def test_djikstra(self):
dag = Dag()
a, b, c, d = dag.add_vertices(4)
dag.add_edge(a, b, 3)
dag.add_edge(a, c, 4)
dag.add_edge(b, d, 4)
dag.add_edge(c, d, 1)
self.assertEqual(dag.djikstra(a, d), (5, [a, c, d]))
def test_difficult_dag(self):
dag = Dag()
v = dag.add_vertices(10)
dag.add_edge(v[0], v[1], 1)
dag.add_edge(v[0], v[2], 2)
dag.add_edge(v[1], v[2], 5)
dag.add_edge(v[1], v[3], 1)
dag.add_edge(v[2], v[4], 2)
dag.add_edge(v[3], v[2], 3)
dag.add_edge(v[3], v[4], 1)
dag.add_edge(v[4], v[5], 2)
self.assertEqual(dag.djikstra(v[0], v[5]), (5, [v[0], v[1], v[3], v[4], v[5]]))
dag.add_edge(v[2], v[5], 1)
self.assertEqual(dag.djikstra(v[0], v[5]), (3, [v[0], v[2], v[5]]))
import random
from dag import Dag
#Create a random graph
n_nodes = 10
n_edges = 20
randseed = 18
graph_is_dag = True
dag1 = Dag()
random.seed(randseed)
for i in range(n_nodes):
dag1.add_node(i)
for i in range(n_edges):
node1 = random.randint(0,n_nodes-1)
node2 = random.randint(0,n_nodes-1)
dag1.add_edge(node1, node2)
if graph_is_dag:
while not dag1.validate():
node1 = random.randint(0,n_nodes-1)
node2 = random.randint(0,n_nodes-1)
dag1.add_edge(node1, node2)
# remove an edge between two nodes that are known to be connected
print dag1.graph
print dag1.graph
from dag import Dag
from random import randrange
import numpy as np
#Construct a random DAG
n = 10 # no. of nodes
p = 0.2 # probability of adding an edge
m = 50 # max. no. of edge-adding attempts
dag1 = Dag()
for i in range(n):
dag1.add_node(i)
for i in range(m):
addedge = np.random.choice(a=[True, False], p=[p,1-p])
if addedge:
j = randrange(0,n-2)
k = j
while k <= j:
k = randrange(0,n-1)
dag1.add_edge(j,k)
else:
continue
#if there are any independent nodes (other than the first), add a dependency
while dag1.ind_nodes() != [0]:
i = dag1.ind_nodes()[-1]
if i != 1: dag1.add_edge(randrange(0,i-1),i)
elif i == 1: dag1.add_edge(0,i)
print dag1.graph
