albanD:

This line looks suspicious:         target_a = Variable(target_a, requires_grad = True)
Note that Variable are not a thing anymore so you can remove it.


Hello thank you very much for your time.
" This line looks suspicious:         target_a = Variable(target_a, requires_grad = True)
Note that Variable are not a thing anymore so you can remove it."
I deleted it , but leads to same results.
" I think you break the graph earlier. In particular, reward_a is computed with estimation_control_numpy which contains a .data breaking the graph (note that you should not use .data anymore. You can replace it with .detach() here)."
I think you indicate something very useful.
where can i find .data ? i do not see it explicitly. so how to reslve this problem?  sorry , but i cannot imagine using .detach. can you suggest how?
ideally, i want the  “estimation_control_numpy” to lead the target_a formation, and backprop within the graph.
thanks.