def __init__(self, D):
# refine partition of states by reversed neighborhoods
N = D.reverse()
P = PartitionRefinement(D.states())
P.refine([s for s in D.states() if D.isfinal(s)])
unrefined = Sequence(P, key=id)
while unrefined:
part = arbitrary_item(unrefined)
unrefined.remove(part)
for symbol in D.alphabet:
neighbors = set()
for state in part:
neighbors |= N.transition(state, symbol)
for new, old in P.refine(neighbors):
if old in unrefined or len(new) < len(old):
unrefined.append(new)
else:
unrefined.append(old)
# convert partition to DFA
P.freeze()
self.partition = P
self.initial = P[D.initial]
self.alphabet = D.alphabet
self.DFA = D
def LexBFS(G):
"""Find lexicographic breadth-first-search traversal order of a graph.
G should be represented in such a way that "for v in G" loops through
the vertices, and "G[v]" produces a sequence of the neighbors of v; for
instance, G may be a dictionary mapping each vertex to its neighbor set.
Running time is O(n+m) and additional space usage over G is O(n).
"""
P = PartitionRefinement(G)
S = Sequence(P, key=id)
while S:
set = S[0]
v = arbitrary_item(set)
yield v
P.remove(v)
if not set:
S.remove(set)
for new,old in P.refine(G[v]):
S.insertBefore(old,new)
def __init__(self,D):
# refine partition of states by reversed neighborhoods
N = D.reverse()
P = PartitionRefinement(D.states())
P.refine([s for s in D.states() if D.isfinal(s)])
unrefined = Sequence(P,key=id)
while unrefined:
part = arbitrary_item(unrefined)
unrefined.remove(part)
for symbol in D.alphabet:
neighbors = Set()
for state in part:
neighbors |= N.transition(state,symbol)
for new,old in P.refine(neighbors):
if old in unrefined or len(new) < len(old):
unrefined.append(new)
else:
unrefined.append(old)
# convert partition to DFA
P.freeze()
self.partition = P
self.initial = P[D.initial]
self.alphabet = D.alphabet
self.DFA = D
def minimize(dfa):
''' Under construction :)
Based on ...
'''
# refine partition of states by reversed neighborhoods
partition = PartitionRefinement(dfa.g.nodes_iter())
partition.refine(dfa.final)
unrefined = dict([(id(p), p) for p in partition])
while unrefined:
part = unrefined.pop(unrefined.iterkeys().next())
for symbol in dfa.alphabet:
neighbors = set([
v for v, _, d in dfa.g.in_edges_iter(part, data=True)
if symbol in d['input']
])
for new, old in partition.refine(neighbors):
if id(old) in unrefined or len(new) < len(old):
unrefined[id(new)] = new
else:
unrefined[id(old)] = old
print dfa.g.number_of_nodes()
print len(list(partition))
# convert partition to DFA
nx.condensation
