Release Announcement

We are pleased to announce the second release (code name "Chandrasekhar") of the Einstein Toolkit, an open, community developed software infrastructure for relativistic astrophysics. This release is mainly a maintenance release incorporating fixes accumulated since the previous release in June 2010, as well as additional test suites.

The Einstein Toolkit is a collection of software components and tools for simulating and analyzing general relativistic astrophysical systems that builds on numerous software efforts in the numerical relativity community including CactusEinstein, the Carpet AMR infrastructure and on the public version of the Whisky hydrodynamics code (now modified and called GRHydro). The Cactus Framework is used as the underlying computational infrastructure providing large-scale parallelization, general computational components, and a model for collaborative, portable code development. The toolkit includes modules to build complete codes for simulating black hole spacetimes as well as systems governed by relativistic hydrodynamics. Current development in the consortium is targeted at providing additional infrastructure for general relativistic magnetohydrodynamics.

The Einstein Toolkit uses a distributed software model and its different modules are developed, distributed, and supported either by the core team of Einstein Toolkit Maintainers, or by individual groups. Where modules are provided by external groups, the Einstein Toolkit Maintainers provide quality control for modules for inclusion in the toolkit and help coordinate support. The Einstein Toolkit Maintainers currently involve postdocs and faculty from five different institutions, and host weekly meetings that are open for anyone to join in.

Guiding principles for the design and implementation of the toolkit include: open, community-driven software development; well thought out and stable interfaces; separation of physics software from computational science infrastructure; provision of complete working production code; training and education for a new generation of researchers.

For more information about using or contributing to the Einstein Toolkit, or to join the Einstein Toolkit Consortium, please visit our web pages at <>.

The Einstein Toolkit is primarily supported by NSF 0903973/0903782/0904015 (CIGR), and also by NSF 0701566/0855892 (XiRel), 0721915 (Alpaca), 0905046/0941653 (PetaCactus) and 0710874 (LONI Grid).

This release comprises the following tools, arrangements, and thorns. Each tool/arrangement/thorn may have its own licencing conditions, but all are available as open source. Green components are new in this release, shown in red are components now not longer part of the Einstein Toolkit:

       Cactus                  Flesh
       CactusBase              Standard Cactus thorns
       CactusExternalNot part of the Einstein Toolkit anymore (use ExternalLibraries/libjpeg instead of jpeg6b)CactusIO
       CactusNumerical         new: InterpToArray
       CactusTest              Various Cactus testsuite thorns
       CactusWave              Wavetoy example thorns

       ExternalLibraries       Interfaces to external libraries (new: OpenSSL, libjpeg, several updates in other thorns)
       Carpet                  Adaptive mesh refinement
       EinsteinAnalysis        Einstein Toolkit
       McLachlan               BSSN implementation
       TAT/TATelliptic         Various thorns

       Kranc                   Automated code generation
       GetComponents           Downloading tools and thorns
       SimFactory              Building code and running simulations

All repositories participating in this release carry a branch ET_2010_11 marking this release. These release branches will be updated if severe errors are found.

This release has been tested on the following systems and architectures:

  • Workstations (AMD, Linux)
  • MacBook Pro notebook (Intel, Mac OS X)
  • Lenovo T61p notebook (Intel, Linux)
  • Blue Drop, NCSA (Power 7, Linux)
  • Abe, NCSA (Intel cluster, Linux)
  • Damiana, AEI (AMD cluster, Linux)
  • Kraken, NICS (Cray XT5, Linux)
  • Philip, LSU (Intel cluster, Linux)
  • Queen Bee, LONI (Intel cluster, Linux)
  • Ranger, TACC (AMD cluster, Linux)

The Simulation Factory contains ready-to-use configuration details for more than 20 additional systems, including most HPC systems at LONI, NERSC, RZG, and TeraGrid.

The Einstein Toolkit thorns contain 132 regression test cases. While all test cases pass on some systems, there are unfortunately also some systems where certain test cases fail. We verified that this is because of accumulation of floating-point round-off error in most cases, and we will discuss this issue in a broader context in the near future.

The Einstein Toolkit web site contains online documentation for its thorns, and pointers for using it to build your own code. There is also a tutorial that explains how to download, build, and run the code for a simple binary black hole evolution. We invite you to join our mailing list <>.

The changes between this and the previous release include (not complete):
  • Several Libraries can now be build in parallel-make mode, increasing compilation speed on some machines a lot.
  • Several Libraries now clean up intermediate files, often using considerably less disk space per configuration.
  • GRHydro includes (disabled, not yet finished) support for MHD. Don't try to use it yet, and don't get confused about that code.
  • Several Libraries have been updated (ExternalLibraries)
  • Simfactory received several updates, and this will likely be the last release with the Perl version.
  • The links in the Reference manual now work (again).
  • A lot of other bugs and testsuites were corrected.

On behalf of the Einstein Toolkit Consortium: the "Chandrasekhar" Release Team

   Gabrielle Allen
   Eloisa Bentivegna
   Tanja Bode
   Peter Diener
   Roland Haas
   Ian Hinder
   Frank Löffler
   Bruno Mundim
   Christian D. Ott
   Erik Schnetter
   Eric Seidel
   Michael Thomas

November 23, 2010