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<p><a id="X8590688C7EF8F033" name="X8590688C7EF8F033"></a></p>
<div class="ChapSects"><a href="chap1.html#X8590688C7EF8F033">1 <span class="Heading">Introduction to the <strong class="pkg">AtlasRep</strong> Package</span></a>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap1.html#X7B23A1EA7E3711B8">1.1 <span class="Heading">The <strong class="pkg">ATLAS</strong> of Group Representations</span></a>
</span>
</div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap1.html#X869477FF842395E5">1.2 <span class="Heading">The GAP Interface to the <strong class="pkg">ATLAS</strong> of Group Representations</span></a>
</span>
</div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap1.html#X7B545103804AD69A">1.3 <span class="Heading">What's New in <strong class="pkg">AtlasRep</strong>,
Compared to Older Versions?</span></a>
</span>
<div class="ContSSBlock">
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X7EACAC887E257302">1.3-1 <span class="Heading">What's New in Version 1.5.1?
(March 2016)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X86002B747AE0741B">1.3-2 <span class="Heading">What's New in Version 1.5? (July 2011)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X878EBA108716DDF0">1.3-3 <span class="Heading">What's New in Version 1.4? (June 2008)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X87A53CE182C9E086">1.3-4 <span class="Heading">What's New in Version 1.3.1? (October 2007)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X79CCC5517897924C">1.3-5 <span class="Heading">What's New in Version 1.3? (June 2007)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X7BDCA94D83DCFFB8">1.3-6 <span class="Heading">What's New in Version 1.2? (November 2003)</span></a>
</span>
<span class="ContSS"><br /><span class="nocss"> </span><a href="chap1.html#X831628B47F669B29">1.3-7 <span class="Heading">What's New in Version 1.1? (October 2002)</span></a>
</span>
</div></div>
<div class="ContSect"><span class="tocline"><span class="nocss"> </span><a href="chap1.html#X82A988D47DFAFCFA">1.4 <span class="Heading">Acknowledgements</span></a>
</span>
</div>
</div>
<h3>1 <span class="Heading">Introduction to the <strong class="pkg">AtlasRep</strong> Package</span></h3>
<p>The aim of the <strong class="pkg">GAP</strong> 4 package <strong class="pkg">AtlasRep</strong> is to provide a link between <strong class="pkg">GAP</strong> and the "<strong class="pkg">ATLAS</strong> of Group Representations" <a href="chapBib.html#biBAGRv3">[ATLAS]</a>, a database that comprises generating permutations and matrices for many almost simple groups, and information about their maximal subgroups. This database is available independent of <strong class="pkg">GAP</strong> at</p>
<p><span class="URL"><a href="http://brauer.maths.qmul.ac.uk/Atlas">http://brauer.maths.qmul.ac.uk/Atlas</a></span></p>
<p>The <strong class="pkg">AtlasRep</strong> package consists of this database (see Section <a href="chap1.html#X7B23A1EA7E3711B8"><span class="RefLink">1.1</span></a>) and a <strong class="pkg">GAP</strong> interface (see Section <a href="chap1.html#X869477FF842395E5"><span class="RefLink">1.2</span></a>); the latter is extended by further information available via the internet (see Section <a href="chap4.html#X876E8147820EABAF"><span class="RefLink">4.4</span></a>).</p>
<p>This package manual has the following parts.</p>
<dl>
<dt><strong class="Mark">A tutorial</strong></dt>
<dd><p>gives an overview how the functions of the package can be used, see Chapter <a href="chap2.html#X8502B3798180E78D"><span class="RefLink">2</span></a>.</p>
</dd>
<dt><strong class="Mark">User interface functions</strong></dt>
<dd><p>are described in Chapter <a href="chap3.html#X79CC2FC07C77EB2C"><span class="RefLink">3</span></a>.</p>
</dd>
<dt><strong class="Mark">Customizations of the package</strong></dt>
<dd><p>are described in Chapter <a href="chap4.html#X7DBC1D157F0EE283"><span class="RefLink">4</span></a>.</p>
</dd>
<dt><strong class="Mark">Information how to extend the database</strong></dt>
<dd><p>can be found in Chapter <a href="chap5.html#X7B33345C7B304697"><span class="RefLink">5</span></a>.</p>
</dd>
<dt><strong class="Mark">More technical information</strong></dt>
<dd><p>can be found in the chapters <a href="chap6.html#X7EFB2E2A7857AC06"><span class="RefLink">6</span></a> (concerning <strong class="pkg">GAP</strong> objects that are introduced by the package) and <a href="chap7.html#X812769A8852CF93E"><span class="RefLink">7</span></a> (concerning global variables and sanity checks).</p>
</dd>
</dl>
<p><a id="X7B23A1EA7E3711B8" name="X7B23A1EA7E3711B8"></a></p>
<h4>1.1 <span class="Heading">The <strong class="pkg">ATLAS</strong> of Group Representations</span></h4>
<p>The <strong class="pkg">ATLAS</strong> of Group Representations consists of matrices over various rings, permutations, and shell scripts encoding so-called black box programs (see <a href="chapBib.html#biBNic06">[Nic06]</a> and Section <a href="chap6.html#X7BE856BC785A9E8F"><span class="RefLink">6.2</span></a>). Many of these scripts are straight line programs (see <a href="chapBib.html#biBBSW01">[BSWW01]</a>, <a href="chapBib.html#biBSWW00">[SWW00]</a>, and <a href="../../../doc/ref/chap37.html#X7DC99E4284093FBB"><span class="RefLink">Reference: Straight Line Programs</span></a>) and straight line decisions (see Section <a href="chap6.html#X8121E9567A7137C9"><span class="RefLink">6.1</span></a>). These programs can be used to compute certain elements in a group <span class="SimpleMath">G</span> from its standard generators (see <a href="chapBib.html#biBWil96">[Wil96]</a> and Section <a href="chap3.html#X7F53EDAB7992C192"><span class="RefLink">3.3</span></a>) for example generators of maximal subgroups of <span class="SimpleMath">G</span> or representatives of conjugacy classes of <span class="SimpleMath">G</span>.</p>
<p>The <strong class="pkg">ATLAS</strong> of Group Representations has 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).</p>
<p>The information was computed and composed using computer algebra systems such as <strong class="pkg">MeatAxe</strong> (see <a href="chapBib.html#biBCMeatAxe">[Rin]</a>), Magma (see <a href="chapBib.html#biBCP96">[CP96]</a>), and <strong class="pkg">GAP</strong> (in reverse alphabetical order). Part of the constructions have been documented in the literature on almost simple groups, or the results have been used in such publications, see for example the references in <a href="chapBib.html#biBCCN85">[CCNPW85]</a> and <a href="chapBib.html#biBBN95">[BN95]</a>.</p>
<p>If you use the <strong class="pkg">ATLAS</strong> of Group Representations to solve a problem then please send a short email to <span class="URL"><a href="mailto:R.A.Wilson@qmul.ac.uk">R.A.Wilson@qmul.ac.uk</a></span> about it. The <strong class="pkg">ATLAS</strong> of Group Representations database should be referenced with the entry <a href="chapBib.html#biBAGRv3">[ATLAS]</a> in the bibliography of this manual.</p>
<p>If your work made use of functions of the <strong class="pkg">GAP</strong> interface (see Section <a href="chap1.html#X869477FF842395E5"><span class="RefLink">1.2</span></a>) then you should also reference this interface, as follows.</p>
<div class="example"><pre>
@misc{ AtlasRep1.5.1,
author = {Wilson, R. A. and Parker, R. A. and Nickerson, S. and
Bray, J. N. and Breuer, T.},
title = {{AtlasRep}, A \textsf{GAP} Interface to the Atlas of
Group Representations,
{V}ersion 1.5.1},
month = {March},
year = {2016},
note = {\textsf{GAP} package},
howpublished = {http://www.math.rwth-aachen.de/\~{}Thomas.Breuer/atlasrep}
}
</pre></div>
<p>For referencing the <strong class="pkg">GAP</strong> system in general, use the entry <a href="chapBib.html#biBGAP">[GAP]</a> in the bibliography of this manual, see also</p>
<p><span class="URL"><a href="http://www.gap-system.org">http://www.gap-system.org</a></span>.</p>
<p><a id="X869477FF842395E5" name="X869477FF842395E5"></a></p>
<h4>1.2 <span class="Heading">The GAP Interface to the <strong class="pkg">ATLAS</strong> of Group Representations</span></h4>
<p>The <strong class="pkg">GAP</strong> interface to the <strong class="pkg">ATLAS</strong> of Group Representations consists of essentially two parts.</p>
<ul>
<li><p>First, there is the <em>user interface</em> which allows the user to get an overview of the contents of the database, and to access the data in <strong class="pkg">GAP</strong> format; this is described in Chapter <a href="chap3.html#X79CC2FC07C77EB2C"><span class="RefLink">3</span></a>. Advanced users may add their own data to the database, this is described in Chapter <a href="chap5.html#X7B33345C7B304697"><span class="RefLink">5</span></a>.</p>
</li>
<li><p>Second, there is <em>administrational information</em>, which covers also the declaration of <strong class="pkg">GAP</strong> objects such as straight line decisions and black box programs. This is important mainly for users interested in the actual implementation (e. g., for modifying the package) or in using it together with the <code class="code">C</code>-<strong class="pkg">MeatAxe</strong> standalone (see <a href="chapBib.html#biBCMeatAxe">[Rin]</a>); this is described in Chapter <a href="chap7.html#X812769A8852CF93E"><span class="RefLink">7</span></a>.</p>
</li>
</ul>
<p>Information concerning the <code class="code">C</code>-<strong class="pkg">MeatAxe</strong>, including the manual <a href="chapBib.html#biBCMeatAxe">[Rin]</a>, can be found at</p>
<p><span class="URL"><a href="http://www.math.rwth-aachen.de/LDFM/homes/MTX">http://www.math.rwth-aachen.de/LDFM/homes/MTX</a></span></p>
<p>The interface and this manual have been provided by Thomas Breuer, except for the interpreter for black box programs (see Section <a href="chap6.html#X7BE856BC785A9E8F"><span class="RefLink">6.2</span></a>), which is due to Simon Nickerson. Comments, bug reports, and hints for improving the interface can be sent to <span class="URL"><a href="mailto:sam@math.rwth-aachen.de">sam@math.rwth-aachen.de</a></span>.</p>
<p><a id="X7B545103804AD69A" name="X7B545103804AD69A"></a></p>
<h4>1.3 <span class="Heading">What's New in <strong class="pkg">AtlasRep</strong>,
Compared to Older Versions?</span></h4>
<p><a id="sect:news"/></p>
<p><a id="X7EACAC887E257302" name="X7EACAC887E257302"></a></p>
<h5>1.3-1 <span class="Heading">What's New in Version 1.5.1?
(March 2016)</span></h5>
<ul>
<li><p>The paths of the directories where downloaded data files get stored are now customizable, see Section <a href="chap4.html#X7F6F45758688CBC7"><span class="RefLink">4.3-9</span></a>. Up to now, the data were stored in subdirectories of the package directory, which might cause problems with write permissions, depending on the installation of the package. (Note that choosing other data directories can be useful also in order to keep existing local data files when a new version of <strong class="pkg">GAP</strong> or of the <strong class="pkg">AtlasRep</strong> package gets installed.) Thanks to Bill Allombert for pointing out this problem.</p>
</li>
<li><p>The information about data files from the <strong class="pkg">ATLAS</strong> of Group Representations has been extended by <code class="func">CrcFile</code> (<a href="../../../doc/ref/chap9.html#X8241CEAD80415BB9"><span class="RefLink">Reference: CrcFile</span></a>) values. These values are checked whenever data from such a file are read, and an error is signalled if the checksum does not fit to the expected one. Note that several users may access the same data files, and a user should not suffer from perhaps corrupted files that have been downloaded by other users. Thanks to Frank Lübeck for the idea to introduce this consistency test.</p>
</li>
<li><p>Whenever <code class="func">StringFile</code> (<a href="../../../pkg/GAPDoc/doc/chap6.html#X7E14D32181FBC3C3"><span class="RefLink">GAPDoc: StringFile</span></a>) is called by functions of the package, this happens in the wrapper function <code class="code">AGR.StringFile</code>, in order to replace occasional line breaks of the form <code class="code">"\r\n"</code> by <code class="code">"\n"</code>. Apparently it may happen that the <code class="code">"\r"</code> is silently smuggled in when data files get copied to the local computer. Thanks to Marek Mitros for help with detecting and fixing this problem.</p>
</li>
<li><p>The function <code class="func">FFMatOrPermCMtxBinary</code> (<a href="chap7.html#X872FA00C7F791FBB"><span class="RefLink">7.3-5</span></a>) can now read also permutations stored in binary files that have been created with version 2.4 of the C-<strong class="pkg">MeatAxe</strong>; note that this format is different from the one that is written by version 2.3. Conversely, <code class="func">CMtxBinaryFFMatOrPerm</code> (<a href="chap7.html#X8477AA668733255C"><span class="RefLink">7.3-4</span></a>) has been generalized such that both formats can be written. The reference to the C-<strong class="pkg">MeatAxe</strong> documentation now points to that of version 2.4. Thanks to Jürgen Müller for pointing out this problem.</p>
</li>
<li><p>The function <code class="func">MeatAxeString</code> (<a href="chap7.html#X7DDD09BE87063052"><span class="RefLink">7.3-2</span></a>) can now encode permutation matrices in different ways. The mode (the first header entry) can be either 2 (then the positions of the nonzero entries are listed) or 1 or 6 (then all entries of the matrix are listed). In previous versions, the function produced a matrix of mode 2 whenever this was possible, but this behaviour is not useful if the result is not processed by the C-<strong class="pkg">MeatAxe</strong>. Thanks to Klaus Lux for pointing out this problem.</p>
</li>
<li><p>Depending on the terminal capabilities and the value of <code class="code">AtlasOfGroupRepresentationsInfo.displayFunction</code>, some non-ASCII characters may appear in the output shown by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>).</p>
</li>
</ul>
<p><a id="X86002B747AE0741B" name="X86002B747AE0741B"></a></p>
<h5>1.3-2 <span class="Heading">What's New in Version 1.5? (July 2011)</span></h5>
<ul>
<li><p>The function <code class="func">AtlasSubgroup</code> (<a href="chap3.html#X7A3E460C82B3D9A3"><span class="RefLink">3.5-8</span></a>) now admits also the return value of <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) or the return value of <code class="func">AtlasGroup</code> (<a href="chap3.html#X80AABEE783363B70"><span class="RefLink">3.5-7</span></a>) as its first argument. The latter is implemented via the new attribute <code class="func">AtlasRepInfoRecord</code> (<a href="chap3.html#X87AFEC90873BCDD1"><span class="RefLink">3.5-9</span></a>), which is set in the groups constructed by <code class="func">AtlasGroup</code> (<a href="chap3.html#X80AABEE783363B70"><span class="RefLink">3.5-7</span></a>).</p>
</li>
<li><p>Information about transitivity, rank, primitivity, and point stabilizers of many permutation representations is now available. If applicable then this information appears in the records returned by <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), it is part of the overview shown by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), and it is shown also in the data overview in the web, see Section <a href="chap4.html#X876E8147820EABAF"><span class="RefLink">4.4</span></a>.</p>
<p>Two new manual sections about point stabilizers have been added, see the sections <a href="chap2.html#X79E261637D309687"><span class="RefLink">2.4-6</span></a> and <a href="chap2.html#X7C77816A878B37C4"><span class="RefLink">2.4-7</span></a>.</p>
</li>
<li><p>Information about the characters afforded by many matrix and permutation representations is now available. If applicable then this information appears in the records returned by <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), for matrix representations it is part of the overview shown by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), and it is shown also in the data overview in the web, see Section <a href="chap4.html#X876E8147820EABAF"><span class="RefLink">4.4</span></a>.</p>
</li>
<li><p>The functions <code class="func">Character</code> (<a href="../../../doc/ref/chap72.html#X849DD34C7968206C"><span class="RefLink">Reference: Character (for a character table and a list)</span></a>), <code class="func">Identifier</code> (<a href="../../../doc/ref/chap71.html#X79C40EE97890202F"><span class="RefLink">Reference: Identifier (for character tables)</span></a>), <code class="func">IsPrimitive</code> (<a href="../../../doc/ref/chap41.html#X84C19AD68247B760"><span class="RefLink">Reference: IsPrimitive</span></a>), <code class="func">IsTransitive</code> (<a href="../../../doc/ref/chap41.html#X79B15750851828CB"><span class="RefLink">Reference: IsTransitive</span></a>), <code class="func">Transitivity</code> (<a href="../../../doc/ref/chap41.html#X8295D733796B7A37"><span class="RefLink">Reference: Transitivity</span></a>), and <code class="func">RankAction</code> (<a href="../../../doc/ref/chap41.html#X8166A6A17C8D6E73"><span class="RefLink">Reference: RankAction</span></a>) are now supported as input conditions in <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), etc..</p>
</li>
<li><p>It is now possible to restrict the data shown by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>) to private or non-private data. Also the data returned by <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) can be restricted to private or non-private data.</p>
</li>
<li><p>A tutorial for beginners was added to the manual, see Chapter <a href="chap2.html#X8502B3798180E78D"><span class="RefLink">2</span></a>, and the manual was restructured.</p>
</li>
<li><p>In the overview shown by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>) and in the data overview in the web (see Section <a href="chap4.html#X876E8147820EABAF"><span class="RefLink">4.4</span></a>), the ordering of groups was improved such that, e.g., <code class="code">"A9"</code> precedes <code class="code">"A10"</code>.</p>
</li>
<li><p>The function <code class="func">AtlasClassNames</code> (<a href="chap3.html#X78166D1D7D18EFBF"><span class="RefLink">3.4-2</span></a>) now admits also a Brauer table as its argument, and works also for character tables of bicyclic extensions of simple groups.</p>
</li>
<li><p>The group names that are entered in <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), etc., are now case insensitive, and if the package <strong class="pkg">CTblLib</strong> is available then the admissible group names for the <strong class="pkg">GAP</strong> character table of the group in question can be used in these functions.</p>
</li>
<li><p>In order to reduce the number of global variables, several functions have been turned into components of the new global variable <code class="func">AGR</code> (<a href="chap7.html#X84A157BF7D0CB270"><span class="RefLink">7.1-5</span></a>). A few of these functions had been documented in the previous version, the old values are still available if the package file <code class="file">gap/obsolete.g</code> has been read. This file is read automatically when the package gets loaded if <code class="code">GAPInfo.UserPreferences.ReadObsolete</code> is <code class="keyw">true</code>, see <a href="../../../doc/ref/chap3.html#X87DF11C885E73583"><span class="RefLink">Reference: The gap.ini file</span></a>.</p>
</li>
<li><p>A few nicer characters are used by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>) if <code class="code">GAPInfo.TermEncoding</code> has the value <code class="code">"UTF-8"</code> and if <code class="code">AtlasOfGroupRepresentationsInfo.displayFunction</code> is different from <code class="func">Print</code> (<a href="../../../doc/ref/chap6.html#X7AFA64D97A1F39A3"><span class="RefLink">Reference: Print</span></a>), see Section <a href="chap4.html#X7DAC8E1E7A419360"><span class="RefLink">4.3-5</span></a>.</p>
</li>
<li><p>A bug in the function <code class="func">ReloadAtlasTableOfContents</code> (<a href="chap4.html#X7AC3EA317EDBDA0E"><span class="RefLink">4.2-1</span></a>) was fixed. Thanks to Jack Schmidt for reporting this bug.</p>
</li>
</ul>
<p><a id="X878EBA108716DDF0" name="X878EBA108716DDF0"></a></p>
<h5>1.3-3 <span class="Heading">What's New in Version 1.4? (June 2008)</span></h5>
<ul>
<li><p>In addition to the group orders that were added in version 1.3 (see Section <a href="chap1.html#X79CCC5517897924C"><span class="RefLink">1.3-5</span></a>), also many orders of maximal subgroups are now available. These values occur in the records returned by <code class="func">AtlasProgram</code> (<a href="chap3.html#X801F2E657C8A79ED"><span class="RefLink">3.5-3</span></a>) (for the case of <code class="code">"maxes"</code> type programs) and of the three argument version of <code class="func">AtlasGenerators</code> (<a href="chap3.html#X7D1CCCF8852DFF39"><span class="RefLink">3.5-2</span></a>); now a <code class="code">size</code> component may be bound. In these cases, the groups returned by <code class="func">AtlasSubgroup</code> (<a href="chap3.html#X7A3E460C82B3D9A3"><span class="RefLink">3.5-8</span></a>) have the <code class="func">Size</code> (<a href="../../../doc/ref/chap30.html#X858ADA3B7A684421"><span class="RefLink">Reference: Size</span></a>) attribute set.</p>
</li>
<li><p>The information about the number of maximal subgroups, if available, is now used in <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>).</p>
</li>
<li><p>In many cases, straight line programs for computing generators of maximal subgroups of a group <span class="SimpleMath">G</span>, say, can in fact be used to compute also generators of maximal subgroups of downward extensions of <span class="SimpleMath">G</span>; if not then it may suffice to extend the given straight line programs by additional generators.</p>
<p>Currently this yields more than <span class="SimpleMath">200</span> new possibilities to compute maximal subgroups, this means a growth by about <span class="SimpleMath">25</span> percent. For example, all maximal subgroups of <span class="SimpleMath">12.M_22</span> and <span class="SimpleMath">2.Fi_22</span> can now be accessed via <code class="func">AtlasGenerators</code> (<a href="chap3.html#X7D1CCCF8852DFF39"><span class="RefLink">3.5-2</span></a>).</p>
<p>(Of course this extension means only that one can access the straight line programs in question automatically via the <strong class="pkg">GAP</strong> interface. In principle one could have used them already before, by explicitly applying a straight line program for a factor group to generators of a group, and perhaps adding some element in the kernel of the natural epimorphism.)</p>
<p>For this feature, information about the compatibility of standard generators of groups and their factor groups was added.</p>
</li>
<li><p>The bibliographies contained in the <strong class="pkg">ATLAS</strong> of Finite Groups <a href="chapBib.html#biBCCN85">[CCNPW85]</a> and in the <strong class="pkg">ATLAS</strong> of Brauer Characters <a href="chapBib.html#biBJLPW95">[JLPW95]</a> are now available, see <code class="func">BrowseBibliographySporadicSimple</code> (<a href="chap3.html#X84ED4FC182C28198"><span class="RefLink">3.6-2</span></a>).</p>
</li>
<li><p>If the <strong class="pkg">GAP</strong> package <strong class="pkg">Browse</strong> (see <a href="chapBib.html#biBBrowse">[BL14]</a>) is loaded then the new functions <code class="func">BrowseMinimalDegrees</code> (<a href="chap3.html#X7F31A7CB841FE63F"><span class="RefLink">3.6-1</span></a>) and <code class="func">BrowseBibliographySporadicSimple</code> (<a href="chap3.html#X84ED4FC182C28198"><span class="RefLink">3.6-2</span></a>) are available; these functions can be called also by choosing the corresponding menu entries of the <strong class="pkg">Browse</strong> application <code class="func">BrowseGapData</code> (<span class="RefLink">???</span>).</p>
</li>
<li><p>The function <code class="func">AtlasGroup</code> (<a href="chap3.html#X80AABEE783363B70"><span class="RefLink">3.5-7</span></a>) now admits also the return value of <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) as its argument.</p>
</li>
</ul>
<p><a id="X87A53CE182C9E086" name="X87A53CE182C9E086"></a></p>
<h5>1.3-4 <span class="Heading">What's New in Version 1.3.1? (October 2007)</span></h5>
<p>This version was mainly released in order to fix a few problems. Now one does not get warnings about unbound variables when the package is loaded and the <strong class="pkg">GAP</strong> package <strong class="pkg">IO</strong> <a href="chapBib.html#biBIO">[Neu14]</a> is not available, and pathological situations in <code class="func">FFMatOrPermCMtxBinary</code> (<a href="chap7.html#X872FA00C7F791FBB"><span class="RefLink">7.3-5</span></a>) (concerning extremely short corrupted data files and different byte orderings in binary files) are handled more carefully.</p>
<p>Besides this, the two functions <code class="func">AtlasGroup</code> (<a href="chap3.html#X80AABEE783363B70"><span class="RefLink">3.5-7</span></a>) and <code class="func">AtlasSubgroup</code> (<a href="chap3.html#X7A3E460C82B3D9A3"><span class="RefLink">3.5-8</span></a>) were introduced, and the extended function <code class="func">QuaternionAlgebra</code> (<a href="../../../doc/ref/chap62.html#X83DF4BCC7CE494FC"><span class="RefLink">Reference: QuaternionAlgebra</span></a>) of <strong class="pkg">GAP</strong> 4.4.10 can now be used for describing base rings in <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>). (This is the reason why this version of the package requires at least version 4.4.10 of <strong class="pkg">GAP</strong>.)</p>
<p><a id="X79CCC5517897924C" name="X79CCC5517897924C"></a></p>
<h5>1.3-5 <span class="Heading">What's New in Version 1.3? (June 2007)</span></h5>
<ul>
<li><p>The database was extended, see Section <a href="chap4.html#X7E0AC1127B4363E7"><span class="RefLink">4.3-4</span></a> for the number and size of files.</p>
</li>
<li><p>New data types and corresponding <strong class="pkg">GAP</strong> objects have been introduced, for representing semi-presentations, presentations, and programs for finding standard generators. For details, see <code class="func">AtlasProgram</code> (<a href="chap3.html#X801F2E657C8A79ED"><span class="RefLink">3.5-3</span></a>), Chapter <a href="chap6.html#X7EFB2E2A7857AC06"><span class="RefLink">6</span></a>, and Section <a href="chap7.html#X7C2562A978319179"><span class="RefLink">7.6</span></a>.</p>
</li>
<li><p>The records returned by the functions <code class="func">AtlasGenerators</code> (<a href="chap3.html#X7D1CCCF8852DFF39"><span class="RefLink">3.5-2</span></a>), <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>) now contain the name and (if known) the order of the group in question, and also components describing the degree in the case of permutation representations or the dimension and the base ring of the natural module in the case of matrix representations.</p>
</li>
<li><p>For many of the groups, information about the minimal degree of faithful permutation representations and the minimal dimensions of faithful matrix representations in various characteristics is available for <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>), see also Section <a href="chap6.html#X87E1F08D80C9E069"><span class="RefLink">6.3</span></a>. For these functions, also properties such as <code class="func">IsPrimeInt</code> (<a href="../../../doc/ref/chap14.html#X78FDA4437EDCA70C"><span class="RefLink">Reference: IsPrimeInt</span></a>) can be used to describe the intended restriction of the output.</p>
</li>
<li><p>One can now use <code class="func">Pager</code> (<a href="../../../doc/ref/chap2.html#X7ED03E41792C3840"><span class="RefLink">Reference: Pager</span></a>) functionality in <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), see Section <a href="chap4.html#X7DAC8E1E7A419360"><span class="RefLink">4.3-5</span></a>.</p>
<p>An interactive alternative to <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>) is provided by the function <code class="func">BrowseAtlasInfo</code> (<span class="RefLink">???</span>) from the new (recommended) <strong class="pkg">GAP</strong> package <strong class="pkg">Browse</strong> <a href="chapBib.html#biBBrowse">[BL14]</a>.</p>
</li>
<li><p>The functions <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>) now admit also a list of group names as the first argument.</p>
</li>
<li><p>The functions for actually accessing the data are more flexible now, see Section <a href="chap4.html#X7FA485E479F6C3A0"><span class="RefLink">4.3-6</span></a>.</p>
</li>
<li><p>For transferring remote data, the <strong class="pkg">GAP</strong> package <strong class="pkg">IO</strong> <a href="chapBib.html#biBIO">[Neu14]</a> can now be used (and is recommended) as an alternative to <code class="file">wget</code>, see Section <a href="chap4.html#X7D58635A79A666DB"><span class="RefLink">4.3-3</span></a>.</p>
</li>
<li><p>The address of the data server has changed. Since the access to the server is no longer possible via <code class="file">ftp</code>, the mechanim used up to version 1.2, which was based on <code class="file">ftp</code>, had to be rewritten.</p>
<p>The main consequence of this change is that information about updates of the table of contents is now provided at the package's homepage. This means that on the one hand, now package users cannot <em>compute</em> the table of contents directly from the server data, but on the other hand the update information can be <em>downloaded</em> without the necessity to install <code class="file">perl</code>.</p>
<p>Another consequence is that the system program <code class="file">ls</code> is no longer needed, see Section <a href="chap1.html#X831628B47F669B29"><span class="RefLink">1.3-7</span></a>.</p>
</li>
<li><p>The package manual has been restructured, extended and improved. It is now based on the package <strong class="pkg">GAPDoc</strong> <a href="chapBib.html#biBGAPDoc">[LN12]</a>.</p>
</li>
</ul>
<p><a id="X7BDCA94D83DCFFB8" name="X7BDCA94D83DCFFB8"></a></p>
<h5>1.3-6 <span class="Heading">What's New in Version 1.2? (November 2003)</span></h5>
<p>Not much.</p>
<p>The release of Version 1.2 became necessary first of all in order to provide a package version that is compatible with <strong class="pkg">GAP</strong> 4.4, since some cross-references into the <strong class="pkg">GAP</strong> Reference Manual were broken due to changes of section names. Additionally, several web addresses concerning the package itself were changed and thus had to be adjusted.</p>
<p>This opportunity was used</p>
<ul>
<li><p>to upgrade the administrational part for loading the package to the mechanism that is recommended for <strong class="pkg">GAP</strong> 4.4,</p>
</li>
<li><p>to extend the test suite, which now covers more consistency checks using the <strong class="pkg">GAP</strong> Character Table Library <a href="chapBib.html#biBCTblLib">[Bre13]</a>,</p>
</li>
<li><p>to make the function <code class="func">ScanMeatAxeFile</code> (<a href="chap7.html#X83D5103780E1238F"><span class="RefLink">7.3-1</span></a>) more robust, due to the fact that the <strong class="pkg">GAP</strong> function <code class="func">PermList</code> (<a href="../../../doc/ref/chap42.html#X78D611D17EA6E3BC"><span class="RefLink">Reference: PermList</span></a>) now returns <code class="keyw">fail</code> instead of raising an error,</p>
</li>
<li><p>to change the way how representations with prescribed properties are accessed (the new function <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>) is now preferred to the former <code class="code">OneAtlasGeneratingSet</code>, and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>) has been added in order to provide programmatic access in parallel to the human readable descriptions printed by <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>)),</p>
</li>
<li><p>and last but not least to include the current table of contents of the underlying database.</p>
</li>
</ul>
<p>For <strong class="pkg">AtlasRep</strong> users, the new feature of <strong class="pkg">GAP</strong> 4.4 is particularly interesting that due to better kernel support, reading large matrices over finite fields is now faster than it was in <strong class="pkg">GAP</strong> 4.3.</p>
<p><a id="X831628B47F669B29" name="X831628B47F669B29"></a></p>
<h5>1.3-7 <span class="Heading">What's New in Version 1.1? (October 2002)</span></h5>
<p>The biggest change w.r.t. Version 1.1 is the addition of private extensions (see Chapter <a href="chap5.html#X7B33345C7B304697"><span class="RefLink">5</span></a>). It includes a new "free format" for straight line programs (see Section <a href="chap5.html#X7E186BFA7E59BD47"><span class="RefLink">5.2</span></a>). Unfortunately, this feature requires the system program <code class="file">ls</code>, so it may be not available for example under MS Windows operating systems. [But see Section <a href="chap1.html#X79CCC5517897924C"><span class="RefLink">1.3-5</span></a>.]</p>
<p>In order to admit the addition of other types of data, the implementation of several functions has been changed. Data types are described in Section <a href="chap7.html#X7C164C4D7ECE62D0"><span class="RefLink">7.5</span></a>. An example of a new data type are quaternionic representations (see Section <a href="chap7.html#X7C2562A978319179"><span class="RefLink">7.6</span></a>). The user interface itself (see Chapter <a href="chap3.html#X79CC2FC07C77EB2C"><span class="RefLink">3</span></a>) remained the same.</p>
<p>As an alternative to <code class="code">perl</code>, one can use <code class="code">wget</code> now for transferring data files (see <a href="chap4.html#X81358A377CC2C463"><span class="RefLink">4.3</span></a>).</p>
<p>Data files can be read much more efficiently in <strong class="pkg">GAP</strong> 4.3 than in <strong class="pkg">GAP</strong> 4.2. In Version 1.1 of the <strong class="pkg">AtlasRep</strong> package, this feature is used for reading matrices and permutations in <strong class="pkg">MeatAxe</strong> text format with <code class="func">ScanMeatAxeFile</code> (<a href="chap7.html#X83D5103780E1238F"><span class="RefLink">7.3-1</span></a>). As a consequence, (at least) <strong class="pkg">GAP</strong> 4.3 is required for <strong class="pkg">AtlasRep</strong> Version 1.1.</p>
<p>The new <code class="code">compress</code> component of the global variable <code class="func">AtlasOfGroupRepresentationsInfo</code> (<a href="chap7.html#X7BEC94A6781E126E"><span class="RefLink">7.1-6</span></a>) allows one to store data files automatically in <code class="file">gzip</code>ped form.</p>
<p>For matrix representations in characteristic zero, invariant forms and generators for the centralizer algebra are now accessible in <strong class="pkg">GAP</strong> if they are contained in the source files --this information had been ignored in Version 1.0 (see <code class="func">AtlasOfGroupRepresentationsTestTableOfContentsRemoteUpdates</code> (<a href="chap4.html#X7E04B1C57C38DCB2"><span class="RefLink">4.2-4</span></a>) for necessary updates).</p>
<p>Additional information is now available via the internet (see <a href="chap4.html#X876E8147820EABAF"><span class="RefLink">4.4</span></a>).</p>
<p>The update facilities have been extended (see <a href="chap4.html#X7A40921B84F27E68"><span class="RefLink">4.2</span></a>).</p>
<p>The manual is now distributed also in pdf and HTML format; on the other hand, the PostScript format manual is no longer contained in the archives.</p>
<p>Apart from these changes, a few minor bugs in the handling of <strong class="pkg">MeatAxe</strong> files have been fixed, typos in the documentation have been corrected, and the syntax checks for <strong class="pkg">ATLAS</strong> straight line programs (see <a href="chap7.html#X8211B26D841B874C"><span class="RefLink">7.4</span></a>) have been improved.</p>
<p><a id="X82A988D47DFAFCFA" name="X82A988D47DFAFCFA"></a></p>
<h4>1.4 <span class="Heading">Acknowledgements</span></h4>
<ul>
<li><p>Frank Lübeck and Max Neunhöffer kindly provided the perl script that had been used for fetching remote data until version 1.2. Thanks also to Greg Gamble and Alexander Hulpke for technical hints concerning "standard" perl.</p>
</li>
<li><p>Ulrich Kaiser helped with preparing the package for MS Windows.</p>
</li>
<li><p>Klaus Lux had the idea to support private extensions of the package, see Chapter <a href="chap5.html#X7B33345C7B304697"><span class="RefLink">5</span></a> and helped to fix several bugs.</p>
</li>
<li><p>Frank Lübeck contributed the functions <code class="func">CMtxBinaryFFMatOrPerm</code> (<a href="chap7.html#X8477AA668733255C"><span class="RefLink">7.3-4</span></a>) and <code class="func">FFMatOrPermCMtxBinary</code> (<a href="chap7.html#X872FA00C7F791FBB"><span class="RefLink">7.3-5</span></a>).</p>
</li>
<li><p>Frank Lübeck and Max Neunhöffer wrote the <strong class="pkg">GAPDoc</strong> package <a href="chapBib.html#biBGAPDoc">[LN12]</a>, which is used for processing the documentation of the <strong class="pkg">AtlasRep</strong> package and for processing the bibliographies included in this package (see <code class="func">BrowseBibliographySporadicSimple</code> (<a href="chap3.html#X84ED4FC182C28198"><span class="RefLink">3.6-2</span></a>)),</p>
</li>
<li><p>Max Neunhöffer wrote the <strong class="pkg">GAP</strong> package <strong class="pkg">IO</strong> <a href="chapBib.html#biBIO">[Neu14]</a>, which is recommended for transferring data.</p>
</li>
<li><p>Max has also suggested the generalization of the data access described in Section <a href="chap7.html#X81C5B5E78215169D"><span class="RefLink">7.2</span></a>, and the admissibility of the function <code class="func">Character</code> (<a href="../../../doc/ref/chap72.html#X849DD34C7968206C"><span class="RefLink">Reference: Character (for a character table and a list)</span></a>) as a filter in <code class="func">DisplayAtlasInfo</code> (<a href="chap3.html#X79DACFFA7E2D1A99"><span class="RefLink">3.5-1</span></a>), <code class="func">OneAtlasGeneratingSetInfo</code> (<a href="chap3.html#X841478AB7CD06D44"><span class="RefLink">3.5-5</span></a>), and <code class="func">AllAtlasGeneratingSetInfos</code> (<a href="chap3.html#X84C2D76482E60E42"><span class="RefLink">3.5-6</span></a>).</p>
</li>
<li><p>Gunter Malle suggested to make the information about representations of minimal degree accessible, see Section <a href="chap6.html#X87E1F08D80C9E069"><span class="RefLink">6.3</span></a>.</p>
</li>
<li><p>Andries Brouwer suggested to add a tutorial (see Chapter <a href="chap2.html#X8502B3798180E78D"><span class="RefLink">2</span></a>), Klaus Lux suggested several improvements of this chapter.</p>
</li>
</ul>
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