LDL Version 1.0: a sparse LDL' factorization and solve package.
    Written in C, with both a C and MATLAB mexFunction interface. 

These routines are not terrifically fast (they do not use dense matrix kernels),
but the code is very short and concise.  The purpose is to illustrate the
algorithms in a very concise and readable manner, primarily for educational
purposes.  Although the code is very concise, this package is slightly faster
than the built-in sparse Cholesky factorization in MATLAB 6.5 (chol), when
using the same input permutation.

Quick start (Unix, or Windows with Cygwin):

    To compile, test, and install LDL, you may wish to first obtain a copy of
    AMD from http://www.cise.ufl.edu/research/sparse, and place it in the
    ../AMD directory, relative to this directory.  Next, type "make", which
    will compile the LDL library and three demo main programs (one of which
    requires AMD).  It will also compile the LDL MATLAB mexFunction (if you
    have MATLAB).  Typing "make clean" will remove non-essential files.

Quick start (for MATLAB users);

    To compile, test, and install the LDL mexFunction, start MATLAB in this
    directory and type ldldemo and/or ldltest.  This works on any system
    supported by MATLAB.

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LDL Version 1.0 (Dec. 31, 2003),  Copyright (c) 2003 by Timothy A. Davis.
All Rights Reserved.

LDL License:

    Your use or distribution of LDL or any modified version of
    LDL implies that you agree to this License.

    THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
    EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.

    Permission is hereby granted to use or copy this program, provided
    that the Copyright, this License, and the Availability of the original
    version is retained on all copies.  User documentation of any code that
    uses LDL or any modified version of LDL code must cite the
    Copyright, this License, the Availability note, and "Used by permission."
    Permission to modify the code and to distribute modified code is granted,
    provided the Copyright, this License, and the Availability note are
    retained, and a notice that the code was modified is included.  This
    software was developed with support from the National Science Foundation,
    and is provided to you free of charge.

Availability:

    http://www.cise.ufl.edu/research/sparse/ldl

Acknowledgements:

    This work was supported by the National Science Foundation, under
    grant DMS-0203270.

    Portions of this work were done while on sabbatical at Stanford University
    and Lawrence Berkeley National Laboratory (with funding from the SciDAC
    program).  I would like to thank Gene Golub, Esmond Ng, and Horst Simon
    for making this sabbatical possible.

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Files and directories in this distribution:
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    Documentation, and compiling:

	README		this file
	Makefile	for compiling LDL

    The LDL library itself:

	ldl.c		the C-callable routines
	ldl.h		include file for any code that calls LDL

    A simple C main program that demonstrates how to use LDL:

	ldlsimple.c	a stand-alone C program, uses the basic features of LDL
	ldlsimple.out	output of ldlsimple

    Demo C program, for testing LDL and providing an example of its use

	ldlmain.c	a stand-alone C main program that uses and tests LDL
	Matrix		a directory containing 12 matrices used by ldlmain.c
	ldlmain.out	output of ldlmain
	ldlamd.out	output of ldlamd (ldlmain.c compiled with AMD)

    MATLAB-related, not required for use in a regular C program

	Contents.m	a list of the MATLAB-callable routines
	ldl.m		MATLAB help file for the LDL mexFunction
	ldldemo.m	MATLAB demo of how to use the LDL mexFunction
	ldldemo.out	diary output of ldldemo
	ldltest.m	to test the LDL mexFunction
	ldltest.out	diary output of ldltest
	ldlmex.c	the LDL mexFunction for MATLAB
	ldlrow.m	the numerical algorithm that LDL is based on
	ldlmain2.m	compiles and runs ldlmain.c as a MATLAB mexFunction
	ldlsymbolmex.c	symbolic factorization using LDL (see SYMBFACT, ETREE)
	ldlsymbol.m	help file for the LDLSYMBOL mexFunction

See ldl.c for a description of how to use the code from a C program.  Type
"help ldl" in MATLAB for information on how to use LDL in a MATLAB program.