'Kullback-Leibler divergence between this and another distribution
int f(x) (log f(x) - log g(x)) dx
where f is the pdf of self, and g is the pdf of other
uses double integration with scipy.integrate.dblquad
limits currently hardcoded'

def kl(self, other):

    fun = (lambda x: (self.logpdf(x) - other.logpdf(x)))
    return self.expect(fun)
