length.py 文件源码

def _get_eos_prob(self):
        """Get loglikelihood according cur_p, cur_r, and n_consumed """
        eos_point_prob = self._get_eos_point_prob(max(
                                              1, 
                                              self.n_consumed - self.offset))
        if self.use_point_probs:
            return eos_point_prob - self.max_eos_prob
        if not self.prev_eos_probs:
            self.prev_eos_probs.append(eos_point_prob)
            return eos_point_prob
        # bypass utils.log_sum because we always want to use logsumexp here 
        prev_sum = logsumexp(np.asarray([p for p in self.prev_eos_probs])) 
        self.prev_eos_probs.append(eos_point_prob)
        # Desired prob is eos_point_prob / (1-last_eos_probs_sum)
        return eos_point_prob - np.log(1.0-np.exp(prev_sum))