Compute Jensen-Shannon divergence between p1 and p2.
    It assumes that p1 and p2 are already normalized that each of them sums to 1.

def jsd(p1, p2):
    """Compute Jensen-Shannon divergence between p1 and p2.
    It assumes that p1 and p2 are already normalized that each of them sums to 1.
    """
    m = (p1 + p2) / 2
    return (kld(p1, m) + kld(p2, m)) / 2