= p_group_cohomology-1.2.p0 = == Description == Modular Cohomology Rings of Finite p-Groups The documentation of the package is provided at http://sage.math.washington.edu/home/SimonKing/Cohomology/ == License == Copyright (C) 2009 Simon A. King and David J. Green Distributed under the terms of the GNU General Public License (GPL), version 2 or later (at your choice). This code is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. The full text of the GPL is available at: http://www.gnu.org/licenses/ The package includes a data base of cohomology rings of the groups of order 64 and provides access to a data base of cohomology rings of the groups of order 128 and 243, located at http://sage.math.washington.edu/home/SimonKing/Cohomology/db/ These data bases are distributed under the Creative Commons Attribution-Share Alike 3.0 License. The full text of this licence is available at http://creativecommons.org/licenses/by-sa/3.0/ == SPKG Maintainers == Simon A. King == Upstream Contact == Simon A. King David J. Green == Acknowledgements == The development of the initial version of this SPKG was funded by the German Science Foundation, DFG project GR 1585/4.1, and was accomplished at the Friedrich Schiller University Jena. Since version 1.0.1, the further work on this SPKG is funded by Marie Curie grant MTKD-CT-2006-042685 and is pursued at the National University of Ireland, Galway. We thank William Stein for giving us access to various computers on which we could build test the SPKG and on which some huge computations could be completed, and acknowledge the support by National Science Foundation Grant No. DMS-0821725. == Dependencies == - The SmallGroups library needs to be installed in GAP. - For p-groups with a prime p>2, we require Singular at least in version 3-1-0. == Special Update/Build Instructions == The package is very likely to not build or at least to not work properly on Motorola processors (because of endianness). Note that most of the code is original. Therefore we included the files from src into the Mercurial repository. The package includes a modified version of the Aachen C-MeatAxe. Since the changes are major, we included the modified sources into the Mercurial repository. A MeatAxe version that comes closest to what we started with is provided in the folder mtxoriginal. == Testing == Our package does not provide a separate test suite for the MeatAxe C-library or David Green's routines for the computation of minimal projective resolutions. But it is of course equipped with extensive doc tests in the Cython code. Note that internet access is required for these tests, as it is attempted to download cohomology rings from a public data base in the web. The scripts ``spkg-check`` and ``spkg-check-quickly`` walk through all public methods of all classes in all modules of our package and perform the respective doc test. ``spkg-check-quickly`` runs over many doc tests at once, which is faster, but makes it sometimes difficult to find out which doc test actually failed. Moreover, since the same Singular sub-process is used for all tests, errors might occur by creating too many temporary variables in the Singular interface (this only occurs on some machines). Therefore, we recommend to use ``spkg-check`` for testing. It tells exactly which doc test failed, and it launches a clean Singular process for any example. Both test suites also check whether there is any method without a doc test. The test suites must be executed in a Sage shell. Note that spkg-check is executed right after installation of the package, if the environment variable SAGE_CHECK is 1 (do "export SAGE_CHECK=1" on the command line before installation). == Changelog == * 1.2.p0 (Dima Pasechnik and Simon King, March 2010): Adding .hgignore (ignoring src/db and mtxoriginal). Adding a robuster test for the existence of the SmallGroups library. * 1.2 (Simon King, October 2009): Modified printing for cocycles, minor bug fixes and code improvements. The data base at sage.math has moved. New: Persistent Group Cohomology (bar codes), based on ideas of Graham Ellis and Simon King. * 1.1 (Simon King August 2009): Yoneda cocomplex, Restricted Massey powers and general Massey products. * 1.0.2 (Simon King, July 2009): Fixing a computation time regression and two minor bugs. Changing Simon King's email address * 1.0.1 (Simon King, July 2009): Licensing GPL 2 or later * 1.0 (Simon King and David Green July 2009): First public version