def test_children(self):
"""
FUNCTION: children, in graph.py.
"""
"""Use the function to determine the children of each node"""
children = []
for i in range(0, self.n):
children.append(graph.children(self.dag, i))
"""
Assert that the function returns the expected children for each node.
"""
assert children[0] == [1, 2]
assert children[1] == [3]
assert children[2] == [3]
assert children[3] == []
def test_children(self):
"""
FUNCTION: children, in graph.py.
"""
"""Use the function to determine the children of each node"""
children = []
for i in range(0, self.n):
children.append(graph.children(self.dag, i))
"""
Assert that the function returns the expected children for each node.
"""
assert children[0] == [1, 2]
assert children[1] == [3]
assert children[2] == [3]
assert children[3] == []
def dfs_visit(self, u, adj_mat, directed):
"""
Performs a depth first serach visit on a node in a graph.
Parameters
----------
-'u': Int
The index of the node to visit.
-'adj_mat': Numpy ndarray
Adjacency matrix. If adj_mat[i, j] = 1, there exists
a directed edge from node i to node j.
-'directed': Int
Equals 1 if it is a directed graph, 0 otherwise.
"""
self.pre.append(u)
self.color[0, u] = self.gray
self.time_stamp = self.time_stamp + 1
self.d[0, u] = self.time_stamp
if directed == 1:
ns = graph.children(adj_mat, u)
else:
ns = graph.neighbours(adj_mat, u)
ns = np.unique(ns)
ns = np.setdiff1d(np.array(ns), np.array([self.pred[0, u]]))
ns = ns.tolist()
for v in ns:
if self.color[0, v] == self.white:
self.pred[0, v] = u
self.dfs_visit(v, adj_mat, directed)
elif self.color[0, v] == self.gray:
self.cycle = 1
self.color[0, u] = self.black
self.post.append(u)
self.time_stamp = self.time_stamp + 1
self.f[0, u] = self.time_stamp
def dfs_visit(self, u, adj_mat, directed):
"""
Performs a depth first serach visit on a node in a graph.
Parameters
----------
-'u': Int
The index of the node to visit.
-'adj_mat': Numpy ndarray
Adjacency matrix. If adj_mat[i, j] = 1, there exists
a directed edge from node i to node j.
-'directed': Int
Equals 1 if it is a directed graph, 0 otherwise.
"""
self.pre.append(u)
self.color[0, u] = self.gray
self.time_stamp = self.time_stamp + 1
self.d[0, u] = self.time_stamp
if directed == 1:
ns = graph.children(adj_mat, u)
else:
ns = graph.neighbours(adj_mat, u)
ns = np.unique(ns)
ns = np.setdiff1d(np.array(ns), np.array([self.pred[0, u]]))
ns = ns.tolist()
for v in ns:
if self.color[0, v] == self.white:
self.pred[0, v] = u
self.dfs_visit(v, adj_mat, directed)
elif self.color[0, v] == self.gray:
self.cycle = 1
self.color[0, u] = self.black
self.post.append(u)
self.time_stamp = self.time_stamp + 1
self.f[0, u] = self.time_stamp
