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Compatibility with python 3 #6

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35c50bd
clean up and python 3 compatibility
Oct 12, 2018
4a33e7b
fixed name of readme in setup
Oct 12, 2018
f43499b
fixed issues with 35c50bd
Oct 15, 2018
62c256f
Update README.md
SimonDeRidder Mar 14, 2020
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179 changes: 0 additions & 179 deletions Christofides/Christofides.py~
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48 changes: 24 additions & 24 deletions Christofides/christofides.py
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Original file line number Diff line number Diff line change
Expand Up @@ -7,8 +7,6 @@
import networkx as nx
import copy
import itertools
from operator import itemgetter
import graph
import time

def _csr_gen_triples(A):
Expand All @@ -21,7 +19,7 @@ def _csr_gen_triples(A):
data, indices, indptr = A.data, A.indices, A.indptr
for i in range(nrows):
for j in range(indptr[i], indptr[i+1]):
graph.add_edge(i,indices[j], weight = data[j])
graph.add_edge(i,indices[j], weight = data[j])
return graph.edges(data = 'weight')

def _odd_vertices_of_MST(M, number_of_nodes):
Expand Down Expand Up @@ -97,17 +95,16 @@ def create_Multigraph(M, MST, indexes, odd_vertices):
for pair in indexes:
multigraph.add_edge(pair[0],pair[1],weight=M[pair[0]][pair[1]])
return multigraph

def Euler_Tour(multigraph):
""" Uses Fleury's algorithm to find the Euler Tour of the MultiGraph.

"""
tour = []
temp_graph = nx.MultiGraph()
graph_nodes = nx.nodes(multigraph)
current_node = graph_nodes[0]
current_node = [n for n in nx.nodes(multigraph)][0]
tour.append(current_node)
while nx.number_of_edges(multigraph) > 0:
while nx.number_of_edges(multigraph) > 0:
for edge in multigraph.edges(current_node):
temp_graph = copy.deepcopy(multigraph)
temp_graph.remove_edge(edge[0], edge[1], key=None)
Expand All @@ -117,10 +114,12 @@ def Euler_Tour(multigraph):
multigraph.remove_edge(edge[0], edge[1], key=None)
break
else:
edge = [e for e in multigraph.edges(current_node)][-1]
tour.append(edge[1])
current_node = edge[1]
multigraph.remove_edge(edge[0], edge[1], key=None)
multigraph.remove_nodes_from(nx.isolates(multigraph))
isolates = [n for n in nx.isolates(multigraph)]
multigraph.remove_nodes_from(isolates)
return tour

def shortcut_Euler_Tour(tour):
Expand Down Expand Up @@ -156,7 +155,7 @@ def compute(M):
"""
MST = _csr_gen_triples(minimum_spanning_tree(csr_matrix(M)))
odd_vertices = _odd_vertices_of_MST(MST, csr_matrix(M).shape[0])
bipartite_set = [set(i) for i in itertools.combinations(set(odd_vertices), len(odd_vertices)/2)]
bipartite_set = [set(i) for i in itertools.combinations(set(odd_vertices), int(len(odd_vertices)/2))]
bipartite_graphs = bipartite_Graph(M, bipartite_set, odd_vertices)
indexes = min_Munkres(M, bipartite_graphs)
multigraph = create_Multigraph(M, MST, indexes, odd_vertices)
Expand All @@ -165,25 +164,26 @@ def compute(M):
Christofides_Solution = shortcut_Euler_Tour(euler_tour)
Travel_Cost = cost(Christofides_Solution, M)
return {
'Christofides_Solution': Christofides_Solution,
'Travel_Cost': Travel_Cost,
'MST': MST,
'Odd_Vertices': odd_vertices,
'Indexes': indexes,
'Multigraph': multiGraph.edges(data='weight'),
'Christofides_Solution': Christofides_Solution,
'Travel_Cost': Travel_Cost,
'MST': MST,
'Odd_Vertices': odd_vertices,
'Indexes': indexes,
'Multigraph': multiGraph.edges(data='weight'),
'Euler_Tour': euler_tour
}

if __name__ == "__main__":
print 'Testing...'
print('Testing...')
start = time.time()
distance_matrix = graph.distance_matrix
from graph import distance_matrix
Approximation = compute(distance_matrix)
end = time.time()-start
print 'Computation Successful...'
print 'Distance Matrix:\n'
print graph.distance_matrix
print '\n1.5 Approximation of TSP (Christofide\'s algorithm):\n', Approximation['Christofides_Solution']
print 'Travel Cost:', Approximation['Travel_Cost']
print 'Computation Time:', end
print ''
print('Computation Successful...')
print('Distance Matrix:\n')
print(distance_matrix)
print('\n1.5 Approximation of TSP (Christofide\'s algorithm):')
print(Approximation['Christofides_Solution'])
print('Travel Cost:'+str(Approximation['Travel_Cost']))
print('Computation Time:'+str(end))
print('')
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