#!/usr/bin/env python
from nose.tools import *
import networkx as nx
from random import random,choice
class TestUnweightedPath:
def setUp(self):
from networkx import convert_node_labels_to_integers
self.grid=cnlti(nx.grid_2d_graph(4,4),first_label=1,ordering="sorted")
self.cycle=nx.cycle_graph(7)
self.directed_cycle=nx.cycle_graph(7,create_using=nx.DiGraph())
def test_bidirectional_shortest_path(self):
assert_equal(nx.bidirectional_shortest_path(self.cycle,0,3),
[0, 1, 2, 3])
assert_equal(nx.bidirectional_shortest_path(self.cycle,0,4),
[0, 6, 5, 4])
assert_equal(nx.bidirectional_shortest_path(self.grid,1,12),
[1, 2, 3, 4, 8, 12])
assert_equal(nx.bidirectional_shortest_path(self.directed_cycle,0,3),
[0, 1, 2, 3])
def test_shortest_path_length(self):
assert_equal(nx.shortest_path_length(self.cycle,0,3),3)
assert_equal(nx.shortest_path_length(self.grid,1,12),5)
assert_equal(nx.shortest_path_length(self.directed_cycle,0,4),4)
# now with weights
assert_equal(nx.shortest_path_length(self.cycle,0,3,weighted=True),3)
assert_equal(nx.shortest_path_length(self.grid,1,12,weighted=True),5)
assert_equal(nx.shortest_path_length(self.directed_cycle,0,4,weighted=True),4)
def test_single_source_shortest_path(self):
p=nx.single_source_shortest_path(self.cycle,0)
assert_equal(p[3],[0,1,2,3])
def test_single_source_shortest_path_length(self):
assert_equal(nx.single_source_shortest_path_length(self.cycle,0),
{0:0,1:1,2:2,3:3,4:3,5:2,6:1})
def test_all_pairs_shortest_path(self):
p=nx.all_pairs_shortest_path(self.cycle)
assert_equal(p[0][3],[0,1,2,3])
p=nx.all_pairs_shortest_path(self.grid)
assert_equal(p[1][12],[1, 2, 3, 4, 8, 12])
def test_all_pairs_shortest_path_length(self):
l=nx.all_pairs_shortest_path_length(self.cycle)
assert_equal(l[0],{0:0,1:1,2:2,3:3,4:3,5:2,6:1})
l=nx.all_pairs_shortest_path_length(self.grid)
assert_equal(l[1][16],6)
def test_predecessor(self):
G=nx.path_graph(4)
assert_equal(nx.predecessor(G,0),{0: [], 1: [0], 2: [1], 3: [2]})
assert_equal(nx.predecessor(G,0,3),[2])
G=nx.grid_2d_graph(2,2)
assert_equal(sorted(nx.predecessor(G,(0,0)).items()),
[((0, 0), []), ((0, 1), [(0, 0)]),
((1, 0), [(0, 0)]), ((1, 1), [(0, 1), (1, 0)])])
def test_floyd_warshall(self):
XG=nx.DiGraph()
XG.add_weighted_edges_from([('s','u',10) ,('s','x',5) ,
('u','v',1) ,('u','x',2) ,
('v','y',1) ,('x','u',3) ,
('x','v',5) ,('x','y',2) ,
('y','s',7) ,('y','v',6)])
dist, path =nx.floyd_warshall(XG)
assert_equal(dist['s']['v'],9)
assert_equal(path['s']['v'],'u')
assert_equal(dist,
{'y': {'y': 0, 'x': 12, 's': 7, 'u': 15, 'v': 6},
'x': {'y': 2, 'x': 0, 's': 9, 'u': 3, 'v': 4},
's': {'y': 7, 'x': 5, 's': 0, 'u': 8, 'v': 9},
'u': {'y': 2, 'x': 2, 's': 9, 'u': 0, 'v': 1},
'v': {'y': 1, 'x': 13, 's': 8, 'u': 16, 'v': 0}})
GG=XG.to_undirected()
dist, path = nx.floyd_warshall(GG)
assert_equal(dist['s']['v'],8)
assert_equal(path['s']['v'],'y')
G=nx.DiGraph() # no weights
G.add_edges_from([('s','u'), ('s','x'),
('u','v'), ('u','x'),
('v','y'), ('x','u'),
('x','v'), ('x','y'),
('y','s'), ('y','v')])
dist, path = nx.floyd_warshall(G)
assert_equal(dist['s']['v'],2)
assert_equal(path['s']['v'],'x')
dist, path = nx.floyd_warshall(self.cycle)
assert_equal(dist[0][3],3)
assert_equal(path[0][3],2)
assert_equal(dist[0][4],3)
XG3=nx.Graph()
XG3.add_weighted_edges_from([ [0,1,2],[1,2,12],[2,3,1],
[3,4,5],[4,5,1],[5,0,10] ])
dist, path = nx.floyd_warshall(XG3)
assert_equal(dist[0][3],15)
assert_equal(path[0][3],2)
XG4=nx.Graph()
XG4.add_weighted_edges_from([ [0,1,2],[1,2,2],[2,3,1],
[3,4,1],[4,5,1],[5,6,1],
[6,7,1],[7,0,1] ])
dist, path = nx.floyd_warshall(XG4)
assert_equal(dist[0][2],4)
assert_equal(path[0][2],1)
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