language_helpers.py 文件源码

def js_with(self, p):
        log_p = np.array([p.log_likelihood(ngram) for ngram in p.unique_ngrams()])
        log_q = np.array([self.log_likelihood(ngram) for ngram in p.unique_ngrams()])
        log_m = np.logaddexp(log_p - np.log(2), log_q - np.log(2))
        kl_p_m = np.sum(np.exp(log_p) * (log_p - log_m))

        log_p = np.array([p.log_likelihood(ngram) for ngram in self.unique_ngrams()])
        log_q = np.array([self.log_likelihood(ngram) for ngram in self.unique_ngrams()])
        log_m = np.logaddexp(log_p - np.log(2), log_q - np.log(2))
        kl_q_m = np.sum(np.exp(log_q) * (log_q - log_m))

        return 0.5*(kl_p_m + kl_q_m) / np.log(2)