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#!/usr/bin/env python |
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# $Id: boostgraph.py,v 1.1 2008/02/08 09:05:02 joko Exp $ |
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# (c) 2008 Andreas Motl <andreas.motl@ilo.de> |
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# This program is free software: you can redistribute it and/or modify |
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# it under the terms of the GNU Affero General Public License as published by |
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# the Free Software Foundation, either version 3 of the License, or |
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# (at your option) any later version. |
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# |
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# This program is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU Affero General Public License for more details. |
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# |
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# You should have received a copy of the GNU Affero General Public License |
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# along with this program. If not, see <http://www.gnu.org/licenses/>. |
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# Uses BGL-Python (depth_first_search) |
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# |
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# BGL-Python Homepage: http://osl.iu.edu/~dgregor/bgl-python/ |
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# |
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# Documentation (Boost): |
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# - http://www.boost.org/libs/graph/doc/graph_theory_review.html |
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# - http://www.boost.org/libs/graph/doc/depth_first_search.html |
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# - http://www.boost.org/boost/graph/depth_first_search.hpp |
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# - http://www.boost.org/libs/graph/doc/DFSVisitor.html |
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# - http://www.boost.org/libs/graph/example/dfs-example.cpp |
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# |
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# Documentation (BGL-Python): |
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# - http://osl.iu.edu/~dgregor/bgl-python/reference/boost.graph.html |
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# |
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# Subversion-Repository: https://svn.osl.iu.edu/svn/projects_viz/bgl-python/ |
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import sys, os |
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sys.path.append('bgl_python') |
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os.environ['PATH'] += ';' + './bgl_python' |
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import boost.graph as bgl |
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# from http://www.boost.org/libs/graph/doc/DFSVisitor.html |
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class tree_edges_dfs_visitor(bgl.dfs_visitor): |
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def __init__(self, name_map): |
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#bgl.dfs_visitor.__init__(self) |
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self.name_map = name_map |
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|
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# for recognizing path switches |
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self.state = True |
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|
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# for tracking paths |
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self.paths = [] |
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self.current_path = [] |
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|
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def tree_edge(self, e, g): |
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(u, v) = (g.source(e), g.target(e)) |
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print "Tree edge ", |
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print self.name_map[u], |
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print " -> ", |
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print self.name_map[v] |
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self.state = True |
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self.current_path.append(e) |
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#return False |
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|
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def start_vertex(self, v, g): |
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#self._seperator() |
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pass |
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#print 'sssss' |
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def initialize_vertex(self, v, g): |
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#print '>>>' |
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self._seperator('initialize_vertex') |
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def finish_vertex(self, v, g): |
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#print '<<<' |
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if self.current_path: |
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self.paths.append(self.current_path) |
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self.current_path = [] |
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self._seperator('finish_vertex') |
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def _seperator(self, label = 'unknown'): |
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if self.state: |
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print '-' * 21, label |
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self.state = False |
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def build_fixed_graph(): |
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graph = bgl.Graph() |
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index = {} |
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# doesn't this work? see http://www.nabble.com/-Graph--Getting-PageRank-to-work-in-BGL-Python-td14207115.html |
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#graph.add_vertex_property_map(name='my_name', type='float') |
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# 'write_graphviz' requires property 'node_id' on vertices |
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# see http://lists.boost.org/boost-users/2006/06/19877.php |
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vmap = graph.vertex_property_map('string') |
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graph.vertex_properties['node_id'] = vmap |
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v1 = graph.add_vertex() |
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vmap[v1] = '1' |
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index['1'] = v1 |
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v2 = graph.add_vertex() |
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vmap[v2] = '2' |
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index['2'] = v2 |
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v3 = graph.add_vertex() |
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vmap[v3] = '3' |
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index['3'] = v3 |
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v4 = graph.add_vertex() |
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vmap[v4] = '4' |
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index['4'] = v4 |
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e1 = graph.add_edge(v1, v2) |
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e2 = graph.add_edge(v1, v3) |
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e3 = graph.add_edge(v3, v4) |
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""" |
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for vertex in graph.vertices: |
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#print vertex.id, vertex |
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print vmap[vertex], vertex |
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#print vertex.__getattribute__('id') |
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#print vertex['id'] |
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#print vertex.get('id') |
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#print |
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""" |
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graph.write_graphviz('friends.dot') |
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return (graph, index) |
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def find_path_solutions(source, target, graph, paths): |
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print |
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print "=" * 42 |
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print "find_path_solutions" |
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print "=" * 42 |
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#print visitor.paths |
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#(u, v) = (g.source(e), g.target(e)) |
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for path in paths: |
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startVertex = graph.source(path[0]) |
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endVertex = graph.target(path[-1]) |
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if source == startVertex and target == endVertex: |
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print "found" |
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def main(): |
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# Load a graph from the GraphViz file 'mst.dot' |
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#graph = bgl.Graph.read_graphviz('mst.dot') |
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(graph, index) = build_fixed_graph() |
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# Compute all paths rooted from each vertex |
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#mst_edges = bgl.kruskal_minimum_spanning_tree(graph, weight) |
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#bgl.depth_first_search(graph, root_vertex = None, visitor = None, color_map = None) |
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for root in graph.vertices: |
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print |
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print '=' * 42 |
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print 'Paths originating from node %s' % graph.vertex_properties['node_id'][root] |
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visitor = tree_edges_dfs_visitor(graph.vertex_properties['node_id']) |
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bgl.depth_first_search(graph, root_vertex = root, visitor = visitor, color_map = None) |
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find_path_solutions(index['4'], index['2'], graph, visitor.paths) |
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# STOP HERE |
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sys.exit(0) |
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# Compute the weight of the minimum spanning tree |
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#print 'MST weight =',sum([weight[e] for e in mst_edges]) |
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# Put the weights into the label. Make MST edges solid while all other |
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# edges remain dashed. |
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label = graph.edge_property_map('string') |
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style = graph.edge_property_map('string') |
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for e in graph.edges: |
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label[e] = str(weight[e]) |
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if e in mst_edges: |
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style[e] = 'solid' |
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else: |
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style[e] = 'dashed' |
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# Associate the label and style property maps with the graph for output |
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graph.edge_properties['label'] = label |
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graph.edge_properties['style'] = style |
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# Write out the graph in GraphViz DOT format |
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graph.write_graphviz('friends_path_2to3.dot') |
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if __name__ == '__main__': |
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main() |