COLAMD, Copyright 1998-2012, Timothy A. Davis. http://www.suitesparse.com ------------------------------------------------------------------------------- The COLAMD column approximate minimum degree ordering algorithm computes a permutation vector P such that the LU factorization of A (:,P) tends to be sparser than that of A. The Cholesky factorization of (A (:,P))'*(A (:,P)) will also tend to be sparser than that of A'*A. SYMAMD is a symmetric minimum degree ordering method based on COLAMD, available as a MATLAB-callable function. It constructs a matrix M such that M'*M has the same pattern as A, and then uses COLAMD to compute a column ordering of M. Colamd and symamd tend to be faster and generate better orderings than their MATLAB counterparts, colmmd and symmmd. To compile and test the colamd m-files and mexFunctions, just unpack the COLAMD/ directory from the COLAMD.tar.gz file, and run MATLAB from within that directory. Next, type colamd_test to compile and test colamd and symamd. This will work on any computer with MATLAB (Unix, PC, or Mac). Alternatively, type "make" (in Unix) to compile and run a simple example C code, without using MATLAB. To compile and install the colamd m-files and mexFunctions, just cd to COLAMD/MATLAB and type colamd_install in the MATLAB command window. A short demo will run. Optionally, type colamd_test to run an extensive tests. Type "make" in Unix in the COLAMD directory to compile the C-callable library and to run a short demo. Colamd is a built-in routine in MATLAB, available from The Mathworks, Inc. Under most cases, the compiled COLAMD from Versions 2.0 to the current version do not differ. Colamd Versions 2.2 and 2.3 differ only in their mexFunction interaces to MATLAB. v2.4 fixes a bug in the symamd routine in v2.3. The bug (in v2.3 and earlier) has no effect on the MATLAB symamd mexFunction. v2.5 adds additional checks for integer overflow, so that the "int" version can be safely used with 64-bit pointers. Refer to the ChangeLog for more details. To use colamd and symamd within an application written in C, all you need are colamd.c, colamd_global.c, and colamd.h, which are the C-callable colamd/symamd codes. See colamd.c for more information on how to call colamd from a C program. Requires SuiteSparse_config, in the ../SuiteSparse_config directory relative to this directory. See the colamd.c file or http://www.suitesparse.com for the license to COLAMD. Related papers: 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. "An approximate minimum degree column ordering algorithm", S. I. Larimore, MS Thesis, Dept. of Computer and Information Science and Engineering, University of Florida, Gainesville, FL, 1998. CISE Tech Report TR-98-016. Approximate Deficiency for Ordering the Columns of a Matrix, J. L. Kern, Senior Thesis, Dept. of Computer and Information Science and Engineering, University of Florida, Gainesville, FL, 1999. Authors: Stefan I. Larimore and Timothy A. Davis, in collaboration with John Gilbert, Xerox PARC (now at UC Santa Barbara), and Esmong Ng, Lawrence Berkeley National Laboratory (much of this work he did while at Oak Ridge National Laboratory). COLAMD files: Demo simple demo Doc additional documentation (see colamd.c for more) Include include file Lib compiled C-callable library Makefile primary Unix Makefile MATLAB MATLAB functions README.txt this file Source C source code ./Demo: colamd_example.c simple example colamd_example.out output of colamd_example.c colamd_l_example.c simple example, long integers colamd_l_example.out output of colamd_l_example.c Makefile Makefile for C demos ./Doc: ChangeLog change log lesser.txt license ./Include: colamd.h include file ./Lib: Makefile Makefile for C-callable library ./MATLAB: colamd2.m MATLAB interface for colamd2 colamd_demo.m simple demo colamd_install.m compile and install colamd2 and symamd2 colamd_make.m compile colamd2 and symamd2 colamdmex.ca MATLAB mexFunction for colamd2 colamd_test.m extensive test colamdtestmex.c test function for colamd Contents.m contents of the MATLAB directory luflops.m test code Makefile Makefile for MATLAB functions symamd2.m MATLAB interface for symamd2 symamdmex.c MATLAB mexFunction for symamd2 symamdtestmex.c test function for symamd ./Source: colamd.c primary source code colamd_global.c globally defined function pointers (malloc, free, ...)