def read_hypergraph(string):
"""
Read a hypergraph from a string in dot format. Nodes and edges specified in the input will be
added to the current hypergraph.
@type string: string
@param string: Input string in dot format specifying a graph.
@rtype: hypergraph
@return: Hypergraph
"""
hgr = hypergraph()
dotG = pydot.graph_from_dot_data(string)
# Read the hypernode nodes...
# Note 1: We need to assume that all of the nodes are listed since we need to know if they
# are a hyperedge or a normal node
# Note 2: We should read in all of the nodes before putting in the links
for each_node in dotG.get_nodes():
if 'hypernode' == each_node.get('hyper_node_type'):
hgr.add_node(each_node.get_name())
elif 'hyperedge' == each_node.get('hyper_node_type'):
hgr.add_hyperedge(each_node.get_name())
# Now read in the links to connect the hyperedges
for each_link in dotG.get_edges():
if hgr.has_node(each_link.get_source()):
link_hypernode = each_link.get_source()
link_hyperedge = each_link.get_destination()
elif hgr.has_node(each_link.get_destination()):
link_hypernode = each_link.get_destination()
link_hyperedge = each_link.get_source()
hgr.link(link_hypernode, link_hyperedge)
return hgr
def read_hypergraph(string):
"""
Read a graph from a XML document. Nodes and hyperedges specified in the input will be added
to the current graph.
@type string: string
@param string: Input string in XML format specifying a graph.
@rtype: hypergraph
@return: Hypergraph
"""
hgr = hypergraph()
dom = parseString(string)
for each_node in dom.getElementsByTagName("node"):
hgr.add_node(each_node.getAttribute('id'))
for each_node in dom.getElementsByTagName("hyperedge"):
hgr.add_hyperedge(each_node.getAttribute('id'))
dom = parseString(string)
for each_node in dom.getElementsByTagName("node"):
for each_edge in each_node.getElementsByTagName("link"):
hgr.link(str(each_node.getAttribute('id')),
str(each_edge.getAttribute('to')))
return hgr
def read_hypergraph(string):
"""
Read a hypergraph from a string in dot format. Nodes and edges specified in the input will be
added to the current hypergraph.
@type string: string
@param string: Input string in dot format specifying a graph.
@rtype: hypergraph
@return: Hypergraph
"""
hgr = hypergraph()
dotG = pydot.graph_from_dot_data(string)
# Read the hypernode nodes...
# Note 1: We need to assume that all of the nodes are listed since we need to know if they
# are a hyperedge or a normal node
# Note 2: We should read in all of the nodes before putting in the links
for each_node in dotG.get_nodes():
if 'hypernode' == each_node.get('hyper_node_type'):
hgr.add_node(each_node.get_name())
elif 'hyperedge' == each_node.get('hyper_node_type'):
hgr.add_hyperedge(each_node.get_name())
# Now read in the links to connect the hyperedges
for each_link in dotG.get_edges():
if hgr.has_node(each_link.get_source()):
link_hypernode = each_link.get_source()
link_hyperedge = each_link.get_destination()
elif hgr.has_node(each_link.get_destination()):
link_hypernode = each_link.get_destination()
link_hyperedge = each_link.get_source()
hgr.link(link_hypernode, link_hyperedge)
return hgr
def generate_hypergraph(num_nodes, num_edges, r = 0):
"""
Create a random hyper graph.
@type num_nodes: number
@param num_nodes: Number of nodes.
@type num_edges: number
@param num_edges: Number of edges.
@type r: number
@param r: Uniform edges of size r.
"""
# Graph creation
random_graph = hypergraph()
# Nodes
nodes = list(map(str, list(range(num_nodes))))
random_graph.add_nodes(nodes)
# Base edges
edges = list(map(str, list(range(num_nodes, num_nodes+num_edges))))
random_graph.add_hyperedges(edges)
# Connect the edges
if 0 == r:
# Add each edge with 50/50 probability
for e in edges:
for n in nodes:
if choice([True, False]):
random_graph.link(n, e)
else:
# Add only uniform edges
for e in edges:
# First shuffle the nodes
shuffle(nodes)
# Then take the first r nodes
for i in range(r):
random_graph.link(nodes[i], e)
return random_graph
