From bates at stat.wisc.edu  Thu Jan 29 23:35:55 2004
From: bates at stat.wisc.edu (Douglas Bates)
Date: Thu Jan 29 23:36:11 2004
Subject: [Rd] Developmental version of Matrix package for R-1.9.0
Message-ID: <6rekti5qno.fsf@bates4.stat.wisc.edu>

I recently uploaded a developmental version of the Matrix package,
Matrix_0.6-1.tar.gz, to CRAN where it is in the
src/contrib/1.9.0/Other directory.  It requires some of the packages
that will appear in R-1.9.0.

This version marks a major redesign of the Matrix package to use S4
classes and methods and to incorporate sparse matrix manipulations
using routines from TAUCS (http://www.tau.ac.il/~stoledo/taucs/),
Metis (http://www-users.cs.umn.edu/~karypis/metis/) and UMFPACK
(http://www.cise.ufl.edu/research/sparse/umfpack).

Although this package is very much a work in progress and the
documentation is, shall we say, sketchy, there are two vignettes
included with the package.  One of these illustrates the performance
of different ways of performing least squares calculations, using an
example from Koenker and Ng's SparseM package.  The results are, I
think, impressive.

Although not documented in this release, there are the beginnings of
routines to represent large, sparse, pairwise crosstabulations as
sparse matrices.  I am using these in calculations for mixed-effects
models and I understand that others may be interested in them for
other applications.  I would be happy to correspond off-list if you
would like a preview of the capabilities.

Metis is a package for partioning unstructured graphs, partitioning
meshes, and computing fill-reducing orderings of sparse matrices.
Although the entire source code for Metis is included in the Matrix
package I am only using one of the functions for computing
fill-reducing orderings.  Perhaps those who are working on graphical
models may want to look at some of the other capabilities of Metis.
Certainly it provides standard ways of representing and manipulating
unstructured graphs.

I've only compiled and tested the package on Linux_x86 environments.
I will be interested in whether Uwe is successful in building it for
Windows and whether there are problems on 64-bit machines.
-- 
Douglas Bates                            bates@stat.wisc.edu
Statistics Department                    608/262-2598
University of Wisconsin - Madison        http://www.stat.wisc.edu/~bates/


[Rd] Developmental version of Matrix package for R-1.9.0
Douglas Bates