10 pages, using 11 point or larger font and with at least one-inch margins all around. If the authors consider it absolutely essential to include additional technical details that do not fit into 10 pages, these details may be added in a clearly marked appendix that should appear after the body of the paper and the references; this appendix will not be regarded as a part of the submission and will be considered only at the program committee's discretion. Abstracts in hard copy must be received by December 5, 2002. Abstracts in electronic form are due by December 5, 5:00 PM EST; for further details please visit the conference webpage, http://www.cs.umd.edu/areas/Theory/socg/ These are firm deadlines; late submissions will not be considered. Authors will be notified of acceptance or rejection by February 15, 2003. A full version of each contribution in final form will be due by March 15, 2003 for inclusion in the proceedings. Best Student Paper Award A prize will be given to the author(s) of the best student-authored paper. The program committee may decline to make the award, or may split it among more than one paper. A paper is eligible if all of its authors are full-time students at the time of submission. This must be indicated during the electronic submission process, or, for hard copy submissions, in the cover letter. Conference Chair Steve Fortune (Bell Labs) Program Committee Mark de Berg, co-chair (TU Eindhoven) Prosenjit Bose (Carleton University) Erik Demaine (MIT) Tamal Dey (The Ohio State University) Olivier Devillers (INRIA Sophia Antipolis) Leo Guibas (Stanford University) Matthew Katz (Ben-Gurion University) Joe Mitchell (Stony Brook University) David Mount, co-chair (University of Maryland) Takeshi Tokuyama (Tohoku University) Gert Vegter (University of Groningen) Emo Welzl (ETH Zurich) CALL FOR VIDEOS AND MULTIMEDIA ------------------------------ Videos are sought for the 12th Annual Video Review of Computational Geometry. This video review showcases the use of visualization in computational geometry for exposition and education, as an interface and a debugging tool in software development, and for the visual exploration of geometry in research. Algorithm animations, visual explanations of structural theorems, descriptions of applications of computational geometry, and demonstrations of software systems are all appropriate. Videos that accompany papers submitted to the technical program committee are encouraged. This year the video review is experimenting with interpreting "video" broadly as any form of multimedia that can be rendered visually over time. In addition to the standard notion of videos (moving picture and sound), we allow submissions of PowerPoint animations, Java applets, and limited forms of other computed programs that generate video. These programs must have a "demo mode" that requires no interaction (after e.g. pressing a "demo" button) and demonstrates the program automatically. Audio can be generated by the program itself (e.g., PowerPoint animations can have a voice-over), or specified by a separate track. We prefer that such submissions are accompanied by standard videos, but when such preparation is difficult for the authors, the video rendering will be prepared by the video committee. All of these nonstandard arrangements must be coordinated with the video chair at least two weeks prior to submission. Accepted videos will be collected onto a DVD and distributed to attendees of the conference. The conference proceedings will include a submitted one- or two-page textual description of each video. In addition, authors will have the opportunity to give short presentations about accepted videos, how they were made, and brief background. These presentations will be interleaved with the showing of the videos during a video review session at the conference. Important Dates Fri, February 7, 2003 Video submissions due Fri, February 21, 2003 Notification of acceptance or rejection of videos Sat, March 15, 2003 Video abstracts due Fri, April 4, 2003 Final versions of videos due June 8-10, 2003 Symposium Video Submission Submissions are due by February 7, 2003. We strongly encourage electronic submission of videos. Electronic submissions should be in MPEG-2 format, although other arrangements can be made with the video chair. Specific requirements on encoding, instructions for preparing submissions, and methods of submission will be detailed soon on the webpage. Arrangements for nonelectronic submissions must be made at least two weeks prior to the deadline with the video chair. Each video must be accompanied by a one- or two-page description of the material shown in the video, and where applicable, the techniques used in the implementation. References to additional material describing the contents of the videos, such as accompanying papers, are encouraged. Please format the descriptions following the guidelines for ACM proceedings. The descriptions should be submitted electronically by e-mailing a PostScript or PDF file to the video chair. If electronic submission is impossible, authors should mail seven hardcopies of the description to the video chair: Erik Demaine MIT Laboratory for Computer Science 200 Technology Square Cambridge, Massachusetts 02139 USA Phone: (+1) 617-253-6871 Fax: (+1) 617-253-0415 edemaine@mit.edu Notification Authors will be notified of acceptance or rejection, and given reviewers' comments by February 21, 2003. For each accepted video, the final version of the textual description is due by March 15, 2003 for inclusion in the proceedings. Final versions of accepted videos are due by April 4, 2003. Video Program Committee Erik Demaine, chair (MIT) Fredo Durand (MIT) Steven Gortler (Harvard University) Piotr Indyk (MIT) Diane Souvaine (Tufts University) Seth Teller (MIT) Shang-Hua Teng (Boston University) ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From aupetit at dase.bruyeres.cea.fr Thu Aug 22 17:37:44 2002 From: aupetit at dase.bruyeres.cea.fr (aupetit) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... References: Message-ID: <200208221437.QAA19124@tupai.bruyeres.cea.fr> William Flis wrote: > > I need to compute the volume of a k-simplex > > knowing the coordinates of its vertices. > > For a triangle: > > Area = Abs(| 1 x1 y1 |) > | 1 x2 y2 | > | 1 x3 y3 | > ------------- > 2 > > For a tetrahedron: > > Volume = Abs(| 1 x1 y1 z1 |) > | 1 x2 y2 z2 | > | 1 x3 y3 z3 | > | 1 x4 y4 z4 | > ----------------- > 6 > > I believe this generalizes to any dimension k, with the denominator equal to > (k!). > > William J. Flis Director of Research > DE Technologies, Inc. > 3620 Horizon Drive > King of Prussia, PA 19406 > Voice: 610-270-9700 x130 > Fax: 610-270-9733 > mailto:flis@detk.com I forgot to mention that in my case the vertices of a k-simplex are given in R^n where n may be greater than k. I got this formula | det (W*W^t) | ^(1/2) Volume_k = ---------------------- k! on the site: http://www.math.washington.edu/~hillman/PUB/volume with W the matrix with k rows and n columns where W=(v_1-v_0) (v_2-v_0) ( ... ) (v_k-v_0) with row vectors v_i the k+1 vertices of the k-simplex in R^n. W^t denotes the transpose of W. Are both formulae equivalent when n=k? Thanks Michael -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20020822/5b59900e/attachment.htm From flis at detk.com Thu Aug 22 10:31:15 2002 From: flis at detk.com (William Flis) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... In-Reply-To: <200208201126.NAA00231@tupai.bruyeres.cea.fr> Message-ID: > I need to compute the volume of a k-simplex > knowing the coordinates of its vertices. For a triangle: Area = Abs(| 1 x1 y1 |) | 1 x2 y2 | | 1 x3 y3 | ------------- 2 For a tetrahedron: Volume = Abs(| 1 x1 y1 z1 |) | 1 x2 y2 z2 | | 1 x3 y3 z3 | | 1 x4 y4 z4 | ----------------- 6 I believe this generalizes to any dimension k, with the denominator equal to (k!). William J. Flis Director of Research DE Technologies, Inc. 3620 Horizon Drive King of Prussia, PA 19406 Voice: 610-270-9700 x130 Fax: 610-270-9733 mailto:flis@detk.com ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From hanwen at cs.uu.nl Thu Aug 22 19:48:53 2002 From: hanwen at cs.uu.nl (Han-Wen Nienhuys) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... In-Reply-To: <200208201126.NAA00231@tupai.bruyeres.cea.fr> References: <200208201126.NAA00231@tupai.bruyeres.cea.fr> Message-ID: <15717.5621.918258.366945@meddo.cs.uu.nl> aupetit@dase.bruyeres.cea.fr writes: > Hello, > > I need to compute the volume of a k-simplex > knowing the coordinates of its vertices. > > How should I proceed? > Any pointer? Assuming you're posing this is in k-dimensional space, that would be 1/(k!) * det (x_0, .. , x_k), where x_j is the k+1 - vector consisting of the k coordinates of the j-th point and a 1 as k+1st coordinate. -- Han-Wen Nienhuys | hanwen@cs.uu.nl | http://www.cs.uu.nl/~hanwen/ ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From jrs at buffy.EECS.Berkeley.EDU Fri Aug 23 16:32:30 2002 From: jrs at buffy.EECS.Berkeley.EDU (Jonathan Shewchuk) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... In-Reply-To: Your message of "Thu, 22 Aug 2002 16:37:44 +0200." <200208221437.QAA19124@tupai.bruyeres.cea.fr> Message-ID: <200208232232.PAA02407@buffy.EECS.Berkeley.EDU> > I got this formula > > | det (W*W^t) | ^(1/2) > Volume_k = ---------------------- > k! > > on the site: > http://www.math.washington.edu/~hillman/PUB/volume > > with W the matrix with k rows and n columns > where W=(v_1-v_0) > (v_2-v_0) > ( ... ) > (v_k-v_0) > > with row vectors v_i the k+1 vertices of the > k-simplex in R^n. > > W^t denotes the transpose of W. > > Are both formulae equivalent when n=k? Almost. When n = k, this formula is equivalent to the formulae William Flis and Han-Wen Nienhuys gave you--except that this formula always returns a positive volume, whereas the Flis and Nienhuys formulae gives you orientation information in the sign of the result (e.g. are the triangle's vertices in clockwise or counterclockwise order?). Note that when n = k, W is square, so | det (W*W^t) | ^(1/2) = det(W), and det(W) is obviously faster to compute than | det (W*W^t) | ^(1/2) (and gives you the orientation information). So for the special case n = k, I recommend using Volume_k = det(W) / k! Although the formulae are numerically equivalent up to sign, they are very different when floating-point roundoff error enters the picture. The Flis and Nienhuys formulae can have unnecessarily large errors, especially if the simplex is far from the origin. The formula on the Washington site (and the formula det(W) / k! when n = k) is numerically much better behaved. (If you care to know why, download my "Lecture Notes on Geometric Robustness" from http://www.cs.berkeley.edu/~jrs/mesh/ under Lecture 13, and read Section 2.) Jonathan Shewchuk UC Berkeley ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From hanwen at cs.uu.nl Fri Aug 23 16:14:29 2002 From: hanwen at cs.uu.nl (Han-Wen Nienhuys) Date: Mon Jan 9 13:41:07 2006 Subject: volume of a k-simplex... In-Reply-To: <200208221437.QAA19124@tupai.bruyeres.cea.fr> References: <200208221437.QAA19124@tupai.bruyeres.cea.fr> Message-ID: <15718.13621.139428.733086@meddo.cs.uu.nl> aupetit@dase.bruyeres.cea.fr writes: > | det (W*W^t) | ^(1/2) > Volume_k = ---------------------- > k! > > on the site: > http://www.math.washington.edu/~hillman/PUB/volume > > with W the matrix with k rows and n columns > where W=(v_1-v_0) > (v_2-v_0) > ( ... ) > (v_k-v_0) > > with row vectors v_i the k+1 vertices of the > k-simplex in R^n. > > W^t denotes the transpose of W. > > Are both formulae equivalent when n=k? Almost. When W has rank n, then det (W*W^T) = det(W)^2. The above formula always yields a positive answer. For an n-dimensional simplex, the determinant of the coordinate vectors can be negative depending on the orientation of the simplex. The formulation which uses a (k+1)x(k+1) determinant is more symmetric than the one that selects an origin vector (v_0 above) and uses the k x k determinant. I'm not sure if this has consequences for numerical precision and/or stability when using inexact computation. -- Han-Wen Nienhuys | hanwen@cs.uu.nl | http://www.cs.uu.nl/~hanwen/ ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From honestcox at excite.com Wed Aug 28 12:29:57 2002 From: honestcox at excite.com (Bradford Cox) Date: Mon Jan 9 13:41:07 2006 Subject: Inner offset Polygons Message-ID: <20020828152957.AB3651E48A@xmxpita.excite.com> Hello all, I am trying to solve a problem which is the calculation of an inner offset polygon based on a set of original points and a given offset distance. It is acceptable for the inner polygon to not be a "mirror" image of the original polygon since certain sides will converge to zero length, etc. Currently my focus has been in the area of straight skeletons. I intend on first creating a straight skeleton and then somehow generating the sides of the new inner polygon based on the the skeleton lines. (I am not sure how to do this just yet!) Does anyone have any suggestions for either the straight skeleton approach or some other approach? Thanks, Bradford Cox ------------------------------------------------ Changed your e-mail? Keep your contacts! Use this free e-mail change of address service from Return Path. Register now! -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20020828/d79fad19/attachment.htm From edemaine at mit.edu Thu Aug 29 12:23:30 2002 From: edemaine at mit.edu (Erik Demaine) Date: Mon Jan 9 13:41:07 2006 Subject: Inner offset Polygons In-Reply-To: <20020828152957.AB3651E48A@xmxpita.excite.com> Message-ID: Dear Bradford, Yes, if you want general orthogonal offsets, you'll need to compute the straight skeleton. Once you have the straight skeleton, it is not hard to compute offsets. It is useful to have extra combinatorial information about the straight skeleton: each skeleton edge is the bisector of two polygon edges, so you can store the two polygon edges next to each skeleton edge. Now, to compute an offset, pick a point on the straight skeleton of the appropriate distance to the appropriate edge, and construct parallels to the polygon edges and reflect whenever you hit an edge of the straight skeleton. There are existing implementations of the straight skeleton which you may want to use. I think this is a recent one: http://fractal.dam.fmph.uniba.sk/~sccg/proceedings/1998/Felkel.ps.gz Hope this helps, Erik -- Erik Demaine | edemaine@mit.edu | http://theory.lcs.mit.edu/~edemaine/ On Wed, 28 Aug 2002, Bradford Cox wrote: > Hello all, I am trying to solve a problem which is the calculation of an > inner offset polygon based on a set of original points and a given offset > distance. It is acceptable for the inner polygon to not be a "mirror" image > of the original polygon since certain sides will converge to zero length, > etc. Currently my focus has been in the area of straight skeletons. I intend > on first creating a straight skeleton and then somehow generating the sides > of the new inner polygon based on the the skeleton lines. (I am not sure how > to do this just yet!) Does anyone have any suggestions for either the > straight skeleton approach or some other approach? Thanks, Bradford Cox ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From blk at maia-institute.org Fri Aug 30 09:56:00 2002 From: blk at maia-institute.org (Brandon Kohn) Date: Mon Jan 9 13:41:07 2006 Subject: polygonization Message-ID: <001001c24ff2$4d16b950$0a00a8c0@maiainstitute.org> Hello all, I have a problem that I'm working on that requires an algorithm that will build polygons from an initial set of line segments in a 2D plane. This seems like the type of problem that has probably been solved optimally, but I haven't had much luck in finding any source code out on the net, or any good papers in the literature online. Could someone please point me in the proper direction? Thanks for any help ____________________________________________________________ Brandon Kohn Tel.: +377 97 97 41 51 Software Engineer/Sys Admin The Maia Institute Fax.: +377 97 97 41 59 Le Patio Palace 41, Avenue Hector Otto MC 98000 Monaco blk@maia-institute.org Important Notice This email and any attachments to it are confidential and intended solely for the individual(s) to whom they are addressed. Any modification or dissemination of the contents of this e-mail is strictly prohibited unless expressly authorized by the sender. If you receive this e-mail by mistake, please advise the sender immediately by using the reply facility in your e-mail software. Please also delete the message from your computer, and destroy any paper copies. Thank you for your co-operation. ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html.