def kullbackLeiblerDistance(fac1, fac2, base=2):
"""
Calculates the Kullback-Leibler Distance between fac1 and fac2. The factors
should represent probability distributions with the same variables, like
P(X) and Q(X), or P(X, Y) and Q(X, Y)
:param fac1: First factor in operation
:param fac2: Second factor in operation
:param base: Base of logarithms in the operations, defaults to 2
:returns: The Kullback-Leibler Distance
"""
kld = lambda f1, f2: f1 * log(f1 / f2) / log(base)
return sum(Factor.factorOp(fac1, fac2, kld).values)
def kullbackLeiblerDistance(fac1, fac2, base=2):
"""
Calculates the Kullback-Leibler Distance between fac1 and fac2. The factors
should represent probability distributions with the same variables, like
P(X) and Q(X), or P(X, Y) and Q(X, Y)
:param fac1: First factor in operation
:param fac2: Second factor in operation
:param base: Base of logarithms in the operations, defaults to 2
:returns: The Kullback-Leibler Distance
"""
kld = lambda f1, f2: f1 * log(f1 / f2) / log(base)
return sum(Factor.factorOp(fac1, fac2, kld).values)
