I know return is total discounted reward of an episode,so it is easy to plot return vs. episode.But in many papers,they provide figures of average return vs step,like this:
Based on my knowledge,return is discounted cumulative rewards of an episode,it can't be calculated until the end of episodes,so I feel puzzled about how to calculate average return at each training step.
Does return of each training step mean discounted cumulative rewards collected from current training step to the end of current episode?If an agent is trained with N episodes,and each episode has T step,then I can calculate return of the (i-1)Tth step to the iTth step when the ith episode ends and plot return vs. step if all N episodes finish,is it right?