SCM Repository
[matrix] / branches / Matrix-mer2 / inst / doc / UFsparse / COLAMD.txt |
View of /branches/Matrix-mer2/inst/doc/UFsparse/COLAMD.txt
Parent Directory | Revision Log
Revision 1028 -
(download)
(annotate)
Tue Nov 8 23:53:35 2005 UTC (13 years, 11 months ago) by bates
File size: 4077 byte(s)
Tue Nov 8 23:53:35 2005 UTC (13 years, 11 months ago) by bates
File size: 4077 byte(s)
Merging from trunk
The COLAMD ordering method - Version 2.4 ------------------------------------------------------------------------------- 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 colamd2.4/ directory from the colamd2.4.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. Colamd 2.0 is a built-in routine in MATLAB V6.0, available from The Mathworks, Inc. Under most cases, the compiled codes from Versions 2.0 through 2.2 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. To use colamd and symamd within an application written in C, all you need are colamd.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. Copyright (c) 1998-2005, Timothy A. Davis, All Rights Reserved. See http://www.cise.ufl.edu/research/sparse/colamd (the colamd.c file) for the License. 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. Available at ftp://ftp.cise.ufl.edu/cis/tech-reports/tr98/tr98-016.ps via anonymous ftp. 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. Available at http://www.cise.ufl.edu/~davis/Kern/kern.ps Authors: Stefan I. Larimore and Timothy A. Davis, University of Florida, 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 (Version 2.4.) colamd2.4.tar.gz: All files, as a gzipped, Unix tar file. The *.m, and *mex.c files are for use in MATLAB. colamd.c: the primary colamd computational kernel. colamd.h: include file for colamd/symamd library. colamd.m: the MATLAB interface to colamd. colamd_demo.m: MATLAB demo file for colamd and symamd (also compiles the colamdmex and symamdmex mexFunctions). colamdmex.c: colamd mexFunction for use in MATLAB. colamd_example.c: example C main program that calls colamd and symamd. colamd_example.out: output of colamd_example.c. Makefile: Makefile for colamd_example.c symamd.m: the MATLAB interface to symamd. symamdmex.c: symamd mexFunction for use in MATLAB. README: this file ChangeLog: a log of changes since Version 1.0. colamd_test.m: test code colamdtestmex.c: test code luflops.m: test code symamdtestmex.c: test code
root@r-forge.r-project.org | ViewVC Help |
Powered by ViewVC 1.0.0 |