128 lines
5.2 KiB
Plaintext
128 lines
5.2 KiB
Plaintext
The COLAMD ordering method - Version 2.7
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-------------------------------------------------------------------------------
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The COLAMD column approximate minimum degree ordering algorithm computes
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a permutation vector P such that the LU factorization of A (:,P)
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tends to be sparser than that of A. The Cholesky factorization of
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(A (:,P))'*(A (:,P)) will also tend to be sparser than that of A'*A.
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SYMAMD is a symmetric minimum degree ordering method based on COLAMD,
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available as a MATLAB-callable function. It constructs a matrix M such
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that M'*M has the same pattern as A, and then uses COLAMD to compute a column
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ordering of M. Colamd and symamd tend to be faster and generate better
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orderings than their MATLAB counterparts, colmmd and symmmd.
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To compile and test the colamd m-files and mexFunctions, just unpack the
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COLAMD/ directory from the COLAMD.tar.gz file, and run MATLAB from
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within that directory. Next, type colamd_test to compile and test colamd
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and symamd. This will work on any computer with MATLAB (Unix, PC, or Mac).
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Alternatively, type "make" (in Unix) to compile and run a simple example C
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code, without using MATLAB.
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To compile and install the colamd m-files and mexFunctions, just cd to
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COLAMD/MATLAB and type colamd_install in the MATLAB command window.
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A short demo will run. Optionally, type colamd_test to run an extensive tests.
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Type "make" in Unix in the COLAMD directory to compile the C-callable
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library and to run a short demo.
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If you have MATLAB 7.2 or earlier, you must first edit UFconfig/UFconfig.h to
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remove the "-largeArrayDims" option from the MEX command (or just use
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colamd_make.m inside MATLAB).
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Colamd is a built-in routine in MATLAB, available from The
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Mathworks, Inc. Under most cases, the compiled COLAMD from Versions 2.0 to the
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current version do not differ. Colamd Versions 2.2 and 2.3 differ only in their
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mexFunction interaces to MATLAB. v2.4 fixes a bug in the symamd routine in
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v2.3. The bug (in v2.3 and earlier) has no effect on the MATLAB symamd
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mexFunction. v2.5 adds additional checks for integer overflow, so that
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the "int" version can be safely used with 64-bit pointers. Refer to the
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ChangeLog for more details.
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To use colamd and symamd within an application written in C, all you need are
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colamd.c, colamd_global.c, and colamd.h, which are the C-callable
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colamd/symamd codes. See colamd.c for more information on how to call
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colamd from a C program.
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Requires UFconfig, in the ../UFconfig directory relative to this directory.
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Copyright (c) 1998-2007, Timothy A. Davis, All Rights Reserved.
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See http://www.cise.ufl.edu/research/sparse/colamd (the colamd.c
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file) for the License.
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Related papers:
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T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, An approximate column
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minimum degree ordering algorithm, ACM Transactions on Mathematical
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Software, vol. 30, no. 3., pp. 353-376, 2004.
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T. A. Davis, J. R. Gilbert, S. Larimore, E. Ng, Algorithm 836: COLAMD,
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an approximate column minimum degree ordering algorithm, ACM
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Transactions on Mathematical Software, vol. 30, no. 3., pp. 377-380,
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2004.
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"An approximate minimum degree column ordering algorithm",
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S. I. Larimore, MS Thesis, Dept. of Computer and Information
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Science and Engineering, University of Florida, Gainesville, FL,
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1998. CISE Tech Report TR-98-016. Available at
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ftp://ftp.cise.ufl.edu/cis/tech-reports/tr98/tr98-016.ps
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via anonymous ftp.
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Approximate Deficiency for Ordering the Columns of a Matrix,
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J. L. Kern, Senior Thesis, Dept. of Computer and Information
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Science and Engineering, University of Florida, Gainesville, FL,
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1999. Available at http://www.cise.ufl.edu/~davis/Kern/kern.ps
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Authors: Stefan I. Larimore and Timothy A. Davis, University of Florida,
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in collaboration with John Gilbert, Xerox PARC (now at UC Santa Barbara),
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and Esmong Ng, Lawrence Berkeley National Laboratory (much of this work
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he did while at Oak Ridge National Laboratory).
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COLAMD files:
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Demo simple demo
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Doc additional documentation (see colamd.c for more)
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Include include file
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Lib compiled C-callable library
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Makefile primary Unix Makefile
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MATLAB MATLAB functions
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README.txt this file
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Source C source code
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./Demo:
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colamd_example.c simple example
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colamd_example.out output of colamd_example.c
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colamd_l_example.c simple example, long integers
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colamd_l_example.out output of colamd_l_example.c
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Makefile Makefile for C demos
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./Doc:
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ChangeLog change log
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lesser.txt license
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./Include:
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colamd.h include file
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./Lib:
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Makefile Makefile for C-callable library
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./MATLAB:
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colamd2.m MATLAB interface for colamd2
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colamd_demo.m simple demo
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colamd_install.m compile and install colamd2 and symamd2
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colamd_make.m compile colamd2 and symamd2
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colamdmex.ca MATLAB mexFunction for colamd2
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colamd_test.m extensive test
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colamdtestmex.c test function for colamd
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Contents.m contents of the MATLAB directory
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luflops.m test code
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Makefile Makefile for MATLAB functions
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symamd2.m MATLAB interface for symamd2
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symamdmex.c MATLAB mexFunction for symamd2
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symamdtestmex.c test function for symamd
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./Source:
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colamd.c primary source code
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colamd_global.c globally defined function pointers (malloc, free, ...)
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