view mayachemtools/docs/modules/html/code/GraphMatrix.html @ 9:ab29fa5c8c1f draft default tip

Uploaded
author deepakjadmin
date Thu, 15 Dec 2016 14:18:03 -0500
parents 73ae111cf86f
children
line wrap: on
line source

<html>
<head>
<title>MayaChemTools:Code:Graph::GraphMatrix.pm</title>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<link rel="stylesheet" type="text/css" href="../../../css/MayaChemToolsCode.css">
</head>
<body leftmargin="20" rightmargin="20" topmargin="10" bottommargin="10">
<br/>
<center>
<a href="http://www.mayachemtools.org" title="MayaChemTools Home"><img src="../../../images/MayaChemToolsLogo.gif" border="0" alt="MayaChemTools"></a>
</center>
<br/>
<pre>
<a name="package-Graph::GraphMatrix-"></a>   1 <span class="k">package </span><span class="i">Graph::GraphMatrix</span><span class="sc">;</span>
   2 <span class="c">#</span>
   3 <span class="c"># $RCSfile: GraphMatrix.pm,v $</span>
   4 <span class="c"># $Date: 2015/02/28 20:49:06 $</span>
   5 <span class="c"># $Revision: 1.17 $</span>
   6 <span class="c">#</span>
   7 <span class="c"># Author: Manish Sud &lt;msud@san.rr.com&gt;</span>
   8 <span class="c">#</span>
   9 <span class="c"># Copyright (C) 2015 Manish Sud. All rights reserved.</span>
  10 <span class="c">#</span>
  11 <span class="c"># This file is part of MayaChemTools.</span>
  12 <span class="c">#</span>
  13 <span class="c"># MayaChemTools is free software; you can redistribute it and/or modify it under</span>
  14 <span class="c"># the terms of the GNU Lesser General Public License as published by the Free</span>
  15 <span class="c"># Software Foundation; either version 3 of the License, or (at your option) any</span>
  16 <span class="c"># later version.</span>
  17 <span class="c">#</span>
  18 <span class="c"># MayaChemTools is distributed in the hope that it will be useful, but without</span>
  19 <span class="c"># any warranty; without even the implied warranty of merchantability of fitness</span>
  20 <span class="c"># for a particular purpose.  See the GNU Lesser General Public License for more</span>
  21 <span class="c"># details.</span>
  22 <span class="c">#</span>
  23 <span class="c"># You should have received a copy of the GNU Lesser General Public License</span>
  24 <span class="c"># along with MayaChemTools; if not, see &lt;http://www.gnu.org/licenses/&gt; or</span>
  25 <span class="c"># write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,</span>
  26 <span class="c"># Boston, MA, 02111-1307, USA.</span>
  27 <span class="c">#</span>
  28 
  29 <span class="k">use</span> <span class="w">strict</span><span class="sc">;</span>
  30 <span class="k">use</span> <span class="w">Carp</span><span class="sc">;</span>
  31 <span class="k">use</span> <span class="w">Exporter</span><span class="sc">;</span>
  32 <span class="k">use</span> <span class="w">Graph</span><span class="sc">;</span>
  33 <span class="k">use</span> <span class="w">Matrix</span><span class="sc">;</span>
  34 <span class="k">use</span> <span class="w">Constants</span><span class="sc">;</span>
  35 
  36 <span class="k">use</span> <span class="w">vars</span> <span class="q">qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS)</span><span class="sc">;</span>
  37 
  38 <span class="i">@ISA</span> = <span class="q">qw(Exporter)</span><span class="sc">;</span>
  39 <span class="i">@EXPORT</span> = <span class="q">qw()</span><span class="sc">;</span>
  40 <span class="i">@EXPORT_OK</span> = <span class="q">qw()</span><span class="sc">;</span>
  41 
  42 <span class="i">%EXPORT_TAGS</span> = <span class="s">(</span><span class="w">all</span>  <span class="cm">=&gt;</span> <span class="s">[</span><span class="i">@EXPORT</span><span class="cm">,</span> <span class="i">@EXPORT_OK</span><span class="s">]</span><span class="s">)</span><span class="sc">;</span>
  43 
  44 <span class="c"># Setup class variables...</span>
  45 <span class="k">my</span><span class="s">(</span><span class="i">$ClassName</span><span class="s">)</span><span class="sc">;</span>
  46 <span class="i">_InitializeClass</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
  47 
  48 <span class="c"># Overload Perl functions...</span>
  49 <span class="k">use</span> <span class="w">overload</span> <span class="q">&#39;&quot;&quot;&#39;</span> <span class="cm">=&gt;</span> <span class="q">&#39;StringifyGraphMatrix&#39;</span><span class="sc">;</span>
  50 
  51 <span class="c"># Class constructor...</span>
<a name="new-"></a>  52 <span class="k">sub </span><span class="m">new</span> <span class="s">{</span>
  53   <span class="k">my</span><span class="s">(</span><span class="i">$Class</span><span class="cm">,</span> <span class="i">$Graph</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
  54 
  55   <span class="c"># Initialize object...</span>
  56   <span class="k">my</span> <span class="i">$This</span> = <span class="s">{</span><span class="s">}</span><span class="sc">;</span>
  57   <span class="k">bless</span> <span class="i">$This</span><span class="cm">,</span> <span class="k">ref</span><span class="s">(</span><span class="i">$Class</span><span class="s">)</span> || <span class="i">$Class</span><span class="sc">;</span>
  58   <span class="i">$This</span><span class="i">-&gt;_InitializeGraphMatrix</span><span class="s">(</span><span class="i">$Graph</span><span class="s">)</span><span class="sc">;</span>
  59 
  60   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
  61 <span class="s">}</span>
  62 
  63 <span class="c"># Initialize object data...</span>
<a name="_InitializeGraphMatrix-"></a>  64 <span class="k">sub </span><span class="m">_InitializeGraphMatrix</span> <span class="s">{</span>
  65   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$Graph</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
  66 
  67   <span class="c"># Specified graph object...</span>
  68   <span class="i">$This</span>-&gt;{<span class="w">Graph</span>} = <span class="i">$Graph</span><span class="sc">;</span>
  69 
  70   <span class="c"># Generated matrix...</span>
  71   <span class="i">$This</span>-&gt;{<span class="w">Matrix</span>} = <span class="k">undef</span><span class="sc">;</span>
  72   <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>} = <span class="k">undef</span><span class="sc">;</span>
  73 
  74   <span class="c"># Row and columns IDs...</span>
  75   <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">RowIDs</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
  76   <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
  77 
  78   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
  79 <span class="s">}</span>
  80 
  81 <span class="c"># Initialize class ...</span>
<a name="_InitializeClass-"></a>  82 <span class="k">sub </span><span class="m">_InitializeClass</span> <span class="s">{</span>
  83   <span class="c">#Class name...</span>
  84   <span class="i">$ClassName</span> = <span class="w">__PACKAGE__</span><span class="sc">;</span>
  85 <span class="s">}</span>
  86 
  87 <span class="c"># Generate the adjacency matrix for a simple graph.</span>
  88 <span class="c">#</span>
  89 <span class="c"># For a simple graph G with n vertices, the adjacency matrix for G is a n x n square matrix and</span>
  90 <span class="c"># its elements Mij are:</span>
  91 <span class="c">#</span>
  92 <span class="c">#   . 0    if i == j</span>
  93 <span class="c">#   . 1    if i != j and vertex Vi is adjacent to vertex Vj</span>
  94 <span class="c">#   . 0    if i != j and vertex Vi is not adjacent to vertex Vj</span>
  95 <span class="c">#</span>
<a name="GenerateAdjacencyMatrix-"></a>  96 <span class="k">sub </span><span class="m">GenerateAdjacencyMatrix</span> <span class="s">{</span>
  97   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
  98   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
  99 
 100   <span class="c"># Get graph vertices...</span>
 101   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 102   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 103   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 104 
 105   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 106     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateAdjacencyMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 107     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 108   <span class="s">}</span>
 109 
 110   <span class="c"># Create adjacency matrix...</span>
 111   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 112 
 113   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 114   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 115 
 116   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 117     <span class="i">$RowVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 118     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 119       <span class="i">$ColVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$ColIndex</span>]<span class="sc">;</span>
 120       <span class="i">$Value</span> = <span class="s">(</span><span class="i">$RowIndex</span> == <span class="i">$ColIndex</span><span class="s">)</span> ? <span class="n">0</span> <span class="co">:</span> <span class="s">(</span><span class="i">$Graph</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="n">0</span><span class="s">)</span><span class="sc">;</span>
 121       <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 122     <span class="s">}</span>
 123   <span class="s">}</span>
 124   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;AdjacencyMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 125 
 126   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 127 <span class="s">}</span>
 128 
 129 <span class="c"># Generate the Siedel adjacency matrix for a simple graph.</span>
 130 <span class="c">#</span>
 131 <span class="c"># For a simple graph G with n vertices, the Siedal adjacency matrix for G is a n x n square matrix and</span>
 132 <span class="c"># its elements Mij are:</span>
 133 <span class="c">#</span>
 134 <span class="c">#   . 0    if i == j</span>
 135 <span class="c">#   . -1   if i != j and vertex Vi is adjacent to vertex Vj</span>
 136 <span class="c">#   . 1    if i != j and vertex Vi is not adjacent to vertex Vj</span>
 137 <span class="c">#</span>
<a name="GenerateSiedelAdjacencyMatrix-"></a> 138 <span class="k">sub </span><span class="m">GenerateSiedelAdjacencyMatrix</span> <span class="s">{</span>
 139   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 140   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 141 
 142   <span class="c"># Get graph vertices...</span>
 143   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 144   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 145   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 146 
 147   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 148     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateSiedelAdjacencyMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 149     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 150   <span class="s">}</span>
 151 
 152   <span class="c"># Create Siedel adjacency matrix...</span>
 153   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 154 
 155   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 156   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 157 
 158   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 159     <span class="i">$RowVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 160     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 161       <span class="i">$ColVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$ColIndex</span>]<span class="sc">;</span>
 162       <span class="i">$Value</span> = <span class="s">(</span><span class="i">$RowIndex</span> == <span class="i">$ColIndex</span><span class="s">)</span> ? <span class="n">0</span> <span class="co">:</span> <span class="s">(</span><span class="i">$Graph</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="s">)</span> ? <span class="n">-1</span> <span class="co">:</span> <span class="n">1</span><span class="s">)</span><span class="sc">;</span>
 163       <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 164     <span class="s">}</span>
 165   <span class="s">}</span>
 166   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;SiedelAdjacencyMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 167 
 168   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 169 <span class="s">}</span>
 170 
 171 <span class="c"># Generate distance matrix for a simple graph using Floyd-Marshall algorithm [Ref 67].</span>
 172 <span class="c">#</span>
 173 <span class="c"># For a simple graph G with n vertices, the distance matrix for G is a n x n square matrix and</span>
 174 <span class="c"># its elements Mij are:</span>
 175 <span class="c">#</span>
 176 <span class="c">#   . 0    if i == j</span>
 177 <span class="c">#   . d    if i != j and d is the shortest distance between vertex Vi and vertex Vj</span>
 178 <span class="c">#</span>
 179 <span class="c"># Note:</span>
 180 <span class="c">#   . In the final matrix, BigNumber values correspond to vertices with no edges.</span>
 181 <span class="c">#</span>
<a name="GenerateDistanceMatrix-"></a> 182 <span class="k">sub </span><span class="m">GenerateDistanceMatrix</span> <span class="s">{</span>
 183   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 184   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 185 
 186   <span class="c"># Get graph vertices...</span>
 187   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 188   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 189   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 190 
 191   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 192     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateDistanceMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 193     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 194   <span class="s">}</span>
 195 
 196   <span class="c"># Initialize matrix...</span>
 197   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$MatrixValuesRef</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="cm">,</span> <span class="i">$Value</span><span class="s">)</span><span class="sc">;</span>
 198 
 199   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 200   <span class="i">$MatrixValuesRef</span> = <span class="i">$Matrix</span><span class="i">-&gt;GetMatrixValuesReference</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 201 
 202   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 203     <span class="i">$RowVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 204     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 205       <span class="i">$ColVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$ColIndex</span>]<span class="sc">;</span>
 206       <span class="i">$Value</span> = <span class="s">(</span><span class="i">$RowIndex</span> == <span class="i">$ColIndex</span><span class="s">)</span> ? <span class="n">0</span> <span class="co">:</span> <span class="s">(</span><span class="i">$Graph</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="w">BigNumber</span><span class="s">)</span><span class="sc">;</span>
 207       <span class="i">$MatrixValuesRef</span>-&gt;[<span class="i">$RowIndex</span>][<span class="i">$ColIndex</span>] = <span class="i">$Value</span><span class="sc">;</span>
 208     <span class="s">}</span>
 209   <span class="s">}</span>
 210 
 211   <span class="c"># Create distance matrix...</span>
 212   <span class="k">my</span><span class="s">(</span><span class="i">$i</span><span class="cm">,</span> <span class="i">$j</span><span class="cm">,</span> <span class="i">$k</span><span class="cm">,</span> <span class="i">$Valuejk</span><span class="s">)</span><span class="sc">;</span>
 213 
 214   <span class="k">for</span> <span class="i">$i</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 215     <span class="k">for</span> <span class="i">$j</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 216       <span class="k">for</span> <span class="i">$k</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 217         <span class="i">$Valuejk</span> = <span class="i">$MatrixValuesRef</span>-&gt;[<span class="i">$j</span>][<span class="i">$i</span>] + <span class="i">$MatrixValuesRef</span>-&gt;[<span class="i">$i</span>][<span class="i">$k</span>]<span class="sc">;</span>
 218         <span class="k">if</span> <span class="s">(</span><span class="i">$Valuejk</span> &lt; <span class="i">$MatrixValuesRef</span>-&gt;[<span class="i">$j</span>][<span class="i">$k</span>]<span class="s">)</span> <span class="s">{</span>
 219           <span class="i">$MatrixValuesRef</span>-&gt;[<span class="i">$j</span>][<span class="i">$k</span>] = <span class="i">$Valuejk</span><span class="sc">;</span>
 220         <span class="s">}</span>
 221       <span class="s">}</span>
 222     <span class="s">}</span>
 223   <span class="s">}</span>
 224   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;DistanceMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 225 
 226   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 227 <span class="s">}</span>
 228 
 229 <span class="c"># Generate the incidence matrix for a simple graph.</span>
 230 <span class="c">#</span>
 231 <span class="c"># For a simple graph G with n vertices and e edges, the incidence matrix for G is a n x e matrix</span>
 232 <span class="c"># its elements Mij are:</span>
 233 <span class="c">#</span>
 234 <span class="c">#   . 1    if vertex Vi and the edge Ej are incident; in other words, Vi and Ej are related</span>
 235 <span class="c">#   . 0    otherwise</span>
 236 <span class="c">#</span>
<a name="GenerateIncidenceMatrix-"></a> 237 <span class="k">sub </span><span class="m">GenerateIncidenceMatrix</span> <span class="s">{</span>
 238   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 239   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfEdges</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="cm">,</span> <span class="i">@EdgeVertexIDs</span><span class="s">)</span><span class="sc">;</span>
 240 
 241   <span class="c"># Get graph vertices and edges...</span>
 242   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 243   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 244   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 245 
 246   <span class="i">@EdgeVertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetEdges</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 247   <span class="i">$NumOfEdges</span> = <span class="i">@EdgeVertexIDs</span>/<span class="n">2</span><span class="sc">;</span>
 248 
 249   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 250     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateIncidenceMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 251     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 252   <span class="s">}</span>
 253 
 254   <span class="c"># Create incidence matrix...</span>
 255   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$EdgeVertexIndex</span><span class="cm">,</span> <span class="i">$VertexID</span><span class="cm">,</span> <span class="i">$EdgeVertexID1</span><span class="cm">,</span> <span class="i">$EdgeVertexID2</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 256 
 257   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfEdges</span><span class="s">)</span><span class="sc">;</span>
 258 
 259   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 260   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 261     <span class="i">$VertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 262     <span class="i">$EdgeVertexIndex</span> = <span class="n">0</span><span class="sc">;</span>
 263     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfEdges</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 264       <span class="i">$EdgeVertexID1</span> = <span class="i">$EdgeVertexIDs</span>[<span class="i">$EdgeVertexIndex</span>]<span class="sc">;</span> <span class="i">$EdgeVertexIndex</span>++<span class="sc">;</span>
 265       <span class="i">$EdgeVertexID2</span> = <span class="i">$EdgeVertexIDs</span>[<span class="i">$EdgeVertexIndex</span>]<span class="sc">;</span> <span class="i">$EdgeVertexIndex</span>++<span class="sc">;</span>
 266 
 267       <span class="i">$Value</span> = <span class="s">(</span><span class="i">$VertexID</span> == <span class="i">$EdgeVertexID1</span> || <span class="i">$VertexID</span> == <span class="i">$EdgeVertexID2</span><span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="n">0</span><span class="sc">;</span>
 268       <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 269     <span class="s">}</span>
 270   <span class="s">}</span>
 271   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;IncidenceMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="cm">,</span> \<span class="i">@EdgeVertexIDs</span><span class="s">)</span><span class="sc">;</span>
 272 
 273   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 274 <span class="s">}</span>
 275 
 276 <span class="c"># Generate the degree matrix for a simple graph.</span>
 277 <span class="c">#</span>
 278 <span class="c"># For a simple graph G with n vertices, the degree matrix for G is a n x n square matrix and</span>
 279 <span class="c"># its elements Mij are:</span>
 280 <span class="c">#</span>
 281 <span class="c">#   . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi</span>
 282 <span class="c">#   . 0         otherwise</span>
 283 <span class="c">#</span>
<a name="GenerateDegreeMatrix-"></a> 284 <span class="k">sub </span><span class="m">GenerateDegreeMatrix</span> <span class="s">{</span>
 285   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 286   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 287 
 288   <span class="c"># Get graph vertices...</span>
 289   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 290   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 291   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 292 
 293   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 294     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateDegreeMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 295     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 296   <span class="s">}</span>
 297 
 298   <span class="c"># Create degree matrix...</span>
 299   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$Index</span><span class="cm">,</span> <span class="i">$VertexID</span><span class="cm">,</span> <span class="i">$Degree</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 300 
 301   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 302   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 303 
 304   <span class="k">for</span> <span class="i">$Index</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 305     <span class="i">$VertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$Index</span>]<span class="sc">;</span>
 306     <span class="i">$Degree</span> = <span class="i">$Graph</span><span class="i">-&gt;GetDegree</span><span class="s">(</span><span class="i">$VertexID</span><span class="s">)</span><span class="sc">;</span>
 307     <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$Index</span><span class="cm">,</span> <span class="i">$Index</span><span class="cm">,</span> <span class="i">$Degree</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 308   <span class="s">}</span>
 309   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;DegreeMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 310 
 311   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 312 <span class="s">}</span>
 313 
 314 <span class="c"># Generate the Laplacian matrix for a simple graph.</span>
 315 <span class="c">#</span>
 316 <span class="c"># For a simple graph G with n vertices, the Laplacian matrix for G is a n x n square matrix and</span>
 317 <span class="c"># its elements Mij are:</span>
 318 <span class="c">#</span>
 319 <span class="c">#   . deg(Vi)   if i == j and deg(Vi) is the degree of vertex Vi</span>
 320 <span class="c">#   . -1        if i != j and vertex Vi is adjacent to vertex Vj</span>
 321 <span class="c">#   . 0         otherwise</span>
 322 <span class="c">#</span>
 323 <span class="c"># Note: The Laplacian matrix is the difference between the degree matrix and adjacency matrix.</span>
 324 <span class="c">#</span>
<a name="GenerateLaplacianMatrix-"></a> 325 <span class="k">sub </span><span class="m">GenerateLaplacianMatrix</span> <span class="s">{</span>
 326   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 327   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 328 
 329   <span class="c"># Get graph vertices...</span>
 330   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 331   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 332   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 333 
 334   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 335     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateLaplacianMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 336     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 337   <span class="s">}</span>
 338 
 339   <span class="c"># Create adjacency matrix...</span>
 340   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 341 
 342   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 343   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 344 
 345   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 346     <span class="i">$RowVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 347     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 348       <span class="i">$ColVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$ColIndex</span>]<span class="sc">;</span>
 349       <span class="i">$Value</span> = <span class="s">(</span><span class="i">$RowIndex</span> == <span class="i">$ColIndex</span><span class="s">)</span> ? <span class="i">$Graph</span><span class="i">-&gt;GetDegree</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="s">)</span> <span class="co">:</span> <span class="s">(</span><span class="i">$Graph</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="s">)</span> ? <span class="n">-1</span> <span class="co">:</span> <span class="n">0</span><span class="s">)</span><span class="sc">;</span>
 350       <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 351     <span class="s">}</span>
 352   <span class="s">}</span>
 353   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;LaplacianMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 354 
 355   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 356 <span class="s">}</span>
 357 
 358 <span class="c"># Generate the normalized Laplacian matrix for a simple graph.</span>
 359 <span class="c">#</span>
 360 <span class="c"># For a simple graph G with n vertices, the normalized Laplacian matrix L for G is a n x n square matrix and</span>
 361 <span class="c"># its elements Lij are:</span>
 362 <span class="c">#</span>
 363 <span class="c">#   . 1                           if i == j and deg(Vi) != 0</span>
 364 <span class="c">#   . -1/SQRT(deg(Vi) * deg(Vj))  if i != j and vertex Vi is adjacent to vertex Vj</span>
 365 <span class="c">#   . 0                           otherwise</span>
 366 <span class="c">#</span>
 367 <span class="c">#</span>
<a name="GenerateNormalizedLaplacianMatrix-"></a> 368 <span class="k">sub </span><span class="m">GenerateNormalizedLaplacianMatrix</span> <span class="s">{</span>
 369   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 370   <span class="k">my</span><span class="s">(</span><span class="i">$Graph</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 371 
 372   <span class="c"># Get graph vertices...</span>
 373   <span class="i">$Graph</span> = <span class="i">$This</span>-&gt;{<span class="w">Graph</span>}<span class="sc">;</span>
 374   <span class="i">@VertexIDs</span> = <span class="i">$Graph</span><span class="i">-&gt;GetVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 375   <span class="i">$NumOfVertices</span> = <span class="k">scalar</span> <span class="i">@VertexIDs</span><span class="sc">;</span>
 376 
 377   <span class="k">if</span> <span class="s">(</span><span class="i">$NumOfVertices</span> == <span class="n">0</span><span class="s">)</span> <span class="s">{</span>
 378     <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;GenerateNormalizedLaplacianMatrix: Specified graph doesn&#39;t contain any vertices: No matrix generated...&quot;</span><span class="sc">;</span>
 379     <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 380   <span class="s">}</span>
 381 
 382   <span class="c"># Create adjacency matrix...</span>
 383   <span class="k">my</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="cm">,</span> <span class="i">$RowVertexDegree</span><span class="cm">,</span> <span class="i">$ColVertexDegree</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 384 
 385   <span class="i">$Matrix</span> = <span class="i">new</span> <span class="i">Matrix</span><span class="s">(</span><span class="i">$NumOfVertices</span><span class="cm">,</span> <span class="i">$NumOfVertices</span><span class="s">)</span><span class="sc">;</span>
 386   <span class="i">$SkipIndexCheck</span> = <span class="n">1</span><span class="sc">;</span>
 387 
 388   <span class="k">for</span> <span class="i">$RowIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 389     <span class="i">$RowVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$RowIndex</span>]<span class="sc">;</span>
 390     <span class="i">$RowVertexDegree</span> = <span class="i">$Graph</span><span class="i">-&gt;GetDegree</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="s">)</span><span class="sc">;</span>
 391     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfVertices</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 392       <span class="i">$ColVertexID</span> = <span class="i">$VertexIDs</span>[<span class="i">$ColIndex</span>]<span class="sc">;</span>
 393       <span class="i">$Value</span> = <span class="n">0</span><span class="sc">;</span>
 394       <span class="k">if</span> <span class="s">(</span><span class="i">$RowIndex</span> == <span class="i">$ColIndex</span><span class="s">)</span> <span class="s">{</span>
 395         <span class="i">$Value</span> = <span class="s">(</span><span class="i">$RowVertexDegree</span> == <span class="n">0</span><span class="s">)</span> ? <span class="n">0</span> <span class="co">:</span> <span class="n">1</span><span class="sc">;</span>
 396       <span class="s">}</span>
 397       <span class="k">else</span> <span class="s">{</span>
 398         <span class="i">$ColVertexDegree</span> = <span class="i">$Graph</span><span class="i">-&gt;GetDegree</span><span class="s">(</span><span class="i">$ColVertexID</span><span class="s">)</span><span class="sc">;</span>
 399         <span class="i">$Value</span> = <span class="i">$Graph</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$RowVertexID</span><span class="cm">,</span> <span class="i">$ColVertexID</span><span class="s">)</span> ? <span class="s">(</span><span class="n">-1</span>/<span class="k">sqrt</span><span class="s">(</span><span class="i">$RowVertexDegree</span> * <span class="i">$ColVertexDegree</span><span class="s">)</span><span class="s">)</span> <span class="co">:</span> <span class="n">0</span><span class="sc">;</span>
 400       <span class="s">}</span>
 401       <span class="i">$Matrix</span><span class="i">-&gt;SetValue</span><span class="s">(</span><span class="i">$RowIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$Value</span><span class="cm">,</span> <span class="i">$SkipIndexCheck</span><span class="s">)</span><span class="sc">;</span>
 402     <span class="s">}</span>
 403   <span class="s">}</span>
 404   <span class="i">$This</span><span class="i">-&gt;_SetMatrixAndAssociatedInformation</span><span class="s">(</span><span class="i">$Matrix</span><span class="cm">,</span> <span class="q">&quot;NormalizedLaplacianMatrix&quot;</span><span class="cm">,</span> \<span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
 405 
 406   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 407 <span class="s">}</span>
 408 
 409 <span class="c"># Generate the admittance matrix for a simple graph.</span>
 410 <span class="c">#</span>
<a name="GenerateAdmittanceMatrix-"></a> 411 <span class="k">sub </span><span class="m">GenerateAdmittanceMatrix</span> <span class="s">{</span>
 412   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 413 
 414   <span class="i">$This</span><span class="i">-&gt;GenerateLaplacianMatrix</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 415   <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>} = <span class="q">&quot;AdmittanceMatrix&quot;</span><span class="sc">;</span>
 416 
 417   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 418 <span class="s">}</span>
 419 
 420 <span class="c"># Generate the Kirchhoff matrix for a simple graph.</span>
 421 <span class="c">#</span>
<a name="GenerateKirchhoffMatrix-"></a> 422 <span class="k">sub </span><span class="m">GenerateKirchhoffMatrix</span> <span class="s">{</span>
 423   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 424 
 425   <span class="i">$This</span><span class="i">-&gt;GenerateLaplacianMatrix</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 426   <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>} = <span class="q">&quot;KirchhoffMatrix&quot;</span><span class="sc">;</span>
 427 
 428   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 429 <span class="s">}</span>
 430 
 431 <span class="c"># Get generated matrix...</span>
 432 <span class="c">#</span>
<a name="GetMatrix-"></a> 433 <span class="k">sub </span><span class="m">GetMatrix</span> <span class="s">{</span>
 434   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 435 
 436   <span class="k">return</span> <span class="i">$This</span>-&gt;{<span class="w">Matrix</span>}<span class="sc">;</span>
 437 <span class="s">}</span>
 438 
 439 <span class="c"># Get matrix type...</span>
 440 <span class="c">#</span>
<a name="GetMatrixType-"></a> 441 <span class="k">sub </span><span class="m">GetMatrixType</span> <span class="s">{</span>
 442   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 443 
 444   <span class="k">return</span> <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>}<span class="sc">;</span>
 445 <span class="s">}</span>
 446 
 447 <span class="c"># Get row IDs...</span>
 448 <span class="c">#</span>
<a name="GetRowIDs-"></a> 449 <span class="k">sub </span><span class="m">GetRowIDs</span> <span class="s">{</span>
 450   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 451 
 452   <span class="k">return</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">RowIDs</span>}}<span class="sc">;</span>
 453 <span class="s">}</span>
 454 
 455 <span class="c"># Get column IDs...</span>
 456 <span class="c">#</span>
<a name="GetColumnIDs-"></a> 457 <span class="k">sub </span><span class="m">GetColumnIDs</span> <span class="s">{</span>
 458   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 459 
 460   <span class="k">return</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}}<span class="sc">;</span>
 461 <span class="s">}</span>
 462 
 463 
 464 <span class="c"># Setup matrix and other associated information...</span>
 465 <span class="c">#</span>
<a name="_SetMatrixAndAssociatedInformation-"></a> 466 <span class="k">sub </span><span class="m">_SetMatrixAndAssociatedInformation</span> <span class="s">{</span>
 467   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$Matrix</span><span class="cm">,</span> <span class="i">$MatrixType</span><span class="cm">,</span> <span class="i">$VertexIDsRef</span><span class="cm">,</span> <span class="i">$EdgeVertexIDsRef</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 468 
 469   <span class="i">$This</span>-&gt;{<span class="w">Matrix</span>} = <span class="i">$Matrix</span><span class="sc">;</span>
 470   <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>} = <span class="i">$MatrixType</span><span class="sc">;</span>
 471 
 472   <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">RowIDs</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 473   <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}} = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
 474 
 475   <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">RowIDs</span>}} = <span class="i">@</span>{<span class="i">$VertexIDsRef</span>}<span class="sc">;</span>
 476 
 477   <span class="k">if</span> <span class="s">(</span><span class="i">$MatrixType</span> =~ <span class="q">/^IncidenceMatrix$/i</span><span class="s">)</span> <span class="s">{</span>
 478     <span class="c"># Setup column IDs using edge vertex IDs...</span>
 479     <span class="k">my</span><span class="s">(</span><span class="i">$NumOfEdges</span><span class="cm">,</span> <span class="i">$EdgeVertexIndex</span><span class="cm">,</span> <span class="i">$ColIndex</span><span class="cm">,</span> <span class="i">$EdgeVertexID1</span><span class="cm">,</span> <span class="i">$EdgeVertexID2</span><span class="cm">,</span> <span class="i">$EdgeID</span><span class="s">)</span><span class="sc">;</span>
 480 
 481     <span class="i">$NumOfEdges</span> = <span class="s">(</span><span class="k">scalar</span> <span class="i">@</span>{<span class="i">$EdgeVertexIDsRef</span>}<span class="s">)</span>/<span class="n">2</span><span class="sc">;</span>
 482     <span class="i">$EdgeVertexIndex</span> = <span class="n">0</span><span class="sc">;</span>
 483 
 484     <span class="k">for</span> <span class="i">$ColIndex</span> <span class="s">(</span><span class="n">0</span> .. <span class="s">(</span><span class="i">$NumOfEdges</span> - <span class="n">1</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
 485       <span class="i">$EdgeVertexID1</span> = <span class="i">$EdgeVertexIDsRef</span>-&gt;[<span class="i">$EdgeVertexIndex</span>]<span class="sc">;</span> <span class="i">$EdgeVertexIndex</span>++<span class="sc">;</span>
 486       <span class="i">$EdgeVertexID2</span> = <span class="i">$EdgeVertexIDsRef</span>-&gt;[<span class="i">$EdgeVertexIndex</span>]<span class="sc">;</span> <span class="i">$EdgeVertexIndex</span>++<span class="sc">;</span>
 487       <span class="i">$EdgeID</span> = <span class="s">(</span><span class="i">$EdgeVertexID1</span> &lt; <span class="i">$EdgeVertexID2</span><span class="s">)</span> ? <span class="q">&quot;${EdgeVertexID1}-${EdgeVertexID2}&quot;</span> <span class="co">:</span> <span class="q">&quot;${EdgeVertexID2}-${EdgeVertexID1}&quot;</span><span class="sc">;</span>
 488 
 489       <span class="k">push</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}}<span class="cm">,</span> <span class="i">$EdgeID</span><span class="sc">;</span>
 490     <span class="s">}</span>
 491   <span class="s">}</span>
 492   <span class="k">else</span> <span class="s">{</span>
 493     <span class="k">push</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}}<span class="cm">,</span> <span class="i">@</span>{<span class="i">$VertexIDsRef</span>}<span class="sc">;</span>
 494   <span class="s">}</span>
 495   <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
 496 <span class="s">}</span>
 497 
 498 <span class="c"># Return a string containg data for GraphMatrix object...</span>
<a name="StringifyGraphMatrix-"></a> 499 <span class="k">sub </span><span class="m">StringifyGraphMatrix</span> <span class="s">{</span>
 500   <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
 501   <span class="k">my</span><span class="s">(</span><span class="i">$GraphMatrixString</span><span class="cm">,</span> <span class="i">$RowIDs</span><span class="s">)</span><span class="sc">;</span>
 502 
 503   <span class="i">$GraphMatrixString</span> = <span class="q">&quot;GraphMatrix:&quot;</span><span class="sc">;</span>
 504 
 505   <span class="i">$GraphMatrixString</span> .= <span class="s">(</span><span class="k">defined</span> <span class="i">$This</span>-&gt;{<span class="w">MatrixType</span>}<span class="s">)</span> ? <span class="q">&quot; MatrixType: $This-&gt;{MatrixType}&quot;</span> <span class="co">:</span> <span class="q">&quot;MatrixType: &lt;Undefined&gt;&quot;</span><span class="sc">;</span>
 506   <span class="i">$GraphMatrixString</span> .= <span class="s">(</span><span class="k">scalar</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">RowIDs</span>}}<span class="s">)</span> ? <span class="q">&quot;; RowIDs: @{$This-&gt;{RowIDs}}&quot;</span> <span class="co">:</span> <span class="q">&quot;; RowIDs: &lt;Undefined&gt;&quot;</span><span class="sc">;</span>
 507   <span class="i">$GraphMatrixString</span> .= <span class="s">(</span><span class="k">scalar</span> <span class="i">@</span>{<span class="i">$This</span>-&gt;{<span class="w">ColumnIDs</span>}}<span class="s">)</span> ? <span class="q">&quot;; ColumnIDs: @{$This-&gt;{ColumnIDs}}&quot;</span> <span class="co">:</span> <span class="q">&quot;; ColumnIDs: &lt;Undefined&gt;&quot;</span><span class="sc">;</span>
 508 
 509   <span class="i">$GraphMatrixString</span> .= <span class="s">(</span><span class="k">defined</span> <span class="i">$This</span>-&gt;{<span class="w">Matrix</span>}<span class="s">)</span> ? <span class="q">&quot;; Matrix: $This-&gt;{Matrix}&quot;</span> <span class="co">:</span> <span class="q">&quot;; Matrix: &lt;Undefined&gt;&quot;</span><span class="sc">;</span>
 510 
 511   <span class="k">return</span> <span class="i">$GraphMatrixString</span><span class="sc">;</span>
 512 <span class="s">}</span>
 513 
<a name="EOF-"></a></pre>
<p>&nbsp;</p>
<br />
<center>
<img src="../../../images/h2o2.png">
</center>
</body>
</html>