general.py 文件源码

def logp_crp(N, Nk, alpha):
    """Returns the log normalized P(N,K|alpha), where N is the number of
    customers and K is the number of tables.
    http://gershmanlab.webfactional.com/pubs/GershmanBlei12.pdf#page=4 (eq 8)
    """
    return len(Nk)*log(alpha) + np.sum(lgamma(c) for c in Nk) \
        + lgamma(alpha) - lgamma(N+alpha)