def save(self, file_name, fmt="auto"):
""" overload Graph.save to make output dotfiles pretty.
This is entirely cosmetic. """
u = self
# add some properties to prettify dot output
if fmt is "dot" or fmt is "auto" and file_name.endswith(".dot"):
u = GraphView(self)
# add shape property according to vertex owners
shape = u.new_vertex_property("string")
for v in u.vertices():
if u.vp.owner[v] == 1:
shape[v] = "box"
else:
shape[v] = "diamond"
u.vp.shape = shape
# add label property according to priorities
#u.vertex_properties['label'] = u.vertex_properties['priority']
label = u.new_vertex_property("string")
for v in u.vertices():
prio = u.vertex_properties['priority'][v]
name = u.vertex_index[v]
label[v] = "%d (%d)" % (name, prio)
u.vp.label = label
Graph.save(u, file_name, fmt)
def is_tree(t):
# to undirected
t = GraphView(t, directed=False)
# num nodes = num edges+1
if t.num_vertices() != (t.num_edges() + 1):
return False
# all nodes have degree > 0
vs = list(map(int, t.vertices()))
degs = t.degree_property_map('out').a[vs]
if np.all(degs > 0) == 0:
return False
return True