def init(bn, tht, valcs, clqs, vclqixs):
pots = [pot.Potential(clq, valcs) for clq in clqs]
for v, (clqix, thtv) in enumerate(izip(vclqixs, tht)):
clq = clqs[clqix]
pots[clqix] *= vpot(v, bn, thtv, valcs)
return pots
def sepot(self, jt, clqs, valcs):
spots = {}
for (x,y) in jt.edges():
svars = list(set(clqs[x]) & set(clqs[y]))
svars.sort()
spots[(x,y)] = pot.Potential(svars, valcs)
return spots
def infer(insts):
lhs = [pot.Potential([v], valcs) for v in xrange(len(vclqs))]
for v, i in insts:
if isinstance(i, int):
newi = [0.0] * valcs(v)
newi[i] = 1.0
i = newi
insert_evidence(lhs, v, map(float, i), pots[vclqs[v]])
spots = sepot(jt, clqs, valcs)
globprop(jt, pots, spots)
dstrs = []
for v, clqix in enumerate(vclqs):
cpot = pots[clqix]
dstr = (cpot >> pot.Potential([v], valcs, 0.0)).normalize().p
dstrs.append(dstr)
return dstrs
def insert_evidence(self, vars, vals):
if isinstance(dstr, int):
val = dstr
dstr = [0.0]*self.valcs(v)
dstr[val] = 1.0
old_lhv = self.lhs[v]
new_lhv = pot.Potential(old_lhv.vars, old_lhv.valcs)
new_lhv.p = dstr[:]
self.lhs[v] = new_lhv
vpot = self.pots[self.vclqs[v]]
vpot *= new_lhv / old_lhv
def vpot(v, bn, thtv, valcs):
ps = utils.ops(v, bn)
fam = ps + [v]
fam.sort()
vp = pot.Potential(fam, valcs)
vix = fam.index(v)
for fcfg in utils.cfgs(valcs(fam)):
cfg = list(fcfg)
vl = cfg.pop(vix)
cfg = tuple(cfg)
vp[fcfg] = thtv(tuple(cfg))[vl]
return vp
def __init__(self, valcs, jt, clqs, pots, vclqs):
# CONSTANTS
self.valcs = valcs
self.jt = jt
self.clqs = clqs
self.vclqs = vclqs
self.nof_vars = len(vclqs)
# AND WORK VARIABLES
self.pots_ = pots
self.spots_ = self.sepot(jt, clqs, valcs)
self.lhs_ = [pot.Potential([v], valcs) for v in xrange(self.nof_vars)]
self.reset()
def infer1(self,v, needs_propagation=True):
if needs_propagation:
self.globprop(self.jt, self.pots, self.spots)
cpot = self.pots[self.vclqs[v]]
return (cpot >> pot.Potential([v], self.valcs, 0.0)).normalize().p
def insert_evidence(lhs, v, p, vpot):
old_lhv = lhs[v]
new_lhv = pot.Potential(old_lhv.vars, old_lhv.valcs)
new_lhv.p = p[:]
vpot *= new_lhv / old_lhv
lhs[v] = new_lhv