univariate.py 文件源码

def _log_prob(self, given):
        # TODO: not right when given=0 or 1
        alpha, beta = self.alpha, self.beta
        log_given = tf.log(given)
        log_1_minus_given = tf.log(1 - given)
        lgamma_alpha, lgamma_beta = tf.lgamma(alpha), tf.lgamma(beta)
        lgamma_alpha_plus_beta = tf.lgamma(alpha + beta)

        if self._check_numerics:
            log_given = tf.check_numerics(log_given, "log(given)")
            log_1_minus_given = tf.check_numerics(
                log_1_minus_given, "log(1 - given)")
            lgamma_alpha = tf.check_numerics(lgamma_alpha, "lgamma(alpha)")
            lgamma_beta = tf.check_numerics(lgamma_beta, "lgamma(beta)")
            lgamma_alpha_plus_beta = tf.check_numerics(
                lgamma_alpha_plus_beta, "lgamma(alpha + beta)")

        return (alpha - 1) * log_given + (beta - 1) * log_1_minus_given - (
            lgamma_alpha + lgamma_beta - lgamma_alpha_plus_beta)