def __init__(self):
"""
Initialize a hypergraph.
"""
common.__init__(self)
labeling.__init__(self)
self.node_links = {} # Pairing: Node -> Hyperedge
self.edge_links = {} # Pairing: Hyperedge -> Node
self.graph = graph() # Ordinary graph
def generate(num_nodes, num_edges, directed=False, weight_range=(1, 1)):
"""
Create a random graph.
@type num_nodes: number
@param num_nodes: Number of nodes.
@type num_edges: number
@param num_edges: Number of edges.
@type directed: bool
@param directed: Whether the generated graph should be directed or not.
@type weight_range: tuple
@param weight_range: tuple of two integers as lower and upper limits on randomly generated
weights (uniform distribution).
"""
# Graph creation
if directed:
random_graph = digraph()
else:
random_graph = graph()
# Nodes
nodes = range(num_nodes)
random_graph.add_nodes(nodes)
# Build a list of all possible edges
edges = []
edges_append = edges.append
for x in nodes:
for y in nodes:
if ((directed and x != y) or (x > y)):
edges_append((x, y))
# Randomize the list
shuffle(edges)
# Add edges to the graph
min_wt = min(weight_range)
max_wt = max(weight_range)
for i in range(num_edges):
each = edges[i]
random_graph.add_edge((each[0], each[1]), wt = randint(min_wt, max_wt))
return random_graph