# The Matrix Project

Welcome to the Matrix project on R-Forge, home of R packages **Matrix** and **MatrixModels**. These provide S4 classes and methods for representing, operating on, and modelling with sparse and dense matrices. Since R version 2.9.0, **Matrix** has belonged to a list of "recommended" packages bundled in standard installations of R (in the default library, alongside **base**). Hence it is typically possible to load a version of **Matrix** "out of the box" (with, as usual, `library(Matrix)`

).

## Installation

The latest release and development versions of **Matrix** can be installed from CRAN and R-Forge, respectively, with:

> install.packages("Matrix")
> install.packages("Matrix", repos = "http://R-Forge.R-project.org")

Older release versions are preserved in the CRAN archive.

Note that *source* installation (as opposed to *binary* installation) requires compilers and other tools; see manual *R Installation and Administration* for platform-specific details.

## Documentation

Indices of available help topics, data sets, and vignettes can be accessed with:

> help(package = "Matrix")
> data(package = "Matrix")
> vignette(package = "Matrix")

Passing `help_type = "html"`

to `help`

renders a hyperlinked version of the index in your browser. Because **Matrix** is "recommended", its index is also hosted here. (The version is that which is bundled in the latest release of R. It will be recent but need not be current.)

Doxygen-generated documentation for the C sources of **Matrix** is hosted here. Do nudge `maintainer("Matrix")`

if it seems to be severely out of date.

Slides for past talks about the Matrix project are hosted here.
## Browsing the source code

The Matrix project is maintained in a Subversion ("SVN") repository. If you have installed Subversion and have `svn`

on your `PATH`

, then you can check out the latest development version of **Matrix** with:

$ svn checkout [-r REV] svn://svn.r-forge.r-project.org/svnroot/matrix/pkg/Matrix [DEST]

where, optionally, `REV`

and `DEST`

specify a revision number and destination path. Without Subversion, one can browse the repository using R-Forge's ViewVC interface or download a tarball produced by `R CMD build`

from CRAN or R-Forge:

> download.packages("Matrix", ".", type = "source")
> download.packages("Matrix", ".", type = "source", repos = "http://R-Forge.R-project.org")

## Bug reports and feature requests

The Matrix project uses trackers provided by R-Forge to manage bug reports and feature requests. An R-Forge user account is required to post. Once logged in, select an appropriate tracker and click "Submit New". Before posting, *do* verify that your issue exists under the latest development version of the relevant package.