def read(string):
"""
Read a graph from a string in Dot language and return it. Nodes and edges specified in the
input will be added to the current graph.
@type string: string
@param string: Input string in Dot format specifying a graph.
@rtype: graph
@return: Graph
"""
dotG = pydot.graph_from_dot_data(string)
if (dotG.get_type() == "graph"):
G = graph()
elif (dotG.get_type() == "digraph"):
G = digraph()
elif (dotG.get_type() == "hypergraph"):
return read_hypergraph(string)
else:
raise InvalidGraphType
# Read nodes...
# Note: If the nodes aren't explicitly listed, they need to be
for each_node in dotG.get_nodes():
G.add_node(each_node.get_name())
for each_attr_key, each_attr_val in each_node.get_attributes().items():
G.add_node_attribute(each_node.get_name(), (each_attr_key, each_attr_val))
# Read edges...
for each_edge in dotG.get_edges():
# Check if the nodes have been added
if not G.has_node(each_edge.get_source()):
G.add_node(each_edge.get_source())
if not G.has_node(each_edge.get_destination()):
G.add_node(each_edge.get_destination())
# See if there's a weight
if 'weight' in each_edge.get_attributes().keys():
_wt = each_edge.get_attributes()['weight']
else:
_wt = 1
# See if there is a label
if 'label' in each_edge.get_attributes().keys():
_label = each_edge.get_attributes()['label']
else:
_label = ''
G.add_edge((each_edge.get_source(), each_edge.get_destination()), wt = _wt, label = _label)
for each_attr_key, each_attr_val in each_edge.get_attributes().items():
if not each_attr_key in ['weight', 'label']:
G.add_edge_attribute((each_edge.get_source(), each_edge.get_destination()), \
(each_attr_key, each_attr_val))
return G
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 __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
def read(string):
"""
Read a graph from a XML document and return it. Nodes and edges 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: graph
@return: Graph
"""
dom = parseString(string)
if dom.getElementsByTagName("graph"):
G = graph()
elif dom.getElementsByTagName("digraph"):
G = digraph()
elif dom.getElementsByTagName("hypergraph"):
return read_hypergraph(string)
else:
raise InvalidGraphType
# Read nodes...
for each_node in dom.getElementsByTagName("node"):
G.add_node(each_node.getAttribute('id'))
for each_attr in each_node.getElementsByTagName("attribute"):
G.add_node_attribute(each_node.getAttribute('id'),
(each_attr.getAttribute('attr'),
each_attr.getAttribute('value')))
# Read edges...
for each_edge in dom.getElementsByTagName("edge"):
if (not G.has_edge(
(each_edge.getAttribute('from'), each_edge.getAttribute('to')))):
G.add_edge((each_edge.getAttribute('from'), each_edge.getAttribute('to')), \
wt = float(each_edge.getAttribute('wt')), label = each_edge.getAttribute('label'))
for each_attr in each_edge.getElementsByTagName("attribute"):
attr_tuple = (each_attr.getAttribute('attr'),
each_attr.getAttribute('value'))
if (attr_tuple not in G.edge_attributes((each_edge.getAttribute('from'), \
each_edge.getAttribute('to')))):
G.add_edge_attribute((each_edge.getAttribute('from'), \
each_edge.getAttribute('to')), attr_tuple)
return G
def read(string):
"""
Read a graph from a string in Dot language and return it. Nodes and edges specified in the
input will be added to the current graph.
@type string: string
@param string: Input string in Dot format specifying a graph.
@rtype: graph
@return: Graph
"""
dotG = pydot.graph_from_dot_data(string)
# This is awful, however there seems to be a major incompatibility with pygraph
# and current pydot. Pydot now returns a list of graphs from a dot string. Rather
# than possibly rewrite a big chunk of this lib, we'll just use the first graph.
# Since rez only makes single graphs anyway, this should suffice.
#
# https://github.com/nerdvegas/rez/issues/884
#
# <hack>
if isinstance(dotG, list):
dotG = dotG[0]
# </endhack>
if (dotG.get_type() == "graph"):
G = graph()
elif (dotG.get_type() == "digraph"):
G = digraph()
elif (dotG.get_type() == "hypergraph"):
return read_hypergraph(string)
else:
raise InvalidGraphType
# Read nodes...
# Note: If the nodes aren't explicitly listed, they need to be
for each_node in dotG.get_nodes():
G.add_node(each_node.get_name())
for each_attr_key, each_attr_val in each_node.get_attributes().items():
G.add_node_attribute(each_node.get_name(),
(each_attr_key, each_attr_val))
# Read edges...
for each_edge in dotG.get_edges():
# Check if the nodes have been added
if not G.has_node(each_edge.get_source()):
G.add_node(each_edge.get_source())
if not G.has_node(each_edge.get_destination()):
G.add_node(each_edge.get_destination())
# See if there's a weight
if 'weight' in each_edge.get_attributes().keys():
_wt = each_edge.get_attributes()['weight']
else:
_wt = 1
# See if there is a label
if 'label' in each_edge.get_attributes().keys():
_label = each_edge.get_attributes()['label']
else:
_label = ''
G.add_edge((each_edge.get_source(), each_edge.get_destination()),
wt=_wt,
label=_label)
for each_attr_key, each_attr_val in each_edge.get_attributes().items():
if not each_attr_key in ['weight', 'label']:
G.add_edge_attribute((each_edge.get_source(), each_edge.get_destination()), \
(each_attr_key, each_attr_val))
return G
def read(string):
"""
Read a graph from a string in Dot language and return it. Nodes and edges specified in the
input will be added to the current graph.
@type string: string
@param string: Input string in Dot format specifying a graph.
@rtype: graph
@return: Graph
"""
dotG = pydot.graph_from_dot_data(string)
if (dotG.get_type() == "graph"):
G = graph()
elif (dotG.get_type() == "digraph"):
G = digraph()
elif (dotG.get_type() == "hypergraph"):
return read_hypergraph(string)
else:
raise InvalidGraphType
# Read nodes...
# Note: If the nodes aren't explicitly listed, they need to be
for each_node in dotG.get_nodes():
G.add_node(each_node.get_name())
for each_attr_key, each_attr_val in each_node.get_attributes().items():
G.add_node_attribute(each_node.get_name(),
(each_attr_key, each_attr_val))
# Read edges...
for each_edge in dotG.get_edges():
# Check if the nodes have been added
if not G.has_node(each_edge.get_source()):
G.add_node(each_edge.get_source())
if not G.has_node(each_edge.get_destination()):
G.add_node(each_edge.get_destination())
# See if there's a weight
if 'weight' in each_edge.get_attributes().keys():
_wt = each_edge.get_attributes()['weight']
else:
_wt = 1
# See if there is a label
if 'label' in each_edge.get_attributes().keys():
_label = each_edge.get_attributes()['label']
else:
_label = ''
G.add_edge((each_edge.get_source(), each_edge.get_destination()),
wt=_wt,
label=_label)
for each_attr_key, each_attr_val in each_edge.get_attributes().items():
if not each_attr_key in ['weight', 'label']:
G.add_edge_attribute((each_edge.get_source(), each_edge.get_destination()), \
(each_attr_key, each_attr_val))
return G
