The COLAMD ordering method - Version 2.7
-------------------------------------------------------------------------------

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.

If you have MATLAB 7.2 or earlier, you must first edit UFconfig/UFconfig.h to
remove the "-largeArrayDims" option from the MEX command (or just use
colamd_make.m inside MATLAB).

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 UFconfig, in the ../UFconfig directory relative to this directory.

	Copyright (c) 1998-2007, 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:

    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, ...)