From hoffkamp at inf.fu-berlin.de Wed Dec 1 16:44:09 2004 From: hoffkamp at inf.fu-berlin.de (Andrea Hoffkamp) Date: Mon Jan 9 13:41:17 2006 Subject: Postoctoral Position in the Graduate Program CGC Message-ID: <20041201153824.GB22926@inf.fu-berlin.de> ---------------------------------------------------------------------------- --- European Graduate Program "COMBINATORICS, GEOMETRY, AND COMPUTATION" --- ---------------------------------------------------------------------------- In the graduate program a postdoctoral position is available in Berlin for one year starting January 1, 2005 (or later) until December 31, 2005. The program is a joint initiative of the ETH Zurich, the three universities of Berlin - Free University, Technical University, Humboldt-University - and the Konrad-Zuse-Research Center. The German partners are financially supported by the German Research association (Deutsche Forschungsgemeinschaft, DFG). The amount of the scholarships in Berlin is calculated according to the guidelines of the DFG and is up to Euro 1468,- per month, tax free (family supplement Euro 205,-). The scientific program ranges from theoretical fundamentals to applications. The areas of research are combinatorics, geometry, optimization, algorithms and computation. In Berlin postdoctorands might join the groups of Aigner, Alt, Rote, Schulz (FU), Felsner, Moehring, Ziegler (TU), Proemel (HU), or Groetschel (TU and ZIB). Applications with curriculum vitae, copies of certificates, theses, a letter of recommendation, a brief description of the proposed research and reprints of publications should be sent until December 22, 2004 to the speaker of the program in Berlin: Prof. Dr. Helmut Alt Institut fuer Informatik Freie Universitaet Berlin Takustrasse 9 D-14195 Berlin or by email to: alt*at*inf.fu-berlin.de Further Information can be obtained from: Andrea Hoffkamp Tel. ++49-30-838 75 104 hoffkamp*at*inf.fu-berlin.de or by contacting one of the faculty members mentioned above. see also: http://www.inf.fu-berlin.de/gk-cgc --------------------------------------------------------------------------- ------------- 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 kettner at mpi-sb.mpg.de Thu Dec 2 13:17:41 2004 From: kettner at mpi-sb.mpg.de (Lutz Kettner) Date: Mon Jan 9 13:41:17 2006 Subject: EXACUS 0.9 Released, Efficient and Exact Algorithms for Curves and Surfaces Message-ID: We are pleased to announce the first public release 0.9 of EXACUS -- Efficient and Exact Algorithms for Curves and Surfaces -- containing a set of C++ libraries under an open source license: - ConiX Library (CnX): Provides conics in the plane, predicates on conics and their intersections, and computes the arrangement of conics in the plane, either based on our own sweep-line algorithm in the SweepX Library or based on the CGAL arrangements class for which we provide a traits class. - SweepX Library (SoX): Provides a generic sweep line algorithm to compute the planar arrangement of segments of algebraic curves. - NumeriX Library (NiX): Provides the algebraic and numerical foundations with number type support, polynomials, matrices, numerical and exact methods for solving polynomial equations, determinants, resultants, and more. - Library Support (LiS): Acts as a foundation layer and provides configuration, assertion, IO, memory management, generic algorithms, and other low level support for software libraries. We are also pleased to announce the release of the LEDA real Extended (EXT) implementation as part of the EXACUS project: - LEDA real Extended (EXT): An extended version of the LEDA real number type that contains the new diamond operator and improved separation bounds. The diamond operator introduces the exact computation with real roots of polynomials. The coefficients of the polynomial are not restricted to integers but can be of the EXT type itself. EXACUS is a project at the Algorithms and Complexity Group (AG1) at the Max-Planck-Institut f?r Informatik in Saarbr?cken, Germany, since 2001. For further information and for downloading the library, please visit: http://www.mpi-sb.mpg.de/EXACUS/ Best regards, Lutz Kettner ---------------------------------------------------------------------- Max-Planck-Institut fur Informatik email: kettner@mpi-sb.mpg.de Stuhlsatzenhausweg 85 phone: +49-681-9325-106 66123 Saarbrucken, Germany fax: +49-681-9325-199 ---------------------------------------------------------------------- ------------- 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 bsmolka at apricot.ia.polsl.gliwice.pl Thu Dec 2 15:07:15 2004 From: bsmolka at apricot.ia.polsl.gliwice.pl (Bogdan Smolka) Date: Mon Jan 9 13:41:17 2006 Subject: CFP - ICCS WORKSHOP: ADVANCED NONLINEAR TECHNIQUES OF COLOR IMAGE PROCESSING: THEORY AND APPLICATIONS Message-ID: <200412021422.iB2ELW4X019082@apricot.ia.polsl.gliwice.pl> Dear Colleagues, I would like to invite you to the International Conference on Computational Science (ICCS) to be held in Atlanta, US, May 22-25, 2005, http://conferences.mathcs.emory.edu/iccs2005/ and especially to the workshop: ?Advanced nonlinear techniques of color image processing: theory and applications?. The workshop is supposed to become a forum for discussions on the latest developments of color image processing and will focus on the theory applications of the advanced color based techniques. The special deadline for the participants of the Workshop is 03.01.2005. Please use the authors? toolkit provided by the ICCS organizers (http://conferences.mathcs.emory.edu/iccs2005/papers.html) and send your paper (max. 8 pages) in pdf format by e-mail to bsmolka@ia.polsl.gliwice.pl The accepted papers will be published by Springer in the Lecture Notes in Computer Science (LNCS) series. Looking forward to meeting you in Atlanta Best regards Dr Bogdan Smolka Silesian University of Technology 44-100 Gliwice, Poland bsmolka@ia.polsl.gliwice.pl -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20041202/8e111739/attachment.htm From bradb at shore.net Fri Dec 3 18:58:58 2004 From: bradb at shore.net (Brad Barber) Date: Mon Jan 9 13:41:17 2006 Subject: Is a halfspace intersection unbounded? Message-ID: <6.1.2.0.2.20041202205134.02575528@mail.comcast.net > A Qhull user asked the following question: Marcin Kuropatwinski: I am interested if the qhalf can provide information if the given halfspace intersection is bounded (has finite volume) or unbouded (infinite volume). In the options I did not found any hint. Do you know some solution to this problem? The dimension of the problem is 8, typical number of non-redundant halfspaces is 100-300 and number of extreme points 30000-300000. Qhull (qhalf) computes the halfspace intersection about a point by computing the convex hull of a dual transformation ["A simple case...", Preparata and Shamos, p. 316]. Does the computed convex hull distinguish between bounded and unbounded intersections? As a temporary solution I suggested adding a large bounding box to the input data. If the corresponding halfspaces are non-redundant, then the intersection is clearly bounded. This test does not distinguish a unbounded intersection from a large, but bounded intersection. Any suggestions for Marcin? --Brad -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20041203/28afd1e7/attachment.htm From fukuda at ifor.math.ethz.ch Sun Dec 5 19:58:17 2004 From: fukuda at ifor.math.ethz.ch (Komei Fukuda) Date: Mon Jan 9 13:41:17 2006 Subject: Is a halfspace intersection unbounded? In-Reply-To: <6.1.2.0.2.20041202205134.02575528@mail.comcast.net > References: <6.1.2.0.2.20041202205134.02575528@mail.comcast.net > Message-ID: <9F7BB75E-46EF-11D9-9ACD-000393913B90@ifor.math.ethz.ch> Hi, Checking whether a polyhedral region is bounded or not can be done by solving two linear programs (LPs). Let P = { x: A x = b, x >=0}, where A is a given m by d matrix and b is a m-vector. One can easily see P is unbounded <=> P is nonempty and there is a nonzero vector z such that A z = 0 and z >= 0. Let's assume P is nonempty (which can be checked by a single LP). Then, P is unbounded <=> there is a nonzero vector z such that A z = 0 and z >= 0 <=> there is no m-vector y such that y^T A > 0 (totally positive). The last equivalence is a variant of Farkas' Lemma. The last condition can be checked by solving an LP: max alpha (y^T A)_j >= alpha for all j=1,...,d and alpha <= 1. where alpha is a new variable. Clearly, this LP has a positive optimal value if and only if P is bounded. To deal with other forms of inequality sytems, e.g. P ={ x : A x <= b}, one can use standard techniques of inequality transformations. Because we only need to solve LPs, unboundedness can be recognized very fast for large d and m by both simplex-type methods and by interior-point methods. I hope this helps, Komei --- Komei Fukuda Institute for Operations Research and Institute of Theoretical Computer Science ETH Zentrum, CH-8092 Zurich, Switzerland Tel +41-1-632-4023, Fax +41-1-632-1025 http://www.ifor.math.ethz.ch/staff/fukuda/ On Dec 4, 2004, at 12:58 AM, Brad Barber wrote: > A Qhull user asked the following question: > > Marcin Kuropatwinski: > I am interested if the qhalf can provide information if the given > halfspace intersection is bounded (has finite volume) or unbouded > (infinite volume). In the options I did not found any hint. Do you > know some solution to this problem? The dimension of the problem is 8, > typical number of non-redundant halfspaces is 100-300 and number of > extreme points 30000-300000. > ? > Qhull (qhalf) computes the halfspace intersection about a point by > computing the convex hull of a dual transformation ["A simple > case...", Preparata and Shamos, p. 316].?? > > Does the computed convex hull distinguish between bounded and > unbounded intersections? > > As a temporary solution I suggested adding a large bounding box to > the input data.? If? the corresponding halfspaces are non-redundant, > then the intersection is clearly bounded.?? This test does not > distinguish a unbounded intersection from a large, but bounded > intersection. > > Any suggestions for Marcin? > > ????????????????????????????????????????--Brad > ------------- 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 fukuda at ifor.math.ethz.ch Sun Dec 5 20:30:17 2004 From: fukuda at ifor.math.ethz.ch (Komei Fukuda) Date: Mon Jan 9 13:41:17 2006 Subject: Is a halfspace intersection unbounded? Message-ID: <1813DD68-46F4-11D9-9ACD-000393913B90@ifor.math.ethz.ch> Just a side remark. > P is unbounded > <=> there is a nonzero vector z such that A z = 0 and z >= 0 > <=> there is no m-vector y such that y^T A > 0 (totally > positive). > > The last equivalence is a variant of Farkas' Lemma. > The last condition can be checked by solving an LP: > > max alpha > (y^T A)_j >= alpha for all j=1,...,d and > alpha <= 1. One can also use the following LP instead: max z_1 + z_2 + ... z_d subject to A z =0, z >=0 and z_j <= 1 for all j. If the LP has a positive optimal value, P is unbounded. In fact the optimal solution z* will be an unbounded direction. On the other hand, if the optimal value is zero, constructing a certificate for boundedness is a bit implicit in this method. Also, it is better to use an exact arithmetic to solve these LPs, as one needs to distinguish zero from any positive number correctly. Best, Komei ------------- 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 lewis at bway.net Mon Dec 6 15:03:23 2004 From: lewis at bway.net (Robert Lewis) Date: Mon Jan 9 13:41:17 2006 Subject: computational geometry proofs; systems of equations In-Reply-To: <1813DD68-46F4-11D9-9ACD-000393913B90@ifor.math.ethz.ch> References: <1813DD68-46F4-11D9-9ACD-000393913B90@ifor.math.ethz.ch> Message-ID: Hello, I am interested in establishing geometrical results (not necessarily theorems) by computer algebra, specifically via the solution of multivariate polynomial equations. I have used the Dixon resultant technique to do so, for example, Lewis, Robert H. and Stephen Bridgett, "Conic Tangency Equations and Apollonius Problems in Biochemistry and Pharmacology," Mathematics and Computers in Simulation 61(2) (2003) p. 101-114. pdf version here: www.bway.net/~lewis/lewbrid.pdf Some computational geometric proofs using a different technique are on the web site http://www.adeptscience.co.uk/maplearticles/f197.html. I wonder if anyone has tried (with such techniques) before to prove Ptolemy's theorem: For a quadalateral inscribed in a circle, let d1 and d2 be the (lengths of the) diagonals, d3 and d4 one pair of opposite sides, d5 and d6 the other. Then d1*d2 = d3*d4 + d5*d6. I have done so by getting 9 equations in the 6 di and 8 other variables that represent the sine and cosine of various angles. The resultant is indeed d1*d2 - d3*d4 - d5*d6. It takes about 40 minutes cpu time to do it. I have also proved the converse: assuming d1*d2 - d3*d4 - d5*d6 = 0, the quadralateral is on a circle. This actually takes far less time, about five minutes. Also, is there any information on similar three dimensional results? Regards, Robert H. Lewis Fordham University http://www.bway.net/~lewis/ ------------- 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 al001 at mail1.rrz.uni-koeln.de Mon Dec 6 20:59:33 2004 From: al001 at mail1.rrz.uni-koeln.de (Irwin Scollar) Date: Mon Jan 9 13:41:17 2006 Subject: non-convex hull Message-ID: <6.1.2.0.2.20041206204720.01fb3950@mail.rrz.uni-koeln.de> Given a set of random points in the plane, are there algorithms for finding the *non* convex hull of the set? If so, I'd appreciate any references as URL's if possible. A Google search didn't turn up anything useful. Irwin Scollar ------------- 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 hoffkamp at inf.fu-berlin.de Tue Dec 7 15:04:10 2004 From: hoffkamp at inf.fu-berlin.de (Andrea Hoffkamp) Date: Mon Jan 9 13:41:17 2006 Subject: Marie-Curie Scholarships for Ph.D. students Message-ID: <20041207140410.GA16570@inf.fu-berlin.de> ---------------------------------------- Marie-Curie-Scholarships ---------------------------------------- for Ph.D. students are available for a 3 to 12 month stay in Berlin. The starting date is flexible. In connection with our European Graduate Program "Combinatorics, Geometry, and Computation" we became a Marie Curie Training Site. We can support young researchers pursuing doctoral studies and providing them with the possibility of undertaking part of their doctoral studies in a country other than their own. Applicants must already have an advisor and a dissertation project in mathematics, computer science, or a related area at their home university. The Marie Curie Training Site is a joint initiative of the three universities of Berlin - Free University, Technical University, Humboldt- University - and the Konrad-Zuse-Research Center. The amount of the scholarship is 1200,00 Euro per month. The scientific program ranges from theoretical fundamentals to applications. The areas of research are combinatorics, geometry, optimization, algorithms and computation. During their stay the students are supervised by the professors Aigner, Alt, Rote, Schulz (FU), Felsner, Moehring, Ziegler (TU), Proemel (HU) and Groetschel (ZIB). Applications with curriculum vitae, copies of certificates, publications, a letter of recommendation of the advisor and a brief description of the status of the dissertation project should be sent until January 3, 2005 to: Prof. Dr. Helmut Alt Institut fuer Informatik Freie Universitaet Berlin Takustrasse 9 D-14195 Berlin or by email to: alt*at*inf.fu-berlin.de Further information can be obtained from: Andrea Hoffkamp: phone: ++49-30-838 75 104 e-mail: hoffkamp*at*inf.fu-berlin.de http://www.inf.fu-berlin.de/gk-cgc http://www.inf.fu-berlin.de/graduate-programs/cgc/ausschr-marie-curie.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 KieuTrong.Khanh at ait.ac.th Wed Dec 8 22:51:33 2004 From: KieuTrong.Khanh at ait.ac.th (Kieu Trong Khanh) Date: Mon Jan 9 13:41:17 2006 Subject: Range Tree algorithms Message-ID: <001e01c4dd3d$ce74c840$9c2d9fcb@ManhThuongQuan> Dear leader of computation geometry discuss group, I am implement project which relate with Range Searching! I download and implement with KD-Tree in Java. It is interesting and useful. However, I would like to improve with Range Tree algorithms. But Range Tree is more complex than KD-Tree! Therefore, I write this email with hoping you can give me a Range Tree algorithms (with multi dimention from 1 to n) implement in Java with input data is Point! Thanks! I know that Range Tree is improve from KD tree from Computation Gepmetry book. However, I is not good at Java. Therefore, I see many problems when implement! I am very sorry to disturb you! I hope your reply soon! With regards, Kha'nh -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20041208/8030cb1b/attachment.htm From hoffkamp at inf.fu-berlin.de Tue Dec 7 15:04:10 2004 From: hoffkamp at inf.fu-berlin.de (Andrea Hoffkamp) Date: Mon Jan 9 13:41:17 2006 Subject: [DMANET] Marie-Curie Scholarships for Ph.D. students Message-ID: <20041207140410.GA16570@inf.fu-berlin.de> ---------------------------------------- Marie-Curie-Scholarships ---------------------------------------- for Ph.D. students are available for a 3 to 12 month stay in Berlin. The starting date is flexible. In connection with our European Graduate Program "Combinatorics, Geometry, and Computation" we became a Marie Curie Training Site. We can support young researchers pursuing doctoral studies and providing them with the possibility of undertaking part of their doctoral studies in a country other than their own. Applicants must already have an advisor and a dissertation project in mathematics, computer science, or a related area at their home university. The Marie Curie Training Site is a joint initiative of the three universities of Berlin - Free University, Technical University, Humboldt- University - and the Konrad-Zuse-Research Center. The amount of the scholarship is 1200,00 Euro per month. The scientific program ranges from theoretical fundamentals to applications. The areas of research are combinatorics, geometry, optimization, algorithms and computation. During their stay the students are supervised by the professors Aigner, Alt, Rote, Schulz (FU), Felsner, Moehring, Ziegler (TU), Proemel (HU) and Groetschel (ZIB). Applications with curriculum vitae, copies of certificates, publications, a letter of recommendation of the advisor and a brief description of the status of the dissertation project should be sent until January 3, 2005 to: Prof. Dr. Helmut Alt Institut fuer Informatik Freie Universitaet Berlin Takustrasse 9 D-14195 Berlin or by email to: alt*at*inf.fu-berlin.de Further information can be obtained from: Andrea Hoffkamp: phone: ++49-30-838 75 104 e-mail: hoffkamp*at*inf.fu-berlin.de http://www.inf.fu-berlin.de/gk-cgc http://www.inf.fu-berlin.de/graduate-programs/cgc/ausschr-marie-curie.html ********************************************************** * * 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 mit2005 at vreme.yubc.net Thu Dec 9 02:27:32 2004 From: mit2005 at vreme.yubc.net (IPSI-2005 MIT and Belgrade) Date: Mon Jan 9 13:41:17 2006 Subject: Invitation to MIT and Belgrade 2005, c/ba Message-ID: <200412090127.iB91RWOE030040@vreme.yubc.net> Dear potential Speaker: On behalf of the organizing committee, I would like to extend a cordial invitation for you to attend one or both of the upcoming IPSI BgD multidisciplinary, interdisciplinary, and transdisciplinary conferences. The first one will be in Belgrade, Serbia and Montenegro: IPSI-2005 BELGRADE University of Belgrade (arrival: 2 June 05 / departure: 5 June 05) Deadlines: 1 March 05 (abstract) & 15 April 05 (full paper) The second one will be in Massachusetts, USA : IPSI-2005 USA Hotel@MIT, Cambridge (arrival: 7 July 05 / departure: 10 July 05) Deadlines: 20 February 05 (abstract) / 20 March 05 (full paper) All IPSI BgD conferences are non-profit. They bring together the elite of the world of science; so far, we have had seven Nobel Laureates speaking at the opening ceremonies. The conferences always take place in some of the most attractive places of the world. All those who come to IPSI conferences once, always love to come back (because of the unique professional quality and the extremely creative atmosphere); lists of past participants are on the web, as well as details of future conferences. These conferences are in line with the newest recommendations of the US National Science Foundation and of the EU research sponsoring agencies, to stress multidisciplinary, interdisciplinary, and transdisciplinary research (M.I.T. research). The speakers and activities at the conferences truly support this type of scientific interaction. Topics of interest include, but are not limited to: * Internet * Computer Science and Engineering * Mobile Communications/Computing for Science and Business * Management and Business Administration * Education * e-Medicine * e-Oriented Bio Engineering/Science and Molecular Engineering/Science * Environmental Protection * e-Economy * e-Law * Technology Based Art and Art to Inspire Technology Developments * Internet Psychology If you would like more information on either conference, please reply to this e-mail message. If you plan to submit an abstract and paper, please let us know immediately for planning purposes. Sincerely Yours, Prof. V. Milutinovic, Chairman IPSI BgD Conferences * * * CONTROLLING OUR E-MAILS TO YOU * * * If you would like to continue to be informed about future IPSI BgD conferences, please reply to this e-mail message with a subject line of SUBSCRIBE. If you would like to be removed from our mailing list, please reply to this e-mail message with a subject line of REMOVE. ------------- 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 nikola.nikolov at ul.ie Thu Dec 9 18:41:36 2004 From: nikola.nikolov at ul.ie (Nikola S. Nikolov) Date: Mon Jan 9 13:41:17 2006 Subject: GD2005: First Call for Papers Message-ID: <20041209074136.62A251341A7@nicta-atp-imss.nicta.com> Sender: Nikola S. Nikolov (nikola.nikolov@ul.ie) *** First Call for Papers *** GD2005 13th International Symposium on Graph Drawing September 12 - 14, 2005, Limerick, Ireland http://www.gd2005.org/ Graph Drawing is concerned with the geometric representation of graphs and networks and is motivated by those applications where it is crucial to visualize structural information as graphs. Bridging the gap between theoretical advances and implemented solutions is an important aspect of the conference. Indeed, advances in graph drawing are a key factor in such technological areas as Web computing, e-commerce, VLSI circuit design, information systems, software engineering, computational cartography, visual interfaces, bioinformatics, and networking. Researchers and practitioners working on theoretical and practical aspects of graph drawing are welcome to participate. Human performance studies based on perceptual and cognitive evaluations are encouraged. SCOPE The range of topics that are within the scope of the International Symposium on Graph Drawing includes (but is not limited to): * Visualization of networks, Web maps, software engineering diagrams, database schemas, chemical structures and molecules * Graph algorithms * Geometric graph theory and geometric computing * Software systems for graph visualization * Topology and planarity * Graph theory and optimization * Interfaces for interacting with graphs * Empirical assessment of graph drawing systems * Task analysis to guide graph drawing INVITED SPEAKERS Kurt Mehlhorn (Max-Planck-Institut fuer Informatik) George G. Robertson (Microsoft Research) CALL FOR PAPERS, DEMOS, AND POSTERS Authors are invited to submit papers describing original research and surveys of theoretical or practical significance to graph drawing. Demonstrations of systems incorporating original and innovative research ideas are also solicited. A system demonstration should include illustrative screen dumps and a description of the system's functionalities. Regular papers and demos must be labeled as either long or short; long papers will be assigned 12 pages in the conference proceedings, and short papers 6 pages. Submissions of posters in graph drawing and related areas are also solicited. The purpose is to provide a forum for the communication of results (which may appear elsewhere) to the graph drawing community. A poster will be given 2 pages in the conference proceedings. Submission of substantially similar papers or demos to GD 2005 and to other conferences with published proceedings is not allowed. INSTRUCTIONS FOR AUTHORS Each submission must include an indication of its type (paper, demo description, or poster) and contact information for the primary author. For a paper or a demo, an indication about whether it is a regular or a short submission must also be given. Electronic submissions are strongly encouraged. Detailed submission instructions will be provided on the conference web site. GRAPH DRAWING CONTEST Following the tradition of previous conferences, a graph drawing contest will be held. A $1,000 prize will be awarded to the winner. Details on the contest will be provided on the conference web site. IMPORTANT DATES * Submissions of papers, demos, and posters: May 31, 2005 * Notification of acceptance: July 15, 2005 * Graph Drawing Contest Submissions: September 5, 2005 PROCEEDINGS Accepted submissions will be published in the conference proceedings, which will be included in the Springer-Verlag series Lecture Notes in Computer Science. Final versions of accepted submissions are due at conference. RELATED EVENTS Workshop on Social Network Analysis and Visualisation, Sep 11, 2005. Workshop organizers: Seokhee Hong, Dorothea Wagner, and Ulrik Brandes. Please check the conference website for further details. LOCATION The International Symposium on Graph Drawing will be held at University of Limerick (UL) in Limerick, Ireland. UL is an independent, internationally focused university. Its campus, with the river Shannon at its centre, is located 5km from Limerick City and 20km from Shannon International Airport. Adjacent to the University is the National Technology Park Limerick (NTP). The tourist attractions near Limerick include the magnificent cliffs of Moher on the Atlantic coast and Bunratty castle. PROGRAM COMMITTEE Giuseppe Di Battista (Univ. di Roma III) Ulrik Brandes (University of Konstanz,) Peter Eades (NICTA, University of Sydney), co-chair Jean-Daniel Fekete (Inst. Nat. de Rech. en Informatique et en Automatique) Emden Gansner (AT&T Labs) Patrick Healy (University of Limerick), co-chair Seokhee Hong (NICTA, University of Sydney) Michael Kaufmann (University of Tuebingen) Jan Kratochvil (Charles Univer) Giuseppe Liotta (Universita degli Studi di Perugia) Kim Marriott (Monash University) Patrice de Mendez (Centre National de la Recherche Scientifique) Petra Mutzel (Vienna University of Technology) Janos Pach (City College and Courant Institute) Helen Purchase (University of Glasgow) Md. Saidur Rahman (Bangladesh University of Engineering and Technology) Ben Shneiderman (University of Maryland) Ondrej Sykora (Loughborough University) Sue Whitesides (McGill University) Steve Wismath (University of Lethbridge) David Wood (McGill University) ORGANIZING COMMITTEE Patrick Healy (University of Limerick), co-chair Stephen Kobourov (University of Arizona) Karol Lynch (University of Limerick,) Joseph Manning (University College Cork) Nikola S. Nikolov (NICTA, University of Limerick), chair Aaron Quigley (University College Dublin) Gemma Swift (University of Limerick) Alexandre Tarassov (University of Limerick) CONTEST COMMITTEE Christian Duncan (University of Miami) Stephen Kobourov (University of Arizona), chair Dorothea Wagner (University of Karlsruhe) CONTACT INFORMATION The symposium's website is available at http://www.gd2005.org. The organizing committee can be contacted at gd2005@ul.ie. Nikola Nikolov IMAGEN Program, NICTA, Bay 15 Locomotive Workshop, Australian Technology Park, Eveleigh NSW 1430, AUSTRALIA Phone: +61 2 8374 5474, Fax: +61 2 8374 5527 E-mail: nikola.nikolov@nicta.com.au Patrick Healy CSIS Department, University of Limerick, Limerick, IRELAND Phone: +353 61 202 727, Fax: +353 61 202 734 E-mail: patrick.healy@ul.ie -------------- next part -------------- A non-text attachment was scrubbed... Name: gd2005cfp01.pdf Type: application/pdf Size: 28153 bytes Desc: not available Url : http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20041209/4c6e378b/gd2005cfp01.pdf From wrf at ecse.rpi.edu Thu Dec 9 16:53:51 2004 From: wrf at ecse.rpi.edu (W. Randolph Franklin) Date: Mon Jan 9 13:41:17 2006 Subject: grad RA or postdoc available in Computational Geometry/Cartography Message-ID: <200412092153.QAA25927@ra.ecse.rpi.edu> RESEARCH ASSISTANTSHIP or POSTDOC available starting Jan 2005 Geologically Correct Terrain Data Structures & Radar Siting W. Randolph Franklin Rensselaer Polytechnic Institute wrf@ecse.rpi.edu, http://wrfranklin.org/ This new DARPA project requires researchers to help us advance terrain representation and terrain analysis. New representations for terrain are necessary for two reasons. First, the growing volume of data from LIDAR and IFSAR requires new techniques. (A 1-meter grid over the Earth requires $10^{14}$ postings.) Second, all the existing techniques have severe shortcomings. The most important from the user's viewpoint is that existing techniques make it easy to represent impossible terrain, but impossible to represent certain legal and common terrain, such as cliffs. Our longest-term idea is to avoid weaknesses in current terrain representation techniques by representing terrain with a new morphological terraforming operator called scooping. The resulting terrain is much more realistic than terrain generated by, e.g., a Fourier expansion. The second component of this proposed terrain research addresses the problem of interpolating terrain from a set of data points using an overdetermined Laplacian PDE. The third terrain representation technique is a Triangulated Irregular Network (TIN). TINs have been widely used since Franklin's first implementation of a TIN in cartography back in 1973. Because of the large quantity of terrain elevations produced, e.g., by the SRTM, data compression is necessary. The compression should be lossy, because the original data is not perfect and also because of the considerably greater efficiency of lossy compression relative to lossless. When evaluating the quality of a compression, application domain specific metrics are appropriate. The first terrain analysis component of this project concerns efficient include multi-observer siting; see the poster outside my office (JEC6026). Drainage net computation is the next terrain operation. In principle, depositing the desired quantity of rain on each point of the terrain cell, and then allowing it to flow to that point's lowest neighbor, looks easy. The reality is different. ------------------- Consult my papers and talks on my website for more info on the topic. Desirable skills include Math, CS, writing, programming in C++, linux, GIS, and cartography. Both RPI students, and others (currently in the US) willing to transfer to RPI are welcome to apply. Email your application, in plain text or PDF. Show how your background qualifies you. Start the subject with 'RA Application'. ---- ------------- 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 KieuTrong.Khanh at ait.ac.th Sun Dec 12 07:25:49 2004 From: KieuTrong.Khanh at ait.ac.th (Kieu Trong Khanh) Date: Mon Jan 9 13:41:17 2006 Subject: Range Tree algorithms Message-ID: <001201c4dfe1$292fca50$9c2d9fcb@ManhThuongQuan> I am implement project which relate with Range Searching! I download and implement with KD-Tree in Java. It is interesting and useful. However, I would like to improve with Range Tree algorithms. But Range Tree is more complex than KD-Tree! Therefore, I write this email with hoping you can give me a Range Tree algorithms (with multi dimention from 1 to n) implement in Java with input data is Point! Thanks! I know that Range Tree is improve from KD tree from Computation Gepmetry book. However, I is not good at Java. Therefore, I see many problems when implement! I am very sorry to disturb you! I hope your reply soon! With regards, Kha'nh -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20041212/73c599da/attachment.htm From bradb at shore.net Sun Dec 12 17:57:42 2004 From: bradb at shore.net (Brad Barber) Date: Mon Jan 9 13:41:17 2006 Subject: Is a halfspace intersection unbounded? In-Reply-To: <9F7BB75E-46EF-11D9-9ACD-000393913B90@ifor.math.ethz.ch> References: <6.1.2.0.2.20041202205134.02575528@mail.comcast.net > <9F7BB75E-46EF-11D9-9ACD-000393913B90@ifor.math.ethz.ch> Message-ID: <6.1.2.0.2.20041212173246.02341ec0@mail.comcast.net > [With Steven Spitz] Qhull computes halfspace intersection about a point by computing the convex hull of the dual vertices. Halfspaces at distance d from the origin are dual to vertices at distance 1/d. So the bounding box at infinity is equivalent to the origin. If the origin is inside the dual polytope, then the original polytope is bounded. Otherwise it is either unbounded. So in Qhull, boundedness is equivalent to every inner plane (option 'Fi') having a negative offset (the inner planes are clearly inside the dual polytope). Unboundedness is equivalent to at least one outer plane (option 'Fo') having a positive offset. If you do not need halfspace intersections, then Komei's LP solution is best. --Brad ------------- 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 sve2005 at MIRALAB.UNIGE.CH Tue Dec 14 08:27:25 2004 From: sve2005 at MIRALAB.UNIGE.CH (Semantic Virtual Environments 2005) Date: Mon Jan 9 13:41:18 2006 Subject: 1st CfP - Semantic Virtual Environments (SVE) 2005 Message-ID: <41BE95DD.8070309@miralab.unige.ch> [Apologies if you receive this CFP more than once] >>Workshop on Semantic Virtual Environments' 2005 >SVE 2005 >>Organized by >MIRAlab, University of Geneva (www.miralab.unige.ch) and >CUSO (www.cuso.ch) with the support of the AIM@Shape European Network of Excellence (www.aimatshape.net) >>2005 March 16, 17 & 18 >>Villars, CH IMPORTANT DEAD-LINE: Original research paper/State-of-the art reports: January 30, 2005 >Virtual shapes are 3D digital representations of either physically existing objects or virtual objects that can be processed by computer applications. Virtual shapes occur and are used in many different environments such as: Industrial Design (e.g., CAD models of products, laser-scanned prototypes), Medical Applications (e.g., biomedical simulation) or Edutainment and training (e.g., computer animations, virtual humans). >Until recently, digital 3D shape representations were mainly limited to the acquisition and the modeling of their geometry and visual properties. However, shapes are not restricted to geometry but also include knowledge data. New avenues of research are now emerging to shift from a geometric to a semantic-aware level of representation of digital shapes. >The objective of this workshop is evaluating and depicting the current state of the art in semantic-based shape representations and semantic-oriented methods to acquire, build, transmit, and process shapes with their associated knowledge. A particular attention will be addressed to the semantic representation and simulation of virtual humans as they are especially representative of digital shapes integrating a high dimension of associated knowledge. >Semantic-based shape representations are closely related to current emerging standards such as the MPEG ones, and particularly MPEG-7 and MPEG-21. Moreover, digital shapes are expected to take a central role in the Semantic Web in the next years, with high potential impact in several key areas. >The workshop includes presentation of original research papers, state-of-the art reports and panel discussions. >>Submission deadlines are; - Original research paper/State-of-the art reports: January 30, 2005 - Panel proposal: February 20, 2005 -Submissions of full papers (8 to 10 A4 pages) are invited for oral presentation and publication in the workshop proceedings. -Paper templates, format and submissions guidelines are available at http://www.miralab.unige.ch/sve2005/ Topics of interest in the scope of the workshop include but are not limited to >Optimized Systems for Shape Acquisition and Reconstruction >Shape Reconstruction from Images >Point Cloud Matching >Human Shape Reconstruction >Geometry Processing for the Semantics >Multi-Resolution Representations >Statistical Learning Techniques for Shape Characterization and Feature Detection >Skeletal Structures and Critical Characteristics for Shape Representation >Multi-Scale Models for Shape Representation >Semantics and Shape for Industrial Design >Incorporating Semantics and Ontologies in Product Development and Simulation >Semantics of Virtual Humans >Visual Shape Entropy >Standards for Shapes Representation >>Workshop Co-Chairs Nadia Magnenat-Thalmann, University of Geneva, CH Daniel Thalmann, EPFL, Lausanne, CH >>Program Co-Chairs Bianca Falcidieno, CNR-IMATI, Genova, IT Nadia Magnenat-Thalmann, University of Geneva, CH >>Program Committee (tentative) M. Alexa, TU Darmstadt, DE P. Alliez, INRIA, Sophia-Antipolis, FR D. Attali, INPG, Grenoble, FR M. Attene, CNR-IMATI, Genova, IT G. Barequet, Technion-Israel Institute of Technology, IL R. Basri, Weizmann Institute of Science, IL A. Belyaev, Max-Planck Institute, DE S. Biasiotti, CNR-IMATI, Genova, IT V. Blanz, Max-Planck Institute, DE G. Brunetti, FjG/IGD, DE M-P Cani, INPG, Grenoble, FR D. Cohen-Or, Tel Aviv University, IL L. De Floriani, Universty of Genova, IT G. Elber, Technion-Israel Institute of Technology, IL B. Falcidieno, CNR-IMATI, Genova, IT F. Giannini, CNR-IMATI, Genova, IT C. Gostman, Technion-Israel Institute of Technology, IL J. Haber, Max-Planck Institute, DE S. Hahmann, INPG, Grenoble, FR H. Kim, University of Geneva, CH L. Kobbelt, RWTH-Aachen , DE J-C Leon, INPG, Grenoble, FR B. Levy, INRIA, Sophia-Antipolis, FR N. Magnenat-Thalmann, University of Geneva, CH P. Min, Utrecht University, NL L. Moccozet, University of Geneva, CH M. Mortara, CNR-IMATI, Genova, IT B. Mourrain, INRIA, Sophia-Antipolis, FR J-O Nygaard, SINTEF, Oslo, NO E. Puppo, Universty of Genova, IT E. Quak, SINTEF, Oslo, NO H-P Seidel, Max-Planck Institute, DE M. Spagnuolo, CNR-IMATI, Genova, IT A. Stork, FjG/IGD, DE A. Tal, Technion-Israel Institute of Technology, IL D. Thalmann, EPF Lausanne, CH R. Veltkamp, Utrecht University, NL A. Verri, Universty of Genova, IT F. Vexo, EPF Lausanne, CH >>Local Committee HyungSeok Kim, University of Geneva, CH Laurent Moccozet, University of Geneva, CH For more information, please consult following web sites: General information on the workshop: http://sve2005.miralab.unige.ch/ >>Contact: sve2005@miralab.unige.ch ------------- 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 speckman at win.tue.nl Wed Dec 15 18:20:30 2004 From: speckman at win.tue.nl (Bettina Speckmann) Date: Mon Jan 9 13:41:18 2006 Subject: Spring school on Computational Geometry Message-ID: <41C0725E.7040106@win.tue.nl> Spring school on Computational Geometry A spring school on Computational Geometry wil be organized at the Technische Universiteit Eindhoven on March 7-8, 2005. The school is followed by the 21st European Workshop on Computational Geometry on March 9-11, 2005. Workshop/Spring school website http://www.win.tue.nl/EWCG2005/ The target audience for this spring school are PhD students and postdocs that work in the area of computational geometry and/or in algorithm design and analysis. The program of the school is divided into four blocks (two per day) which are each devoted to a specific topic. Each block consists of lectures and problem solving exercises in small groups. Since we can only accommodate a limited number of participants please send an (electronic) application with a short description of your research interests and your previous knowledge in the areas addressed by the school to Mark de Berg (m.t.d.berg@tue.nl). Applications will be accepted as of now. Spots will be filled on a "first-come-first-serve" basis so we recommend to apply early. The registration fee includes all materials as well as lunches and coffee breaks during the spring school. Invited Speakers: Lars Arge, University of Aarhus, I/O Efficient Algorithms Danny Halperin, Tel Aviv University, Arrangements Sariel Har-Peled, Univ. of Illinois at Urbana-Champaign, Core Sets Marc van Kreveld, Utrecht University, Algorithms for GIS Application Deadline: February 7, 2005 Spring School Dates: March 7-8, 2005 Registration fee: 50 ? ------------- 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 ewcg2005 at win.tue.nl Wed Dec 15 18:13:22 2004 From: ewcg2005 at win.tue.nl (European Workshop on Computational Geometry 2005) Date: Mon Jan 9 13:41:18 2006 Subject: EWCG 2005 - 2nd call for papers Message-ID: <41C070B2.4000808@win.tue.nl> 2nd CALL FOR PAPERS The 21st European Workshop on Computational Geometry The 21st European Workshop on Computational Geometry will take place on March 9-11, 2005, at the Technische Universiteit Eindhoven. The workshop will be preceded by a Spring School on March 7-8, 2005. Workshop/Spring school website http://www.win.tue.nl/EWCG2005/ Workshop ------------ The goal of this annual, informal workshop is to provide an opportunity for established researchers from academia, R&D people from industry, research students, and postdocs to meet and present their current work in order to further scientific interaction and international collaboration. Topics of interest include, but are not restricted to: * Analysis of geometric algorithm design and data structures including theoretical issues arising from implementations, geometric optimization, combinatorial geometry, and analysis of geometric configurations. * Applications of computational geometry in robotics and virtual worlds, computer graphics, simulation and visualization, image processing, geometric and solid modeling, computer aided geometric design, manufacturing, geographical information systems, and structural molecular biology. Important Dates: Submission: January 10, 2005 Program available: January 24, 2005 Early registration: February 7, 2005 Workshop dates: March 9-11, 2005 ------------- 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 xgao at mmrc.iss.ac.cn Wed Dec 22 16:45:59 2004 From: xgao at mmrc.iss.ac.cn (Xiaoshan GAO) Date: Mon Jan 9 13:41:18 2006 Subject: CFP: Message-ID: <200412220845.iBM8jxY5001490@mmrc.iss.ac.cn> Apologize if you receive multiple copies _____________________________________________________________ CFP: Geometric Constraints A special issue of International Journal of Computational Geometry and Applications _____________________________________________________________ Geometric Constraints Solvers are today a key component of all geometric modelers. Geometric constraints occur for dimensioning and tolerancing mechanical parts in CAD-CAM, for modeling curves, surfaces and blends, for conception of mechanisms, for finding the configurations of robots in robotics or of molecules in chemistry. New applications of constraints modeling will likely arise. In recent years, research on geometry constraint solving is quite active. Besides many reports in large scale conferences, geometry constraint solving is one of the main themes of several specialized workshops including the ISICAD workshop held in Russia in June 2004, the ADG workshop held in USA in September 2004, and the Workshop on Geometric Constraint Solving held in China in October 2003. We feel that it is time to publish a special issue devoted to this important topic. Thus IJCGA is devoting a special issue to the subject of geometric constraints. Authors should note the benefits of publication in a special issue - a collection of high-quality related papers in one volume, with expedited handling of the review and revision of accepted papers. The journal has committed to giving priority in the publication queue for the special issue. Manuscripts are solicited on topics to include: -resolution of geometric constraints, with computer algebra, numerical analysis, interval analysis, logical approaches (e.g. provers), or other methods, -decomposition of systems of geometric constraints, -mixing geometric and non geometric constraints, white boxes, black boxes, geometric constraints and constraints programming, -detection of dependence between constraints, debugging geometric constraints, -constrained curves, surfaces, blends, -exotic (eg non cartesian) formulations of constraints, -comparison of resolution methods or constraints formulations for the same problems, -mathematical background: combinatorial rigidity, graph theory, matroid theory, computer algebra (polynomial systems, dimension of ideals), -detailed applications, in Computer Graphics, CAD-CAM, robotics, mechanism design, chemistry (eg molecule configurations), photogrammetry, virtual reality, -sensitivity to value parameters, and other robustness issues, -choice of the "good" solution, -dynamic geometry, -computer-human interfaces for geometric constraints, -geometric constraints and data exchange, -topological constraints, eg optimal curves or surfaces with prescribed, topology (homology, homotopy, isotopy), -shape optimization, -geometric constraints and geometric representations (boundary representation, constructive solid geometry, features), -integration of geometric solvers into modelers, -solvers architecture, -geometric solver industrial/market solutions. Authors should send their submission as a file attachment in pdf or postscript format to both guests editors by June 12, 2005. Xiao-Shan Gao Institute of Systems Science, Academia Sinica, Beijing 100080 China Email: xgao@mmrc.iss.ac.cn http://www.mmrc.iss.ac.cn/~xgao Tel: 86-10-6254-1831 Fax: 86-10-6263-0706 Dominique Michelucci Laboratory Electroninics, Computer Science, Image Faculty sciences & techniques University of Burgundy BP 47870 21078 Dijon Cedex France Email: Dominique.Michelucci@u-bourgogne.fr Tel: 333.80.39.38.85 from abroad, 03.80.39.38.85 from France Fax: 333.80.39.59.10 from abroad, 03.80.39.38.85 from France While submissions may be in any standard format, accepted papers will need to be prepared using latex, following the journal guidelines available at http://www.worldscinet.com/journals/ijcga/mkt/guidelines.shtml and http://www.worldscinet.com/authors/stylefiles.shtml Authors are encouraged to submit as early as possible. All manuscripts will be promptly and carefully refereed. ------------- 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 Andreas.Fabri at geometryfactory.com Wed Dec 22 20:18:13 2004 From: Andreas.Fabri at geometryfactory.com (Andreas Fabri) Date: Mon Jan 9 13:41:18 2006 Subject: CGAL 3.1 Released, Computational Geometry Algorithms Library Message-ID: <41C9C875.7030200@geometryfactory.com> We are pleased to announce the release 3.1 of CGAL, the Computational Geometry Algorithms Library. Besides improvements of existing packages this release offers the following new algorithms and data structures. o 2D Segment Voronoi Diagram An incremental algorithm for Voronoi diagrams of segments in the plane under the Euclidean metric. The Voronoi edges are arcs of straight lines and parabolas. In case the input segments intersect, the Voronoi diagram of their arrangement is computed. o 2D Conforming Triangulations and Meshes An implementation of Shewchuk's algorithm to construct conforming triangulations and 2D meshes. o 3D Boolean Operations on Nef Polyhedra A data structure representing 3D Nef polyhedra, a boundary representation for cell-complexes bounded by halfspaces that supports Boolean operations and topological operations in full generality including unbounded cells, mixed dimensional cells (e.g., isolated vertices and antennas). Nef polyhedra distinguish between open and closed sets and can represent non-manifold geometry. Also available are planar Nef polyhedra embedded on the sphere. o dD Box Intersection Testing and Reporting A new efficient algorithm for finding all intersecting pairs for large numbers of iso-oriented boxes. Typically these will be bounding boxes of more complicated geometries. Useful for (self-) intersection tests of surfaces etc. o 2D Snap Rounding An algorithm for converting arbitrary-precision arrangements of segments into a fixed-precision representation. An Iterated Snap Rounding algorithm is also available in which each vertex is at least half the width of a pixel away from any non-incident edge. o 2D and Surface Function Interpolation Several algorithms for scattered data interpolation from measures of a function on a set of discrete data points. The package further offers functions for natural neighbor interpolation. See http://www.cgal.org/releases_frame.html for a complete list of changes. The CGAL project is a collaborative effort to develop a robust, easy-to-use, and efficient C++ software library of geometric data structures and algorithms. The CGAL library contains: o The Kernel providing basic geometric primitives such as points, vectors, lines, predicates for testing things such as relative positions of points, and operations such as intersections and distance calculation. o The Basic Library, a collection of standard data structures and geometric algorithms, such as convex hull, (Delaunay, Regular, Constrained) triangulation, Voronoi diagrams, planar map, arrangements, polyhedron, smallest enclosing sphere, multidimensional query structures... o Interfaces to other packages, e.g. for visualization, and I/O, and other support facilities. The Kernel is distributed under the terms of the LGPL Open Source license (GNU Lesser General Public License v2.1). The Basic Library is distributed under the terms of the QPL Open Source license (Q Public License v1.0). If your intended usage does not meet the criteria of the aforementioned licenses, a commercial license must be purchased from GeometryFactory (www.geometryfactory.com). For further information and for downloading the library and its documentation, please visit the CGAL web page: http://www.cgal.org/ ------------- 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.