"""
Test cases for functions in graph_utils.py
-- kandasamy@cs.cmu.edu
"""
# pylint: disable=import-error
# pylint: disable=no-member
# pylint: disable=invalid-name
# pylint: disable=relative-import
# pylint: disable=no-name-in-module
import numpy as np
import graph_utils
from time import clock
from utils.base_test_class import BaseTestClass, execute_tests
from scipy.sparse import dok_matrix
ERR_TOL_FRAC = 1e-5
class GraphUtilsTestCase(BaseTestClass):
""" Unit test class for ancillary utilities. """
def setUp(self):
""" Sets up attributes. """
self.num_vertices_values = [4, 10, 50, 100]
def test_apsp_algos(self):
""" Tests the all pairs shortest pair problems. """
# Todo: write code to compute computation time.
self.report('Testing All Pairs Shortest Paths for n=%s.'%(
str(self.num_vertices_values)))
for num_vert_val in self.num_vertices_values:
# Floyd warshall
A = graph_utils.construct_random_adjacency_matrix(num_vert_val, avg_edge_frac=0.4,
directed=True)
num_edges = A.sum()
fw_start_time = clock()
fw_dist = graph_utils.apsp_floyd_warshall(A) # call floyd_warshall
fw_end_time = clock()
fw_time_taken = fw_end_time - fw_start_time
# Dijkstra's
dj_start_time = clock()
dj_dist = graph_utils.apsp_dijkstra(A) # call dijkstra's
dj_end_time = clock()
dj_time_taken = dj_end_time - dj_start_time
# Report times taken
self.report('Time taken for n=%d, m=%d: FW: %0.4f, Dijkstra\'s: %0.4f.'%(
A.shape[0], num_edges, fw_time_taken, dj_time_taken))
# Test if both are equal
fw_infties = fw_dist == np.inf
dj_infties = dj_dist == np.inf
assert np.all(fw_infties == dj_infties)
# Zer out the infinities and compare the norms
fw_dist[fw_infties] = 0
dj_dist[dj_infties] = 0
error_tol = ERR_TOL_FRAC * np.linalg.norm(dj_dist + fw_dist)
assert np.linalg.norm(fw_dist - dj_dist) < error_tol
def test_kahn_topoligical_sort(self):
""" Tests topological sorting. """
self.report('Testing topological sort.')
A = dok_matrix((6, 6))
A[0, 2] = 1
A[1, 2] = 1
A[1, 3] = 1
A[2, 3] = 1
A[2, 4] = 1
A[4, 3] = 1
A[5, 0] = 1
A[5, 1] = 1
sorted_order, has_cycles = graph_utils.kahn_topological_sort(A, 5)
assert has_cycles == False
assert sorted_order == [5, 0, 1, 2, 4, 3] or sorted_order == [5, 1, 0, 2, 4, 3]
# Now create a graph with cycles
A[3, 0] = 1
sorted_order, has_cycles = graph_utils.kahn_topological_sort(A, 5)
assert has_cycles == True
if __name__ == '__main__':
execute_tests()
