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14 <a name="package-Graph::PathGraph-"></a> 1 <span class="k">package </span><span class="i">Graph::PathGraph</span><span class="sc">;</span>
15 2 <span class="c">#</span>
16 3 <span class="c"># $RCSfile: PathGraph.pm,v $</span>
17 4 <span class="c"># $Date: 2015/02/28 20:49:06 $</span>
18 5 <span class="c"># $Revision: 1.24 $</span>
19 6 <span class="c">#</span>
20 7 <span class="c"># Author: Manish Sud &lt;msud@san.rr.com&gt;</span>
21 8 <span class="c">#</span>
22 9 <span class="c"># Copyright (C) 2015 Manish Sud. All rights reserved.</span>
23 10 <span class="c">#</span>
24 11 <span class="c"># This file is part of MayaChemTools.</span>
25 12 <span class="c">#</span>
26 13 <span class="c"># MayaChemTools is free software; you can redistribute it and/or modify it under</span>
27 14 <span class="c"># the terms of the GNU Lesser General Public License as published by the Free</span>
28 15 <span class="c"># Software Foundation; either version 3 of the License, or (at your option) any</span>
29 16 <span class="c"># later version.</span>
30 17 <span class="c">#</span>
31 18 <span class="c"># MayaChemTools is distributed in the hope that it will be useful, but without</span>
32 19 <span class="c"># any warranty; without even the implied warranty of merchantability of fitness</span>
33 20 <span class="c"># for a particular purpose. See the GNU Lesser General Public License for more</span>
34 21 <span class="c"># details.</span>
35 22 <span class="c">#</span>
36 23 <span class="c"># You should have received a copy of the GNU Lesser General Public License</span>
37 24 <span class="c"># along with MayaChemTools; if not, see &lt;http://www.gnu.org/licenses/&gt; or</span>
38 25 <span class="c"># write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,</span>
39 26 <span class="c"># Boston, MA, 02111-1307, USA.</span>
40 27 <span class="c">#</span>
41 28
42 29 <span class="k">use</span> <span class="w">strict</span><span class="sc">;</span>
43 30 <span class="k">use</span> <span class="w">Carp</span><span class="sc">;</span>
44 31 <span class="k">use</span> <span class="w">Exporter</span><span class="sc">;</span>
45 32 <span class="k">use</span> <span class="w">Storable</span> <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
46 33 <span class="k">use</span> <span class="w">Scalar::Util</span> <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
47 34 <span class="k">use</span> <span class="w">Graph</span><span class="sc">;</span>
48 35 <span class="k">use</span> <span class="w">Graph::Path</span><span class="sc">;</span>
49 36
50 37 <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>
51 38
52 39 <span class="i">@ISA</span> = <span class="q">qw(Graph Exporter)</span><span class="sc">;</span>
53 40 <span class="i">@EXPORT</span> = <span class="q">qw(IsPathGraph)</span><span class="sc">;</span>
54 41 <span class="i">@EXPORT_OK</span> = <span class="q">qw()</span><span class="sc">;</span>
55 42
56 43 <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>
57 44
58 45 <span class="c"># Setup class variables...</span>
59 46 <span class="k">my</span><span class="s">(</span><span class="i">$ClassName</span><span class="cm">,</span> <span class="i">$PathsPropertyName</span><span class="cm">,</span> <span class="i">$CyclicPathsPropertyName</span><span class="s">)</span><span class="sc">;</span>
60 47 <span class="i">_InitializeClass</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
61 48
62 49 <span class="c"># Overload Perl functions...</span>
63 50 <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;StringifyPathGraph&#39;</span><span class="sc">;</span>
64 51
65 52 <span class="c"># Class constructor...</span>
66 <a name="new-"></a> 53 <span class="k">sub </span><span class="m">new</span> <span class="s">{</span>
67 54 <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>
68 55
69 56 <span class="c"># Initialize object...</span>
70 57 <span class="k">my</span> <span class="i">$This</span> = <span class="i">$Class</span><span class="i">-&gt;SUPER::new</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
71 58 <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">$Class</span><span class="sc">;</span>
72 59 <span class="i">$This</span><span class="i">-&gt;_InitializePathGraph</span><span class="s">(</span><span class="i">$Graph</span><span class="s">)</span><span class="sc">;</span>
73 60
74 61 <span class="i">$This</span><span class="i">-&gt;_ConvertGraphIntoPathGraph</span><span class="s">(</span><span class="i">$Graph</span><span class="s">)</span><span class="sc">;</span>
75 62
76 63 <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
77 64 <span class="s">}</span>
78 65
79 66 <span class="c"># Initialize object data...</span>
80 <a name="_InitializePathGraph-"></a> 67 <span class="k">sub </span><span class="m">_InitializePathGraph</span> <span class="s">{</span>
81 68 <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>
82 69
83 70 <span class="k">if</span> <span class="s">(</span>!<span class="s">(</span><span class="k">defined</span><span class="s">(</span><span class="i">$Graph</span><span class="s">)</span> &amp;&amp; <span class="i">Graph::IsGraph</span><span class="s">(</span><span class="i">$Graph</span><span class="s">)</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
84 71 <span class="w">croak</span> <span class="q">&quot;Error: ${ClassName}-&gt;new: PathGraph object can&#39;t be instantiated without a Graph object...&quot;</span><span class="sc">;</span>
85 72 <span class="s">}</span>
86 73
87 74 <span class="i">$This</span>-&gt;{<span class="w">Graph</span>} = <span class="i">$Graph</span><span class="sc">;</span>
88 75
89 76 <span class="c"># Maximum time allowed for cycles detection during collapse vertex cycles detection</span>
90 77 <span class="c"># methodology in seconds...</span>
91 78 <span class="i">$This</span>-&gt;{<span class="w">MaxAllowedTime</span>} = <span class="n">30</span><span class="sc">;</span>
92 79
93 80 <span class="c"># Starting time for cycles detection during collapse vertex cycles detection</span>
94 81 <span class="c"># methodology...</span>
95 82 <span class="i">$This</span>-&gt;{<span class="w">StartTime</span>} = <span class="k">time</span><span class="sc">;</span>
96 83
97 84 <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
98 85 <span class="s">}</span>
99 86
100 87 <span class="c"># Initialize class ...</span>
101 <a name="_InitializeClass-"></a> 88 <span class="k">sub </span><span class="m">_InitializeClass</span> <span class="s">{</span>
102 89 <span class="c">#Class name...</span>
103 90 <span class="i">$ClassName</span> = <span class="w">__PACKAGE__</span><span class="sc">;</span>
104 91
105 92 <span class="c"># Path edge property name...</span>
106 93 <span class="i">$PathsPropertyName</span> = <span class="q">&#39;Paths&#39;</span><span class="sc">;</span>
107 94
108 95 <span class="c"># Cyclic path vertex property name...</span>
109 96 <span class="i">$CyclicPathsPropertyName</span> = <span class="q">&#39;CyclicPaths&#39;</span><span class="sc">;</span>
110 97 <span class="s">}</span>
111 98
112 99 <span class="c"># Convert graph into a path graph...</span>
113 100 <span class="c">#</span>
114 <a name="_ConvertGraphIntoPathGraph-"></a> 101 <span class="k">sub </span><span class="m">_ConvertGraphIntoPathGraph</span> <span class="s">{</span>
115 102 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$Graph</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
116 103
117 104 <span class="c"># Copy graph vertices and edges without any associated properties data</span>
118 105 <span class="c"># from Graph to This: Graph properties data is available using Graph object reference</span>
119 106 <span class="c"># store in This object...</span>
120 107 <span class="c">#</span>
121 108 <span class="i">$Graph</span><span class="i">-&gt;CopyVerticesAndEdges</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span><span class="sc">;</span>
122 109
123 110 <span class="c"># . Attach Path property to each edge...</span>
124 111 <span class="c">#</span>
125 112 <span class="k">my</span><span class="s">(</span><span class="i">$Index</span><span class="cm">,</span> <span class="i">$VertexID1</span><span class="cm">,</span> <span class="i">$VertexID2</span><span class="cm">,</span> <span class="i">$Path</span><span class="cm">,</span> <span class="i">@EdgesVertexIDs</span><span class="s">)</span><span class="sc">;</span>
126 113
127 114 <span class="i">@EdgesVertexIDs</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
128 115 <span class="i">@EdgesVertexIDs</span> = <span class="i">$This</span><span class="i">-&gt;GetEdges</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
129 116 <span class="k">for</span> <span class="s">(</span><span class="i">$Index</span> = <span class="n">0</span><span class="sc">;</span> <span class="i">$Index</span> &lt; <span class="i">$#EdgesVertexIDs</span><span class="sc">;</span> <span class="i">$Index</span> += <span class="n">2</span><span class="s">)</span> <span class="s">{</span>
130 117 <span class="i">$VertexID1</span> = <span class="i">$EdgesVertexIDs</span>[<span class="i">$Index</span>]<span class="sc">;</span> <span class="i">$VertexID2</span> = <span class="i">$EdgesVertexIDs</span>[<span class="i">$Index</span> + <span class="n">1</span>]<span class="sc">;</span>
131 118 <span class="i">$Path</span> = <span class="i">new</span> <span class="i">Graph::Path</span><span class="s">(</span><span class="i">$VertexID1</span><span class="cm">,</span> <span class="i">$VertexID2</span><span class="s">)</span><span class="sc">;</span>
132 119 <span class="k">my</span><span class="s">(</span><span class="i">@Paths</span><span class="s">)</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
133 120 <span class="k">push</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">$Path</span><span class="sc">;</span>
134 121 <span class="i">$This</span><span class="i">-&gt;SetEdgeProperty</span><span class="s">(</span><span class="i">$PathsPropertyName</span><span class="cm">,</span> \<span class="i">@Paths</span><span class="cm">,</span> <span class="i">$VertexID1</span><span class="cm">,</span> <span class="i">$VertexID2</span><span class="s">)</span><span class="sc">;</span>
135 122 <span class="s">}</span>
136 123 <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
137 124 <span class="s">}</span>
138 125
139 126 <span class="c"># Collapse paths around a specified vertex by updating paths around the vertex</span>
140 127 <span class="c"># and adding any resulting cyclic paths to vertices attached to specified vertex.</span>
141 128 <span class="c">#</span>
142 129 <span class="c"># Notes:</span>
143 130 <span class="c"># . Path object references are stored as a list attached to Paths property on edges.</span>
144 131 <span class="c"># Usage of list allows multiple paths attached to the egde between a pair of vertices;</span>
145 132 <span class="c"># Graph doesn&#39;t support multiple egdes between a pair of vertices.</span>
146 133 <span class="c">#</span>
147 134 <span class="c"># . Cyclic path object references are stored as list on vertices as CyclicPaths graph property.</span>
148 135 <span class="c"># List allows multiple Loop properties attached to a vertex.</span>
149 136 <span class="c">#</span>
150 137 <span class="c"># . For topologically complex graphs containing large number of cycles, cycles detection algorithm</span>
151 138 <span class="c"># [ Ref 31 ] as implemented implemented in CollapseVertexAndCollectCyclicPathsDetectCycles</span>
152 139 <span class="c"># might not be able to find all the cycles in a reasonable amount of time and is designed to</span>
153 140 <span class="c"># abandon cycles detection after MaxAllowedTime. Consequently, no cycles are detected</span>
154 141 <span class="c"># or assigned.</span>
155 142 <span class="c">#</span>
156 <a name="CollapseVertexAndCollectCyclicPaths-"></a> 143 <span class="k">sub </span><span class="m">CollapseVertexAndCollectCyclicPaths</span> <span class="s">{</span>
157 144 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$VertexID</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
158 145
159 146 <span class="k">if</span> <span class="s">(</span>!<span class="i">$This</span><span class="i">-&gt;HasVertex</span><span class="s">(</span><span class="i">$VertexID</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
160 147 <span class="w">carp</span> <span class="q">&quot;Warning: ${ClassName}-&gt;CollapseVertexAndCollectCyclicPaths: Didn&#39;t collapse vertex $VertexID: Vertex $VertexID doesn&#39;t exist...&quot;</span><span class="sc">;</span>
161 148 <span class="k">return</span> <span class="k">undef</span><span class="sc">;</span>
162 149 <span class="s">}</span>
163 150 <span class="c"># Collect all paths around specified VertexID by going over paths associated with its edges...</span>
164 151 <span class="k">my</span><span class="s">(</span><span class="i">$Index</span><span class="cm">,</span> <span class="i">$EdgePathsRef</span><span class="cm">,</span> <span class="i">$EdgeVertexID1</span><span class="cm">,</span> <span class="i">$EdgeVertexID2</span><span class="cm">,</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@EdgesVertexIDs</span><span class="s">)</span><span class="sc">;</span>
165 152
166 153 <span class="i">@EdgesVertexIDs</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
167 154 <span class="i">@EdgesVertexIDs</span> = <span class="i">$This</span><span class="i">-&gt;GetEdges</span><span class="s">(</span><span class="i">$VertexID</span><span class="s">)</span><span class="sc">;</span>
168 155
169 156 <span class="i">@Paths</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
170 157 <span class="k">for</span> <span class="s">(</span><span class="i">$Index</span> = <span class="n">0</span><span class="sc">;</span> <span class="i">$Index</span> &lt; <span class="i">$#EdgesVertexIDs</span><span class="sc">;</span> <span class="i">$Index</span> += <span class="n">2</span><span class="s">)</span> <span class="s">{</span>
171 158 <span class="s">(</span><span class="i">$EdgeVertexID1</span><span class="cm">,</span> <span class="i">$EdgeVertexID2</span><span class="s">)</span> = <span class="s">(</span><span class="i">$EdgesVertexIDs</span>[<span class="i">$Index</span>]<span class="cm">,</span> <span class="i">$EdgesVertexIDs</span>[<span class="i">$Index</span> + <span class="n">1</span>]<span class="s">)</span><span class="sc">;</span>
172 159 <span class="i">$EdgePathsRef</span> = <span class="i">$This</span><span class="i">-&gt;GetEdgeProperty</span><span class="s">(</span><span class="i">$PathsPropertyName</span><span class="cm">,</span> <span class="i">$EdgeVertexID1</span><span class="cm">,</span> <span class="i">$EdgeVertexID2</span><span class="s">)</span><span class="sc">;</span>
173 160 <span class="k">push</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@</span>{<span class="i">$EdgePathsRef</span>}<span class="sc">;</span>
174 161 <span class="s">}</span>
175 162
176 163 <span class="c"># Go over each pair of paths around the specified vertex, join paths and associate</span>
177 164 <span class="c"># joined path to appropriate edge...</span>
178 165 <span class="k">my</span><span class="s">(</span><span class="i">$Index1</span><span class="cm">,</span> <span class="i">$Index2</span><span class="cm">,</span> <span class="i">$Path1</span><span class="cm">,</span> <span class="i">$Path2</span><span class="cm">,</span> <span class="i">$JoinedPath</span><span class="cm">,</span> <span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="cm">,</span> <span class="i">@CommonVertices</span><span class="s">)</span><span class="sc">;</span>
179 166
180 167 <span class="k">for</span> <span class="s">(</span><span class="i">$Index1</span> = <span class="n">0</span><span class="sc">;</span> <span class="i">$Index1</span> &lt; <span class="i">$#Paths</span><span class="sc">;</span> <span class="i">$Index1</span> +=<span class="n">1</span> <span class="s">)</span> <span class="s">{</span>
181 168 <span class="i">$Path1</span> = <span class="i">$Paths</span>[<span class="i">$Index1</span>]<span class="sc">;</span>
182 169
183 170 <span class="j">PATH2:</span> <span class="k">for</span> <span class="s">(</span><span class="i">$Index2</span> = <span class="i">$Index1</span> + <span class="n">1</span><span class="sc">;</span> <span class="i">$Index2</span> &lt;= <span class="i">$#Paths</span><span class="sc">;</span> <span class="i">$Index2</span> +=<span class="n">1</span> <span class="s">)</span> <span class="s">{</span>
184 171 <span class="i">$Path2</span> = <span class="i">$Paths</span>[<span class="i">$Index2</span>]<span class="sc">;</span>
185 172
186 173 <span class="c"># For JoinedPath to be valid cycle, Path1 and Path2 must have exactly two vertices in common.</span>
187 174 <span class="c"># Otherwise, joined path contains duplicate vertices besides the terminal vertices and</span>
188 175 <span class="c"># indicates a path from a different direction.</span>
189 176 <span class="c">#</span>
190 177 <span class="c"># For paths leading to cycles, it only makes sense to join paths with only one common vertex;</span>
191 178 <span class="c"># otherwise, it wouldn&#39;t lead to a cycle and can be ignored.</span>
192 179 <span class="c">#</span>
193 180 <span class="i">@CommonVertices</span> = <span class="i">$Path1</span><span class="i">-&gt;GetCommonVertices</span><span class="s">(</span><span class="i">$Path2</span><span class="s">)</span><span class="sc">;</span>
194 181 <span class="k">if</span> <span class="s">(</span>!<span class="s">(</span><span class="i">@CommonVertices</span> &lt;= <span class="n">2</span> &amp;&amp; <span class="s">(</span><span class="i">$CommonVertices</span>[<span class="n">0</span>] == <span class="i">$VertexID</span> || <span class="i">$CommonVertices</span>[<span class="n">1</span>] == <span class="i">$VertexID</span><span class="s">)</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
195 182 <span class="k">next</span> <span class="j">PATH2</span><span class="sc">;</span>
196 183 <span class="s">}</span>
197 184
198 185 <span class="i">$JoinedPath</span> = <span class="i">$Path1</span><span class="i">-&gt;JoinAtVertex</span><span class="s">(</span><span class="i">$Path2</span><span class="cm">,</span> <span class="i">$VertexID</span><span class="s">)</span><span class="sc">;</span>
199 186 <span class="s">(</span><span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span> = <span class="i">$JoinedPath</span><span class="i">-&gt;GetTerminalVertices</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
200 187
201 188 <span class="k">if</span> <span class="s">(</span>!<span class="i">$JoinedPath</span><span class="i">-&gt;IsIndependentPath</span><span class="s">(</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
202 189 <span class="k">next</span> <span class="j">PATH2</span><span class="sc">;</span>
203 190 <span class="s">}</span>
204 191
205 192 <span class="c"># Decide whether to give up or keep going...</span>
206 193 <span class="k">if</span> <span class="s">(</span><span class="i">$This</span><span class="i">-&gt;_IsTimeToGiveUpCyclesDetection</span><span class="s">(</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
207 194 <span class="k">warn</span> <span class="q">&quot;Warning: ${ClassName}-&gt;CollapseVertexAndCollectCyclicPaths: Cycles detection algorithm [ Ref 31 ] as implemented in the current release of MayaChemTools didn&#39;t finish with in the maximum allowed time of $This-&gt;{MaxAllowedTime} seconds; Cycles detection has been abandoned...&quot;</span><span class="sc">;</span>
208 195 <span class="k">return</span> <span class="k">undef</span><span class="sc">;</span>
209 196 <span class="s">}</span>
210 197
211 198 <span class="k">if</span> <span class="s">(</span><span class="i">$JoinedPathStartVertexID</span> == <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span> <span class="s">{</span>
212 199 <span class="c"># It&#39;s a cycle. Attach it to the graph as CylicPaths property...</span>
213 200 <span class="k">if</span> <span class="s">(</span><span class="i">$This</span><span class="i">-&gt;HasGraphProperty</span><span class="s">(</span><span class="i">$CyclicPathsPropertyName</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
214 201 <span class="k">my</span><span class="s">(</span><span class="i">$ExistingCyclicPathsRef</span><span class="s">)</span><span class="sc">;</span>
215 202 <span class="i">$ExistingCyclicPathsRef</span> = <span class="i">$This</span><span class="i">-&gt;GetGraphProperty</span><span class="s">(</span><span class="i">$CyclicPathsPropertyName</span><span class="s">)</span><span class="sc">;</span>
216 203 <span class="k">push</span> <span class="i">@</span>{<span class="i">$ExistingCyclicPathsRef</span>}<span class="cm">,</span> <span class="i">$JoinedPath</span><span class="sc">;</span>
217 204 <span class="s">}</span>
218 205 <span class="k">else</span> <span class="s">{</span>
219 206 <span class="k">my</span><span class="s">(</span><span class="i">@NewCyclicPaths</span><span class="s">)</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
220 207 <span class="k">push</span> <span class="i">@NewCyclicPaths</span><span class="cm">,</span> <span class="i">$JoinedPath</span><span class="sc">;</span>
221 208 <span class="i">$This</span><span class="i">-&gt;SetGraphProperty</span><span class="s">(</span><span class="i">$CyclicPathsPropertyName</span><span class="cm">,</span> \<span class="i">@NewCyclicPaths</span><span class="cm">,</span> <span class="i">$JoinedPathStartVertexID</span><span class="s">)</span><span class="sc">;</span>
222 209 <span class="s">}</span>
223 210 <span class="s">}</span>
224 211 <span class="k">else</span> <span class="s">{</span>
225 212 <span class="k">if</span> <span class="s">(</span><span class="i">$This</span><span class="i">-&gt;HasEdge</span><span class="s">(</span><span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
226 213 <span class="c"># Append to the list of exisiting paths property of the edge...</span>
227 214 <span class="k">my</span><span class="s">(</span><span class="i">$ExistingPathsRef</span><span class="s">)</span><span class="sc">;</span>
228 215 <span class="i">$ExistingPathsRef</span> = <span class="i">$This</span><span class="i">-&gt;GetEdgeProperty</span><span class="s">(</span><span class="i">$PathsPropertyName</span><span class="cm">,</span> <span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span><span class="sc">;</span>
229 216 <span class="k">push</span> <span class="i">@</span>{<span class="i">$ExistingPathsRef</span>}<span class="cm">,</span> <span class="i">$JoinedPath</span><span class="sc">;</span>
230 217 <span class="s">}</span>
231 218 <span class="k">else</span> <span class="s">{</span>
232 219 <span class="c"># Create a new edge and associate path property...</span>
233 220 <span class="k">my</span><span class="s">(</span><span class="i">@NewPaths</span><span class="s">)</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
234 221 <span class="k">push</span> <span class="i">@NewPaths</span><span class="cm">,</span> <span class="i">$JoinedPath</span><span class="sc">;</span>
235 222 <span class="i">$This</span><span class="i">-&gt;AddEdge</span><span class="s">(</span><span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span><span class="sc">;</span>
236 223 <span class="i">$This</span><span class="i">-&gt;SetEdgeProperty</span><span class="s">(</span><span class="i">$PathsPropertyName</span><span class="cm">,</span> \<span class="i">@NewPaths</span><span class="cm">,</span> <span class="i">$JoinedPathStartVertexID</span><span class="cm">,</span> <span class="i">$JoinedPathEndVertexID</span><span class="s">)</span><span class="sc">;</span>
237 224 <span class="s">}</span>
238 225 <span class="s">}</span>
239 226 <span class="s">}</span>
240 227 <span class="s">}</span>
241 228 <span class="i">$This</span><span class="i">-&gt;DeleteVertex</span><span class="s">(</span><span class="i">$VertexID</span><span class="s">)</span><span class="sc">;</span>
242 229
243 230 <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
244 231 <span class="s">}</span>
245 232
246 233 <span class="c"># Decide whether to give up cycles detection using collapse vertex methodology...</span>
247 234 <span class="c">#</span>
248 <a name="_IsTimeToGiveUpCyclesDetection-"></a> 235 <span class="k">sub </span><span class="m">_IsTimeToGiveUpCyclesDetection</span> <span class="s">{</span>
249 236 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
250 237
251 238 <span class="k">return</span> <span class="s">(</span><span class="s">(</span><span class="k">time</span> - <span class="i">$This</span>-&gt;{<span class="w">StartTime</span>}<span class="s">)</span> &gt; <span class="i">$This</span>-&gt;{<span class="w">MaxAllowedTime</span>}<span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="n">0</span><span class="sc">;</span>
252 239 <span class="s">}</span>
253 240
254 241 <span class="c"># Delete vertices with degree less than a specifed degree...</span>
255 242 <span class="c">#</span>
256 <a name="DeleteVerticesWithDegreeLessThan-"></a> 243 <span class="k">sub </span><span class="m">DeleteVerticesWithDegreeLessThan</span> <span class="s">{</span>
257 244 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="cm">,</span> <span class="i">$Degree</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
258 245 <span class="k">my</span><span class="s">(</span><span class="i">$VertexID</span><span class="cm">,</span> <span class="i">@VertexIDs</span><span class="s">)</span><span class="sc">;</span>
259 246
260 247 <span class="k">while</span> <span class="s">(</span><span class="i">@VertexIDs</span> = <span class="i">$This</span><span class="i">-&gt;GetVerticesWithDegreeLessThan</span><span class="s">(</span><span class="i">$Degree</span><span class="s">)</span><span class="s">)</span> <span class="s">{</span>
261 248 <span class="k">for</span> <span class="i">$VertexID</span> <span class="s">(</span><span class="i">@VertexIDs</span><span class="s">)</span> <span class="s">{</span>
262 249 <span class="i">$This</span><span class="i">-&gt;DeleteVertex</span><span class="s">(</span><span class="i">$VertexID</span><span class="s">)</span><span class="sc">;</span>
263 250 <span class="s">}</span>
264 251 <span class="s">}</span>
265 252 <span class="k">return</span> <span class="i">$This</span><span class="sc">;</span>
266 253 <span class="s">}</span>
267 254
268 255 <span class="c"># Get paths associated with edges...</span>
269 256 <span class="c">#</span>
270 <a name="GetPaths-"></a> 257 <span class="k">sub </span><span class="m">GetPaths</span> <span class="s">{</span>
271 258 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
272 259 <span class="k">my</span><span class="s">(</span><span class="i">$PathsRef</span><span class="cm">,</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@PathsList</span><span class="s">)</span><span class="sc">;</span>
273 260
274 261 <span class="i">@Paths</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span> <span class="i">@PathsList</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
275 262 <span class="i">@PathsList</span> = <span class="i">$This</span><span class="i">-&gt;GetEdgesProperty</span><span class="s">(</span><span class="i">$PathsPropertyName</span><span class="s">)</span><span class="sc">;</span>
276 263 <span class="k">for</span> <span class="i">$PathsRef</span> <span class="s">(</span><span class="i">@PathsList</span><span class="s">)</span> <span class="s">{</span>
277 264 <span class="k">push</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@</span>{<span class="i">$PathsRef</span>}<span class="sc">;</span>
278 265 <span class="s">}</span>
279 266 <span class="k">return</span> <span class="k">wantarray</span> ? <span class="i">@Paths</span> <span class="co">:</span> <span class="k">scalar</span> <span class="i">@Paths</span><span class="sc">;</span>
280 267 <span class="s">}</span>
281 268
282 269 <span class="c"># Get paths associated with edges which make a cylce...</span>
283 270 <span class="c">#</span>
284 <a name="GetCyclicPaths-"></a> 271 <span class="k">sub </span><span class="m">GetCyclicPaths</span> <span class="s">{</span>
285 272 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
286 273 <span class="k">my</span><span class="s">(</span><span class="i">$PathsRef</span><span class="cm">,</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@PathsList</span><span class="s">)</span><span class="sc">;</span>
287 274
288 275 <span class="i">@Paths</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span> <span class="i">@PathsList</span> = <span class="s">(</span><span class="s">)</span><span class="sc">;</span>
289 276 <span class="i">@PathsList</span> = <span class="i">$This</span><span class="i">-&gt;GetGraphProperty</span><span class="s">(</span><span class="i">$CyclicPathsPropertyName</span><span class="s">)</span><span class="sc">;</span>
290 277 <span class="j">PATHS:</span> <span class="k">for</span> <span class="i">$PathsRef</span> <span class="s">(</span><span class="i">@PathsList</span><span class="s">)</span> <span class="s">{</span>
291 278 <span class="k">if</span> <span class="s">(</span>!<span class="s">(</span><span class="k">defined</span><span class="s">(</span><span class="i">$PathsRef</span><span class="s">)</span> &amp;&amp; <span class="i">@</span>{<span class="i">$PathsRef</span>}<span class="s">)</span><span class="s">)</span> <span class="s">{</span>
292 279 <span class="k">next</span> <span class="j">PATHS</span><span class="sc">;</span>
293 280 <span class="s">}</span>
294 281 <span class="k">push</span> <span class="i">@Paths</span><span class="cm">,</span> <span class="i">@</span>{<span class="i">$PathsRef</span>}<span class="sc">;</span>
295 282 <span class="s">}</span>
296 283 <span class="k">return</span> <span class="k">wantarray</span> ? <span class="i">@Paths</span> <span class="co">:</span> <span class="k">scalar</span> <span class="i">@Paths</span><span class="sc">;</span>
297 284 <span class="s">}</span>
298 285
299 286 <span class="c"># Is it a path graph object?</span>
300 <a name="IsPathGraph-"></a> 287 <span class="k">sub </span><span class="m">IsPathGraph ($)</span> <span class="s">{</span>
301 288 <span class="k">my</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
302 289
303 290 <span class="k">return</span> <span class="i">_IsPathGraph</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span><span class="sc">;</span>
304 291 <span class="s">}</span>
305 292
306 293 <span class="c"># Return a string containg data for PathGraph object...</span>
307 <a name="StringifyPathGraph-"></a> 294 <span class="k">sub </span><span class="m">StringifyPathGraph</span> <span class="s">{</span>
308 295 <span class="k">my</span><span class="s">(</span><span class="i">$This</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
309 296 <span class="k">my</span><span class="s">(</span><span class="i">$PathGraphString</span><span class="s">)</span><span class="sc">;</span>
310 297
311 298 <span class="i">$PathGraphString</span> = <span class="q">&#39;PathGraph:&#39;</span> . <span class="i">$This</span><span class="i">-&gt;StringifyVerticesAndEdges</span><span class="s">(</span><span class="s">)</span> . <span class="q">&#39;; &#39;</span> . <span class="i">$This</span><span class="i">-&gt;StringifyProperties</span><span class="s">(</span><span class="s">)</span><span class="sc">;</span>
312 299
313 300 <span class="k">return</span> <span class="i">$PathGraphString</span><span class="sc">;</span>
314 301 <span class="s">}</span>
315 302
316 303 <span class="c"># Is it a PathGraph object?</span>
317 <a name="_IsPathGraph-"></a> 304 <span class="k">sub </span><span class="m">_IsPathGraph</span> <span class="s">{</span>
318 305 <span class="k">my</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span> = <span class="i">@_</span><span class="sc">;</span>
319 306
320 307 <span class="k">return</span> <span class="s">(</span><span class="i">Scalar::Util::blessed</span><span class="s">(</span><span class="i">$Object</span><span class="s">)</span> &amp;&amp; <span class="i">$Object</span><span class="i">-&gt;isa</span><span class="s">(</span><span class="i">$ClassName</span><span class="s">)</span><span class="s">)</span> ? <span class="n">1</span> <span class="co">:</span> <span class="n">0</span><span class="sc">;</span>
321 308 <span class="s">}</span>
322 309
323 <a name="EOF-"></a></pre>
324 <p>&nbsp;</p>
325 <br />
326 <center>
327 <img src="../../../images/h2o2.png">
328 </center>
329 </body>
330 </html>