February 26, 2007: The thorn LSUPETSc implements a generic elliptic solver for Carpet's multi-patch infrastructure, based on PETSc. It assumes touching (not overlapping) patches, and uses inter-patch interface conditions very similar to those developed by Harald Pfeiffer. LSUPETSc can solve "arbitrary" systems of coupled, non-linear elliptic equations. It does not support mesh refinement.
January 12, 2007: In order to be able to restructure some of Carpet's internals without disturbing ongoing production simulations, we have created an experimental version. The main goals of this experimental version are to improve its performance on many (>100) processors and to re-arrange some internal details to simplify future development. Few new features are planned, but some of the changes may be incompatible.
December 15, 2006: The AEI hosted a small workshop to improve the performance of the AEI/LSU CCATIE code for binary black hole simulations, which uses Carpet as AMR driver. We examined especially the effect of various grid structures on accuracy and speed and speeded up the wave extraction routine. We were able to improve the overall performance of the code by a factor of six for a certain benchmark problem simulating a QC-0 configuration.
September 26, 2006: We are preparing a new release of Carpet. This will be Carpet version 3. Among other things, this version makes it easier to use dynamic grid structures, shows better scaling behaviour than version 2, and has better support for multiple patches. A detailed list of changes is here. The the downloading instructions for Carpet explain how to access this version.
February 26, 2006: We have started to collect a list of publications and theses that use Carpet. Please tell us if you have written a publication or a thesis using Carpet.
February 25, 2006: Christian Ott has contributed code to Carpet, making the refined regions track apparent horizon centroids, merging and un-merging refined regions as necessary. (Movie, animated gif, 730 kB.) After Burkhard Zink's mechanism which tracks the density maximum in a star, this is the second implementation of a production level adaptive mesh refinement criterion in Carpet.
February 25, 2006: The official Cactus benchmarks now include benchmarks with Carpet. You can assess Carpet's scaling and compare its performance on different machines by generating graphs from the benchmark result database on these pages.
July 15, 2005: We have now a page that links to all past montly status reports.
June 6, 2005: We have updated the downloading instructions for Carpet.
June 6, 2005: Version 1.0.3 of the pre-compiled darcs binary is now available.
April 13, 2005: Thomas Radke has implemented a new communication scheme in Carpet. Instead of sending many small messages in an interleaved manner, Carpet now collects all messages into an internal buffer and sends only one big message with MPI. This circumvents certain problems with internal limitations of MPICH, and it also improves the performance greatly.
March 9, 2005: We have started to move towards a new stable version of Carpet.
December 7, 2004: Jonathan Thornburg is organising a Carpet Design Walkthrough, which will take place December 13 to 15 at the AEI and will be broadcast via the accessgrid and/or telephone.
Sepbember 18, 2004: There is now a new repository for the development version of Carpet. This repository is managed by darcs instead of CVS. Darcs has a number of advantages, such as being able to use it while offline, or keeping some changes to yourself while developing. This development version is publicly available, and we encourage you to contribute. Note that the stable version of Carpet is still distributed via CVS.
August 24, 2004: The version of Carpet in the CVS repository is now stable. That means that this version will see no substantial further development. One of its main goal is to not change, so that parameter files continue to work unchanged with identical results. We will continue to correct errors that we find in this version of Carpet; however, if this would necessitate major changes, and there is a work-around, then this might not happen in the interest of stability.
July 31, 2004: Carpet seems to have reached a point where it is stable enough to be useful for at least some projects. Consequently, people expressed the wish to have a version of Carpet which is stable and sees no disrupting development. The idea is to have two "branches" of Carpet: a stable version for production use, and a development version which might not be as stable. We plan to make the split in about three weeks. The discussion about this is held on the mailing list; your input is welcome.
April 7, 2004: Up to now, all Carpet thorns have been living in a single arrangement for Cactus. This caused problems, because stable thorns, development thorns, and outdated thorns were sitting next to each other, confusing newcomers. We have moved the Carpet arrangement to a new repository and split it into four. Access to the old Carpet arrangement has been disabled.
March 3, 2004: We have recently had trouble with I/O throuth the FlexIO library. We suspect that it might have a bug that causes HDF5 output to fail under certain, random conditions. We have written a new thorn CarpetIOHDF5 which uses the HDF5 library directly, while remaining compatible to the FlexIO file format. Please test this thorn, and report any problems or incompatibilities you find.
In January 2004, Daniel Kobras set up Bugzilla for Carpet. Bugzilla is a bug-tracking system that will, so we hope, help us remember what is missing or broken in Carpet.
In October 2003, Erik Schnetter, Scott H. Hawley, and Ian Hawke published the preprint "Evolutions in 3D numerical relativity using fixed mesh refinement" as gr-qc/0310042. Its main point is to present tests of Carpet with the BSSN code (AEI's spacetime evolution code), and to show that mesh refinement does not introduce instabilities.
In August 2003, these web pages were created.
May 2003 has informally been termed "Carpet month". In a flurry of activity, bugs were fixed and some features added. The BSSN code of the numerical relativity group at the AEI now works together with Carpet.
Last modified: Sat Mar 01 2008