cl3.py

def hash_collapsed_likelihood(tprior, gmean, gvar, tcount, s1):
    "Assumes a single hyperparameter"
    p0 = np.log(gamma_pdf(tprior, gmean, gvar))
    s0 = len(tcount)
    p0 += s0*(gammaln(tprior*s1)-sum(gammaln(tprior) for i in xrange(s1)))
    for d in xrange(s0):
        for i,t in tcount[d].items():
            p0 += gammaln(t + tprior)
        p0 += (s1-len(tcount[d]))*gammaln(tprior)
        p0 -= gammaln(sum(tcount[d]) + s1*tprior)
    return p0