67 lines
2.1 KiB
Python
67 lines
2.1 KiB
Python
# Copyright 2010-2011 Google
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Test linear sum assignment on a 4x4 matrix.
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Example taken from:
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http://www.ee.oulu.fi/~mpa/matreng/eem1_2-1.htm with kCost[0][1]
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modified so the optimum solution is unique.
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"""
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from google.apputils import app
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from graph import pywrapgraph
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def RunAssignmentOn4x4Matrix(forward_graph):
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"""Test linear sum assignment on a 4x4 matrix.
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Arguments:
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forward_graph: if true uses a ForwardStarGraph or a StarGraph to model
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the assignment problem.
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"""
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num_sources = 4
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num_targets = 4
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cost = [[90, 76, 75, 80],
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[35, 85, 55, 65],
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[125, 95, 90, 105],
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[45, 110, 95, 115]]
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expected_cost = cost[0][3] + cost[1][2] + cost[2][1] + cost[3][0]
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if forward_graph:
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graph = pywrapgraph.ForwardStarGraph(num_sources + num_targets,
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num_sources * num_targets)
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assignment = pywrapgraph.ForwardEbertLinearSumAssignment(graph, num_sources)
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else:
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graph = pywrapgraph.StarGraph(num_sources + num_targets,
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num_sources * num_targets)
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assignment = pywrapgraph.EbertLinearSumAssignment(graph, num_sources)
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for source in range (0, num_sources):
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for target in range(0, num_targets):
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arc = graph.AddArc(source, num_sources + target)
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assignment.SetArcCost(arc, cost[source][target])
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assignment.ComputeAssignment()
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total_cost = assignment.GetCost()
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print 'total cost', total_cost, '/', expected_cost
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def main(unused_argv):
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RunAssignmentOn4x4Matrix(True)
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RunAssignmentOn4x4Matrix(False)
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if __name__ == '__main__':
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app.run()
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