hmc.py 文件源码

def sample(self):
        """Define the computation graph for one hmc sampling."""
        accept_rate, new_pos = hmc_sample(
            self.pos, self.stepsize, self.num_steps, self.potential_fn
        )
        new_avg_accept_rate = tf.add(
            self.avg_accept_slowness * self.avg_accept_rate,
            (1.0 - self.avg_accept_slowness) * accept_rate
        )
        new_stepsize = tf.select(new_avg_accept_rate > self.target_accept_rate,
                                 self.stepsize * self.stepsize_inc,
                                 self.stepsize * self.stepsize_dec)
        new_stepsize = tf.clip_by_value(
            new_stepsize, self.stepsize_min, self.stepsize_max
        )
        updates = [self.pos.assign(new_pos),
                   self.stepsize.assign(new_stepsize),
                   self.avg_accept_rate.assign(new_avg_accept_rate)]
        return new_pos, updates


# test =================