def _two(self, g, s1, cut1, val1):
''' solves 2-decomposition '''
# get root.
root = g.graph['root']
# greedy graph constraction.
logging.info("two contracting")
psz = len(g.nodes())
while 1 == 1:
test = False
for e in g.edges():
# graph active sets.
sa = g.node[e[0]]['set']
sb = g.node[e[1]]['set']
# check if we cant merge.
if len(sa) + len(sb) > self._cutoff: continue
# dont touch root.
if e[0] == root or e[1] == root: continue
# make new node info.
n = "%s_%s" % (str(e[0]), str(e[1]))
s = g.node[e[0]]['set'].union(g.node[e[1]]['set'])
# insert into graph.
g.add_node(n, {'set':s, 'graph':None})
# rehook edges.
for q in g.neighbors(e[0]):
if q == e[1]: continue
cut = g[e[0]][q]['cut']
g.remove_edge(e[0], q)
g.add_edge(n, q, {'cut':cut})
for q in g.neighbors(e[1]):
if q == e[0]: continue
cut = g[e[1]][q]['cut']
g.remove_edge(e[1], q)
g.add_edge(n, q, {'cut':cut})
# do contraction.
g.remove_edge(e[0], e[1])
g.remove_node(e[0])
g.remove_node(e[1])
# break and reset.
test = True
break
# check if there was no mod.
if test == False:
break
logging.info("two contracted: %i to %i" % (psz, len(g.nodes())))
# solve bottom up.
logging.info("solving two (bottom): %d" % len(s1))
for p, q, kids in self._dfs_gen(g, root, order=False):
# grab active set.
s2 = g.node[p]['set']
# if its the root just solve.
if q == -1:
# just solve.
self._load(s2)
if cut1 in s2:
self._force(cut1, val1)
sol, val = self._solve()
self._clear()
# save to root.
g.node[p]['sol'] = sol
g.node[p]['val'] = val
else:
# get cuts.
cuts = g[p][q]['cut']
# solve 4 combinations of orientations.
for x, y in itertools.product([0,1], repeat=2):
# solve.
self._load(s2)
if cut1 in s2:
self._force(cut1, val1)
self._force(cuts[0], x)
self._force(cuts[1], y)
sol, val = self._solve()
self._clear()
# save info.
g.node[p]['sol_%i_%i' % (x,y)] = sol
g.node[p]['val_%i_%i' % (x,y)] = val
# prepare a partial solution.
nlist = build_nlist(self._nodes, s1)
blist = build_blist(self._bundles, s1)
tlist = build_tlist(self._bundles, s1)
partial = PartialSolution(nlist.size, blist.size)
val = 0.0
# apply solution top down.
logging.info("applying two (top): %d" % len(s1))
for p, q, kids in self._dfs_gen(g, root, order=True):
# grab active set.
s2 = g.node[p]['set']
# just apply root.
if q == -1:
partial.merge(g.node[p]['sol'])
val += g.node[p]['val']
continue
# determine what the parent did.
cuts = g[p][q]['cut']
oa = partial.get_orien(cuts[0])
ob = partial.get_orien(cuts[1])
# apply that solution.
partial.merge(g.node[p]['sol_%i_%i' % (oa, ob)])
val += g.node[p]['val_%i_%i' % (oa, ob)]
# return the solution.
return partial, val
def _one(self, g, s0):
''' solves one component '''
# greedy graph constraction.
logging.info("one contracting")
psz = len(g.nodes())
while 1 == 1:
test = False
for e in g.edges():
# graph active sets.
sa = g.node[e[0]]['set']
sb = g.node[e[1]]['set']
# check if we cant merge.
if len(sa) + len(sb) > self._cutoff: continue
# make new node info.
n = "%s_%s" % (str(e[0]), str(e[1]))
s = g.node[e[0]]['set'].union(g.node[e[1]]['set'])
# insert into graph.
g.add_node(n, {'set':s, 'graph':None})
# rehook edges.
for q in g.neighbors(e[0]):
if q == e[1]: continue
cut = g[e[0]][q]['cut']
g.remove_edge(e[0], q)
g.add_edge(n, q, {'cut':cut})
for q in g.neighbors(e[1]):
if q == e[0]: continue
cut = g[e[1]][q]['cut']
g.remove_edge(e[1], q)
g.add_edge(n, q, {'cut':cut})
# do contraction.
g.remove_edge(e[0], e[1])
g.remove_node(e[0])
g.remove_node(e[1])
# break and reset.
test = True
break
# check if there was no mod.
if test == False:
break
logging.info("one contracted: %i to %i" % (psz, len(g.nodes())))
# choose root.
root = g.nodes()[0]
# solve bottom up.
logging.info("solving one (bottom): %d" % len(s0))
for p, q, kids in self._dfs_gen(g, root, order=False):
# grab active set.
s1 = g.node[p]['set']
g1 = g.node[p]['graph']
large = len(s1) > self._cutoff
# if its the root just solve.
if q == -1:
# just solve (hope its not a 2-component).
if large == False:
# solve normal.
self._load(s1)
sol, val = self._solve()
self._clear()
else:
# solve 2 decomp.
print "NOT WRITTEN"
sys.exit()
# save to root.
g.node[p]['sol'] = sol
g.node[p]['val'] = val
else:
# get cut.
cut = g[p][q]['cut']
# solve 2 combinations of orientations.
logging.info("solving one: %d" % len(s1))
for x in [0, 1]:
# switch on solve.
if large == False:
# solve normal.
self._load(s1)
self._force(cut, x)
sol, val = self._solve()
self._clear()
else:
# solve decompose.
sol, val = self._two(g1, s1, cut, x)
# save info.
g.node[p]['sol_%i' % x] = sol
g.node[p]['val_%i' % x] = val
# prepare a partial solution.
nlist = build_nlist(self._nodes, s0)
blist = build_blist(self._bundles, s0)
tlist = build_tlist(self._bundles, s0)
partial = PartialSolution(nlist.size, blist.size)
val = 0.0
# apply solution top down.
logging.info("applying one (top): %d" % len(s0))
for p, q, kids in self._dfs_gen(g, root, order=True):
# grab active set.
s1 = g.node[p]['set']
# just apply root.
if q == -1:
partial.merge(g.node[p]['sol'])
val += g.node[p]['val']
continue
# determine what the parent did.
cut = g[p][q]['cut']
o = partial.get_orien(cut)
# apply that solution.
partial.merge(g.node[p]['sol_%i' % o])
val += g.node[p]['val_%i' % o]
# return solution.
return partial, val
