epsilon_decay.py 文件源码

def tf_explore(self, episode=0, timestep=0, num_actions=1):

        def true_fn():
            # Know if first is not true second must be true from outer cond check.
            return tf.cond(
                pred=(timestep < self.start_timestep),
                true_fn=(lambda: self.initial_epsilon),
                false_fn=(lambda: self.final_epsilon)
            )

        def false_fn():
            half_life_ratio = (tf.cast(x=timestep, dtype=util.tf_dtype('float')) - self.start_timestep) / self.half_life
            epsilon = self.final_epsilon + (2 ** (-half_life_ratio)) * (self.initial_epsilon - self.final_epsilon)
            return epsilon

        pred = tf.logical_or(x=(timestep < self.start_timestep), y=(timestep > self.start_timestep + self.timesteps))
        return tf.cond(pred=pred, true_fn=true_fn, false_fn=false_fn)