| Line | Hits | Source |
|---|---|---|
| 1 | /* | |
| 2 | * Copyright (c) 2003, the JUNG Project and the Regents of the University | |
| 3 | * of California | |
| 4 | * All rights reserved. | |
| 5 | * | |
| 6 | * This software is open-source under the BSD license; see either | |
| 7 | * "license.txt" or | |
| 8 | * http://jung.sourceforge.net/license.txt for a description. | |
| 9 | */ | |
| 10 | /* | |
| 11 | * Created on Apr 21, 2004 | |
| 12 | */ | |
| 13 | package edu.uci.ics.jung.algorithms.transformation; | |
| 14 | ||
| 15 | import java.util.HashMap; | |
| 16 | import java.util.HashSet; | |
| 17 | import java.util.Iterator; | |
| 18 | import java.util.Map; | |
| 19 | import java.util.Set; | |
| 20 | ||
| 21 | import org.apache.commons.collections.BidiMap; | |
| 22 | import org.apache.commons.collections.Predicate; | |
| 23 | ||
| 24 | import edu.uci.ics.jung.graph.ArchetypeVertex; | |
| 25 | import edu.uci.ics.jung.graph.Edge; | |
| 26 | import edu.uci.ics.jung.graph.Element; | |
| 27 | import edu.uci.ics.jung.graph.Graph; | |
| 28 | import edu.uci.ics.jung.graph.Hypergraph; | |
| 29 | import edu.uci.ics.jung.graph.KPartiteGraph; | |
| 30 | import edu.uci.ics.jung.graph.Vertex; | |
| 31 | import edu.uci.ics.jung.graph.decorators.NumberEdgeValue; | |
| 32 | import edu.uci.ics.jung.graph.impl.DirectedSparseEdge; | |
| 33 | import edu.uci.ics.jung.graph.impl.DirectedSparseGraph; | |
| 34 | import edu.uci.ics.jung.graph.impl.UndirectedSparseEdge; | |
| 35 | import edu.uci.ics.jung.graph.impl.UndirectedSparseGraph; | |
| 36 | import edu.uci.ics.jung.utils.GraphUtils; | |
| 37 | import edu.uci.ics.jung.utils.PredicateUtils; | |
| 38 | import edu.uci.ics.jung.utils.TypedVertexGenerator; | |
| 39 | import edu.uci.ics.jung.utils.UserData; | |
| 40 | import edu.uci.ics.jung.utils.VertexGenerator; | |
| 41 | import edu.uci.ics.jung.utils.UserDataContainer.CopyAction; | |
| 42 | ||
| 43 | /** | |
| 44 | * A class for creating a "folded" graph based on a k-partite graph or a | |
| 45 | * hypergraph. | |
| 46 | * | |
| 47 | * <p>A "folded" graph is derived from a k-partite graph by identifying | |
| 48 | * a partition of vertices which will become the vertices of the new graph, copying | |
| 49 | * these vertices into the new graph, and then connecting those vertices whose | |
| 50 | * original analogues were connected indirectly through elements | |
| 51 | * of other partitions. (See <code>fold(KPartiteGraph, Predicate, NumberEdgeValue)</code> | |
| 52 | * for more details.)</p> | |
| 53 | * | |
| 54 | * <p>A "folded" graph is derived from a hypergraph by creating vertices based on | |
| 55 | * either the vertices or the hyperedges of the original graph, and connecting | |
| 56 | * vertices in the new graph if their corresponding vertices/hyperedges share a | |
| 57 | * connection with a common hyperedge/vertex. (See <code>fold(Hypergraph, | |
| 58 | * boolean, NumberEdgeValue)</code> for more details.)</p> | |
| 59 | * | |
| 60 | * @author Danyel Fisher | |
| 61 | * @author Joshua O'Madadhain | |
| 62 | */ | |
| 63 | public class FoldingTransformer | |
| 64 | { | |
| 65 | /** | |
| 66 | * Used in <code>fold()</code> as a user data key to the data attached to | |
| 67 | * the edges in the folded graph. | |
| 68 | */ | |
| 69 | public static final String FOLDED_DATA = "edu.uci.ics.jung.graph.KPartiteFolder:Folded Data"; | |
| 70 | ||
| 71 | protected boolean parallel; | |
| 72 | 2 | protected CopyAction copy_action = UserData.REMOVE; |
| 73 | ||
| 74 | /** | |
| 75 | * Specifies whether the graph being folded is undirected or not. | |
| 76 | * Set by <code>checkGraphConstraints</code>. | |
| 77 | */ | |
| 78 | private boolean undirected; | |
| 79 | ||
| 80 | /** | |
| 81 | * Creates an instance of this Folder. See the discussion of fold for notes | |
| 82 | * on the "parallel" argument. | |
| 83 | * | |
| 84 | */ | |
| 85 | 2 | public FoldingTransformer(boolean parallel) { |
| 86 | 2 | this.parallel = parallel; |
| 87 | 2 | } |
| 88 | ||
| 89 | /** | |
| 90 | * Specifies whether the folded graphs create parallel edges or a decorated | |
| 91 | * single edge. | |
| 92 | * @param parallel | |
| 93 | */ | |
| 94 | public void setParallel(boolean parallel) { | |
| 95 | 0 | this.parallel = parallel; |
| 96 | 0 | } |
| 97 | ||
| 98 | /** | |
| 99 | * Specifies the copy action used to attach data to edges. | |
| 100 | * @param copy_action | |
| 101 | */ | |
| 102 | public void setCopyAction(CopyAction copy_action) | |
| 103 | { | |
| 104 | 0 | this.copy_action = copy_action; |
| 105 | 0 | } |
| 106 | ||
| 107 | /** | |
| 108 | * Equivalent to <code>fold(g, p, null)</code>. | |
| 109 | */ | |
| 110 | public Graph fold(KPartiteGraph g, Predicate p) | |
| 111 | { | |
| 112 | 2 | return fold(g, p, null); |
| 113 | } | |
| 114 | ||
| 115 | /** | |
| 116 | * <p> | |
| 117 | * Converts <code>g</code> into a unipartite graph whose vertex set is the | |
| 118 | * vertices whose partition is specified by <code>p</code>. For vertices | |
| 119 | * <code>a</code> and <code>b</code> in this partition, the resultant | |
| 120 | * graph will include the edge <code>(a,b)</code> if the original graph | |
| 121 | * contains edges <code>(a,c)</code> and <code>(c,b)</code> for at least | |
| 122 | * one vertex <code>c</code>. | |
| 123 | * </p> | |
| 124 | * | |
| 125 | * <p> | |
| 126 | * If <code>parallel</code> is true, then each such connecting vertex | |
| 127 | * <code>c</code> will be represented by a single edge in the resultant | |
| 128 | * graph, and the resultant graph may therefore contain parallel edges. | |
| 129 | * Otherwise, each edge <code>(a,b)</code> in the resultant graph will be | |
| 130 | * annotated with the set of vertices <code>c</code> that connected | |
| 131 | * <code>a</code> to <code>b</code> in the original graph, and the | |
| 132 | * graph's edge requirements will be set to refuse parallel edges. | |
| 133 | * </p> | |
| 134 | * | |
| 135 | * <p>In either case, if the original graph contains both a directed edge from | |
| 136 | * <code>a</code> to <code>b</code>, and a directed edge from <code>b</code> | |
| 137 | * <code>a</code>, then a self-loop will be created from <code>a</code> | |
| 138 | * to itself in the folded graph. Undirected edges do not result in | |
| 139 | * self-loops. | |
| 140 | * </p> | |
| 141 | * | |
| 142 | * <p> | |
| 143 | * If <code>g</code> is neither strictly directed nor strictly undirected, | |
| 144 | * this method throws <code>IllegalArgumentException</code>. Parallel edges | |
| 145 | * in the original graph have no effect on the resultant graph: only one edge | |
| 146 | * <code>(a,c)</code> and one edge <code>(c,b)</code> are necessary to | |
| 147 | * induce a connection between <code>a</code> and <code>b</code> in the folded | |
| 148 | * graph, and any additional such edges are ignored.</p> | |
| 149 | * | |
| 150 | * <p>If <code>nev</code> is null, | |
| 151 | * adds the connecting element as a decoration on the corresponding edge in the new | |
| 152 | * graph; otherwise, sets the weight of each edge to the number of parallel | |
| 153 | * paths between the corresponding vertices in the original graph that are | |
| 154 | * encountered in the folding process.</p> | |
| 155 | * | |
| 156 | * @param g the graph to fold | |
| 157 | * @param p the predicate which specifies the partition to fold into | |
| 158 | * @return the folded graph | |
| 159 | * @throws IllegalArgumentException | |
| 160 | */ | |
| 161 | public Graph fold(KPartiteGraph g, Predicate p, NumberEdgeValue nev) | |
| 162 | { | |
| 163 | 2 | checkGraphConstraints(g); |
| 164 | ||
| 165 | 2 | Graph newGraph = createGraph(); |
| 166 | ||
| 167 | // get vertices for the specified partition, copy into new graph | |
| 168 | 2 | Set vertices = PredicateUtils.getVertices(g, p); |
| 169 | 2 | for (Iterator iter = vertices.iterator(); iter.hasNext();) { |
| 170 | 6 | ArchetypeVertex v = (ArchetypeVertex) iter.next(); |
| 171 | 6 | v.copy(newGraph); |
| 172 | } | |
| 173 | ||
| 174 | 2 | for (Iterator iter = vertices.iterator(); iter.hasNext();) { |
| 175 | 6 | Vertex v = (Vertex) iter.next(); |
| 176 | 6 | Vertex v_new = (Vertex) v.getEqualVertex(newGraph); |
| 177 | 6 | Set succs = v.getSuccessors(); |
| 178 | ||
| 179 | 6 | for (Iterator s_iter = succs.iterator(); s_iter.hasNext();) { |
| 180 | 10 | Vertex s = (Vertex) s_iter.next(); |
| 181 | 10 | Set s_succs = s.getSuccessors(); |
| 182 | ||
| 183 | 10 | for (Iterator t_iter = s_succs.iterator(); t_iter.hasNext();) { |
| 184 | 13 | Vertex t = (Vertex) t_iter.next(); |
| 185 | ||
| 186 | // if t is in the partition of interest | |
| 187 | // and has not been covered (undirected graphs only) | |
| 188 | 13 | if (!vertices.contains(t)) continue; |
| 189 | ||
| 190 | 13 | Vertex t_new = (Vertex) t.getEqualVertex(newGraph); |
| 191 | 13 | addEdge(newGraph, v_new, s, t_new, nev); |
| 192 | ||
| 193 | } | |
| 194 | } | |
| 195 | } | |
| 196 | 2 | return newGraph; |
| 197 | } | |
| 198 | ||
| 199 | // /** | |
| 200 | // * Equivalent to <code>fold(h, use_vertices, null)</code>. | |
| 201 | // */ | |
| 202 | // public Graph fold(Hypergraph h, boolean use_vertices) | |
| 203 | // { | |
| 204 | // return fold(h, use_vertices, null); | |
| 205 | // } | |
| 206 | // | |
| 207 | // public Graph fold(Hypergraph h, boolean use_vertices, NumberEdgeValue nev) | |
| 208 | // { | |
| 209 | // return fold(h, null, use_vertices, nev, new BidirectionalHashMap()); | |
| 210 | // } | |
| 211 | ||
| 212 | /** | |
| 213 | * Creates a <code>Graph</code> which is a "folded" version of <code>h</code>. | |
| 214 | * | |
| 215 | * <p>If <code>use_vertices</code> is true, the vertices of the new graph | |
| 216 | * correspond to the vertices of <code>h</code>, and <code>a</code> | |
| 217 | * is connected to <code>b</code> in the new graph if the corresponding vertices | |
| 218 | * in <code>h</code> are connected by a hyperedge. Thus, each hyperedge with | |
| 219 | * <i>k</i> vertices in <code>h</code> would induce a <i>k</i>-clique in the new graph.</p> | |
| 220 | * | |
| 221 | * <p>If <code>use_vertices</code> is false, then the vertices of the new | |
| 222 | * graph correspond to the hyperedges of <code>h</code>, and <code>a</code> | |
| 223 | * is connected to <code>b</code> in the new graph if the corresponding hyperedges | |
| 224 | * in <code>h</code> share a vertex. Thus, each vertex connected to <i>k</i> | |
| 225 | * hyperedges in <code>h</code> would induce a <i>k</i>-clique in the new graph.</p> | |
| 226 | * | |
| 227 | * <p>If <code>nev</code> is null, | |
| 228 | * adds the connecting element as a decoration on the corresponding edge in the new | |
| 229 | * graph; otherwise, sets the weight of each edge to the number of parallel | |
| 230 | * paths between the corresponding vertices in the original graph that are | |
| 231 | * encountered in the folding process.</p> | |
| 232 | */ | |
| 233 | public Graph fold(Hypergraph h, Graph target, boolean use_vertices, NumberEdgeValue nev, BidiMap map) | |
| 234 | { | |
| 235 | 0 | undirected = true; |
| 236 | ||
| 237 | 0 | if (target == null) |
| 238 | 0 | target = createGraph(); |
| 239 | ||
| 240 | 0 | VertexGenerator vg = GraphUtils.getVertexGenerator(target); |
| 241 | 0 | if (vg == null) |
| 242 | 0 | vg = new TypedVertexGenerator(target); |
| 243 | ||
| 244 | 0 | Map m = new HashMap(); |
| 245 | Set vertices; | |
| 246 | Set edges; | |
| 247 | ||
| 248 | // vertices and hyperedges are duals of one another; we can treat | |
| 249 | // them equivalently for this purpose | |
| 250 | 0 | if (use_vertices) |
| 251 | { | |
| 252 | 0 | vertices = h.getVertices(); |
| 253 | 0 | edges = h.getEdges(); |
| 254 | } | |
| 255 | else | |
| 256 | { | |
| 257 | 0 | vertices = h.getEdges(); |
| 258 | 0 | edges = h.getVertices(); |
| 259 | } | |
| 260 | ||
| 261 | // create vertices: | |
| 262 | // for each "vertex", create a new vertex and import user data | |
| 263 | 0 | for (Iterator iter = vertices.iterator(); iter.hasNext(); ) |
| 264 | { | |
| 265 | 0 | Element av = (Element)iter.next(); |
| 266 | 0 | Vertex v = vg.create(); |
| 267 | 0 | v.importUserData(av); |
| 268 | 0 | target.addVertex(v); |
| 269 | 0 | m.put(av, v); |
| 270 | 0 | map.put(v, av); |
| 271 | } | |
| 272 | ||
| 273 | // create edges: | |
| 274 | // for each "hyperedge", create an edge between each incident vertex pair | |
| 275 | 0 | for (Iterator iter = edges.iterator(); iter.hasNext(); ) |
| 276 | { | |
| 277 | 0 | Element he = (Element)iter.next(); |
| 278 | 0 | Set elts = he.getIncidentElements(); |
| 279 | 0 | Vertex[] v_array = new Vertex[elts.size()]; |
| 280 | 0 | int i = 0; |
| 281 | 0 | for (Iterator e_iter = elts.iterator(); e_iter.hasNext(); ) |
| 282 | 0 | v_array[i++] = (Vertex)(m.get(e_iter.next())); |
| 283 | 0 | for (i = 0; i < v_array.length; i++) |
| 284 | 0 | for (int j = i + 1; j < v_array.length; j++) |
| 285 | 0 | addEdge(target, v_array[i], he, v_array[j], nev); |
| 286 | } | |
| 287 | ||
| 288 | 0 | return target; |
| 289 | } | |
| 290 | ||
| 291 | ||
| 292 | /** | |
| 293 | * Creates a new edge from <code>firstEnd</code> to <code>secondEnd</code> | |
| 294 | * in <code>newGraph</code>. Note that | |
| 295 | * <code>firstEnd</code> and <code>secondEnd</code> are both parts of | |
| 296 | * <code>newGraph</code>, while | |
| 297 | * <code>intermediate</code> is part of the original graph. If <code>parallel</code> is set, | |
| 298 | * adds a new edge from <code>firstEnd</code> to <code>secondEnd</code>. | |
| 299 | * If <code>parallel</code> is not set, then (as appropriate) adds an edge | |
| 300 | * or creates one from <code>firstEnd</code> to <code>secondEnd</code>. | |
| 301 | */ | |
| 302 | protected void addEdge(Graph newGraph, Vertex firstEnd, | |
| 303 | Element intermediate, Vertex secondEnd, NumberEdgeValue nev) | |
| 304 | { | |
| 305 | 13 | if( undirected && firstEnd == secondEnd ) return; |
| 306 | 8 | if (parallel) { |
| 307 | Edge v_t; | |
| 308 | 4 | if (undirected) |
| 309 | 0 | v_t = new UndirectedSparseEdge(firstEnd, secondEnd); |
| 310 | else | |
| 311 | 4 | v_t = new DirectedSparseEdge(firstEnd, secondEnd); |
| 312 | 4 | if (nev != null) |
| 313 | 0 | nev.setNumber(v_t, new Integer(1)); |
| 314 | else | |
| 315 | 4 | v_t.addUserDatum(FOLDED_DATA, intermediate, copy_action); |
| 316 | 4 | newGraph.addEdge(v_t); |
| 317 | } else { | |
| 318 | 4 | Edge v_t = firstEnd.findEdge(secondEnd); |
| 319 | 4 | if (v_t == null) { |
| 320 | 1 | if (undirected) |
| 321 | 1 | v_t = new UndirectedSparseEdge(firstEnd, secondEnd); |
| 322 | else | |
| 323 | 0 | v_t = new DirectedSparseEdge(firstEnd, secondEnd); |
| 324 | 1 | if (nev != null) |
| 325 | 0 | nev.setNumber(v_t, new Integer(0)); |
| 326 | else | |
| 327 | 1 | v_t.addUserDatum(FOLDED_DATA, new HashSet(), copy_action); |
| 328 | 1 | newGraph.addEdge(v_t); |
| 329 | } | |
| 330 | 4 | if (nev != null) |
| 331 | 0 | nev.setNumber(v_t, new Integer(nev.getNumber(v_t).intValue() + 1)); |
| 332 | else | |
| 333 | { | |
| 334 | 4 | Set folded_vertices = (Set) v_t.getUserDatum(FOLDED_DATA); |
| 335 | 4 | folded_vertices.add(intermediate); |
| 336 | } | |
| 337 | } | |
| 338 | 8 | } |
| 339 | ||
| 340 | /** | |
| 341 | * Returns a base graph to use. | |
| 342 | */ | |
| 343 | protected Graph createGraph() | |
| 344 | { | |
| 345 | Graph newGraph; | |
| 346 | 2 | if (undirected) |
| 347 | 1 | newGraph = new UndirectedSparseGraph(); |
| 348 | else | |
| 349 | 1 | newGraph = new DirectedSparseGraph(); |
| 350 | ||
| 351 | 2 | if (parallel) |
| 352 | 1 | newGraph.getEdgeConstraints().remove(Graph.NOT_PARALLEL_EDGE); |
| 353 | ||
| 354 | 2 | return newGraph; |
| 355 | } | |
| 356 | ||
| 357 | /** | |
| 358 | * Checks for, and rejects, mixed-mode graphs, and sets the <code>undirected</code> | |
| 359 | * class variable state. | |
| 360 | */ | |
| 361 | protected void checkGraphConstraints(KPartiteGraph g) { | |
| 362 | 2 | undirected = PredicateUtils.enforcesUndirected(g); |
| 363 | 2 | if (!undirected && !PredicateUtils.enforcesDirected(g)) |
| 364 | 0 | throw new IllegalArgumentException( |
| 365 | "Graph must be strictly " | |
| 366 | + "directed or strictly undirected (no mixed graphs allowed)"); | |
| 367 | 2 | } |
| 368 | ||
| 369 | } |
|
this report was generated by version 1.0.5 of jcoverage. |
copyright © 2003, jcoverage ltd. all rights reserved. |