
The GAP 4 Package `AtlasRep'
============================

Description
-----------

This is Version 1.3 of the package `AtlasRep' written for GAP 4,
whose aim is to provide an interface between GAP
and the Atlas of Group Representations,
a database that comprises representations of many almost simple groups
and information about their maximal subgroups.
This database is available independent of GAP at

    http://brauer.maths.qmul.ac.uk/Atlas.

The AtlasRep package consists of this database and a GAP interface.
The latter allows the user to get an overview of the database,
and to access the data in GAP format.

The package manual, in the `doc' subdirectory, describes the available
functions in detail.
It is based on the GAP package GAPDoc,
available formats are PDF, HTML, and plain text.

The package has been developed on Linux,
a few tests on Windows suggest that is works also there,
it may or may not work on other platforms.

The package requires GAP 4.4 (or a newer version of GAP).


Authors
-------

The data files of the ATLAS of Group Representations have been prepared by
Robert Wilson, Peter Walsh, Jonathan Tripp, Ibrahim Suleiman, Richard Parker,
Simon Norton, Simon Nickerson, Steve Linton, John Bray, and Rachel Abbott
(in reverse alphabetical order).

The GAP interface was written by Thomas Breuer and Simon Nickerson.


Feedback
--------

If you have used the `AtlasRep' package to solve a problem,
please let us know by sending an email to

    Robert A. Wilson  (R.A.Wilson@qmul.ac.uk) or
    Thomas Breuer     (sam@math.rwth-aachen.de)

about it.

Any comments about the package are very welcome.
If you have found important features missing or if there is a bug,
let us know and we will try to address it in the next version of the package.
Messages concerning the data of the package should be sent to Robert Wilson,
messages concerning the GAP interface to Thomas Breuer.


Contents
--------

With this version you should have obtained this README file
and an archive file containing the GAP interface
in the following files and directories:

    datagens        the directory for files with generators
    dataword        the directory for files with straight line programs
    doc             the directory with the package manual
    etc             the directory with a script for updating
                    the table of contents
    gap             the directory with the GAP code
    init.g          the file for initializing the package
    read.g          the file for reading in the package
    tst             the directory with some test files

The archive does *NOT* contain the database part of the package;
the GAP interface accesses the data on demand via the internet.
However, a starter archive (in gzipped tar format)
containing many small representations and programs
can be downloaded from the homepage of the package.


Unpacking
---------

You may have got the GAP interface of the package as
a zoo archive (filename ends with .zoo)
or a compressed tar archive (filename ends with .tar.gz).
In each case, use the appropriate command on your system to unpack
the archive.

On UNIX systems the zoo archive may be unpacked by

    zoo x atlasrep1r3p0.zoo

which will unpack the archive into a directory `atlasrep' in the
current directory.

On UNIX systems the compressed tar archive may be unpacked by

    tar xzf atlasrep1r3p0.tar.gz

or, if tar on your system does not understand the option z, by

    gunzip atlasrep1r3p0.tar.gz
    tar xf atlasrep1r3p0.tar

which will in each case unpack the code into a directory `atlasrep'
in the current directory.

If your system does not have a zoo programme, you can pick up the
C-code for unzoo from the GAP web page and compile it on your system.
For this your system needs to have a C-compiler.
unzoo can be used to unpack the zoo archive, as follows:

    unzoo -x atlasrep1r3p0.zoo

unpacks the archive into a directory `atlasrep' in the current directory.


Installation
------------

Installation of the AtlasRep package means unpacking the archive file
in an appropriate directory.

For the two ways of installing GAP packages in general,
see the sections "Installing GAP Packages" and
"Installing a GAP Package in your home directory"
in the GAP Reference Manual.

Special configuration issues of the AtlasRep package are described
in the following sections of the package manual.

    "Installing the AtlasRep Package",
    "Maintaining the Local Data of the AtlasRep Package", and
    "User Parameters for the AtlasRep Package".

They might be of interest after unpacking the archive.

Once you have successfully installed the AtlasRep package,
start GAP (possibly using the command line option -l) and type

    gap> LoadPackage( "atlasrep" );
    true
    gap>

at the GAP prompt.
Then the functions of the package are available in the current session.

If the GAP package `IO' is not available then the system program `wget'
can be used instead for transferring data files.
For Windows users, `wget' seems to be not available in a standard
operating system.
Information about `wget' for Windows (and executables) can be found at

    href="ttp://www.interlog.com/~tcharron/wgetwin.html


News
----

The internet homepage of the AtlasRep package is

    http://www.math.rwth-aachen.de/~Thomas.Breuer/atlasrep

Besides package archives and introductory package information, it provides

- the current table of contents (the file `gap/atlasprm.g') of the package
  and the list of changes of server files
  (see the section "Maintaining the Local Data of the AtlasRep Package"
  of the package manual) and

- an overview of the data available via the GAP interface to the
  ATLAS of Group Representations,
  similar to the information shown by the function `DisplayAtlasInfo'
  of the package;
  more details can be found on the home page of the ATLAS (see above).

