lemon-project-template-glpk
diff deps/glpk/src/colamd/README @ 9:33de93886c88
Import GLPK 4.47
author | Alpar Juttner <alpar@cs.elte.hu> |
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date | Sun, 06 Nov 2011 20:59:10 +0100 |
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1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/deps/glpk/src/colamd/README Sun Nov 06 20:59:10 2011 +0100 1.3 @@ -0,0 +1,98 @@ 1.4 +NOTE: Files in this subdirectory are NOT part of the GLPK package, but 1.5 + are used with GLPK. 1.6 + 1.7 + The original code was modified according to GLPK requirements by 1.8 + Andrew Makhorin <mao@gnu.org>. 1.9 +************************************************************************ 1.10 +COLAMD/SYMAMD Version 2.7, Copyright (C) 1998-2007, Timothy A. Davis, 1.11 +All Rights Reserved. 1.12 + 1.13 +Description: 1.14 + 1.15 + colamd: an approximate minimum degree column ordering algorithm, 1.16 + for LU factorization of symmetric or unsymmetric matrices, 1.17 + QR factorization, least squares, interior point methods for 1.18 + linear programming problems, and other related problems. 1.19 + 1.20 + symamd: an approximate minimum degree ordering algorithm for 1.21 + Cholesky factorization of symmetric matrices. 1.22 + 1.23 +Purpose: 1.24 + 1.25 + Colamd computes a permutation Q such that the Cholesky factorization 1.26 + of (AQ)'(AQ) has less fill-in and requires fewer floating point 1.27 + operations than A'A. This also provides a good ordering for sparse 1.28 + partial pivoting methods, P(AQ) = LU, where Q is computed prior to 1.29 + numerical factorization, and P is computed during numerical 1.30 + factorization via conventional partial pivoting with row 1.31 + interchanges. Colamd is the column ordering method used in SuperLU, 1.32 + part of the ScaLAPACK library. It is also available as built-in 1.33 + function in MATLAB Version 6, available from MathWorks, Inc. 1.34 + (http://www.mathworks.com). This routine can be used in place of 1.35 + colmmd in MATLAB. 1.36 + 1.37 + Symamd computes a permutation P of a symmetric matrix A such that 1.38 + the Cholesky factorization of PAP' has less fill-in and requires 1.39 + fewer floating point operations than A. Symamd constructs a matrix 1.40 + M such that M'M has the same nonzero pattern of A, and then orders 1.41 + the columns of M using colmmd. The column ordering of M is then 1.42 + returned as the row and column ordering P of A. 1.43 + 1.44 +Authors: 1.45 + 1.46 + The authors of the code itself are Stefan I. Larimore and Timothy A. 1.47 + Davis (davis at cise.ufl.edu), University of Florida. The algorithm 1.48 + was developed in collaboration with John Gilbert, Xerox PARC, and 1.49 + Esmond Ng, Oak Ridge National Laboratory. 1.50 + 1.51 +Acknowledgements: 1.52 + 1.53 + This work was supported by the National Science Foundation, under 1.54 + grants DMS-9504974 and DMS-9803599. 1.55 + 1.56 +License: 1.57 + 1.58 + This library is free software; you can redistribute it and/or 1.59 + modify it under the terms of the GNU Lesser General Public License 1.60 + as published by the Free Software Foundation; either version 2.1 of 1.61 + the License, or (at your option) any later version. 1.62 + 1.63 + This library is distributed in the hope that it will be useful, 1.64 + but WITHOUT ANY WARRANTY; without even the implied warranty of 1.65 + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 1.66 + Lesser General Public License for more details. 1.67 + 1.68 + You should have received a copy of the GNU Lesser General Public 1.69 + License along with this library; if not, write to the Free Software 1.70 + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 1.71 + USA. 1.72 + 1.73 + Permission is hereby granted to use or copy this program under the 1.74 + terms of the GNU LGPL, provided that the Copyright, this License, 1.75 + and the Availability of the original version is retained on all 1.76 + copies. User documentation of any code that uses this code or any 1.77 + modified version of this code must cite the Copyright, this License, 1.78 + the Availability note, and "Used by permission." Permission to 1.79 + modify the code and to distribute modified code is granted, provided 1.80 + the Copyright, this License, and the Availability note are retained, 1.81 + and a notice that the code was modified is included. 1.82 + 1.83 + COLAMD is also available under alternate licenses, contact T. Davis 1.84 + for details. 1.85 + 1.86 +Availability: 1.87 + 1.88 + The colamd/symamd library is available at: 1.89 + 1.90 + http://www.cise.ufl.edu/research/sparse/colamd/ 1.91 + 1.92 +References: 1.93 + 1.94 + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, An approximate 1.95 + column minimum degree ordering algorithm, ACM Transactions on 1.96 + Mathematical Software, vol. 30, no. 3., pp. 353-376, 2004. 1.97 + 1.98 + T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, Algorithm 836: 1.99 + COLAMD, an approximate column minimum degree ordering algorithm, ACM 1.100 + Transactions on Mathematical Software, vol. 30, no. 3., pp. 377-380, 1.101 + 2004.