diff -r d59bea55db9b -r c445c931472f src/colamd/README --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/colamd/README Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,98 @@ +NOTE: Files in this subdirectory are NOT part of the GLPK package, but + are used with GLPK. + + The original code was modified according to GLPK requirements by + Andrew Makhorin . +************************************************************************ +COLAMD/SYMAMD Version 2.7, Copyright (C) 1998-2007, Timothy A. Davis, +All Rights Reserved. + +Description: + + colamd: an approximate minimum degree column ordering algorithm, + for LU factorization of symmetric or unsymmetric matrices, + QR factorization, least squares, interior point methods for + linear programming problems, and other related problems. + + symamd: an approximate minimum degree ordering algorithm for + Cholesky factorization of symmetric matrices. + +Purpose: + + Colamd computes a permutation Q such that the Cholesky factorization + of (AQ)'(AQ) has less fill-in and requires fewer floating point + operations than A'A. This also provides a good ordering for sparse + partial pivoting methods, P(AQ) = LU, where Q is computed prior to + numerical factorization, and P is computed during numerical + factorization via conventional partial pivoting with row + interchanges. Colamd is the column ordering method used in SuperLU, + part of the ScaLAPACK library. It is also available as built-in + function in MATLAB Version 6, available from MathWorks, Inc. + (http://www.mathworks.com). This routine can be used in place of + colmmd in MATLAB. + + Symamd computes a permutation P of a symmetric matrix A such that + the Cholesky factorization of PAP' has less fill-in and requires + fewer floating point operations than A. Symamd constructs a matrix + M such that M'M has the same nonzero pattern of A, and then orders + the columns of M using colmmd. The column ordering of M is then + returned as the row and column ordering P of A. + +Authors: + + The authors of the code itself are Stefan I. Larimore and Timothy A. + Davis (davis at cise.ufl.edu), University of Florida. The algorithm + was developed in collaboration with John Gilbert, Xerox PARC, and + Esmond Ng, Oak Ridge National Laboratory. + +Acknowledgements: + + This work was supported by the National Science Foundation, under + grants DMS-9504974 and DMS-9803599. + +License: + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public License + as published by the Free Software Foundation; either version 2.1 of + the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 + USA. + + Permission is hereby granted to use or copy this program under the + terms of the GNU LGPL, provided that the Copyright, this License, + and the Availability of the original version is retained on all + copies. User documentation of any code that uses this code or any + modified version of this code must cite the Copyright, this License, + the Availability note, and "Used by permission." Permission to + modify the code and to distribute modified code is granted, provided + the Copyright, this License, and the Availability note are retained, + and a notice that the code was modified is included. + + COLAMD is also available under alternate licenses, contact T. Davis + for details. + +Availability: + + The colamd/symamd library is available at: + + http://www.cise.ufl.edu/research/sparse/colamd/ + +References: + + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, An approximate + column minimum degree ordering algorithm, ACM Transactions on + Mathematical Software, vol. 30, no. 3., pp. 353-376, 2004. + + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, Algorithm 836: + COLAMD, an approximate column minimum degree ordering algorithm, ACM + Transactions on Mathematical Software, vol. 30, no. 3., pp. 377-380, + 2004.