I am trying on time-series control simulation by means of a LSTM controller, which uses response sensor signal to gernerate driving signal. The target is to minimize the response.
“Trying to backward through the graph a second time (or directly access saved tensors after they have already been freed). Saved intermediate values of the graph are freed when you call .backward() or autograd.grad(). Specify retain_graph=True if you need to backward through the graph a second time or if you need to access saved tensors after calling backward.”
However, this inter-state variable record the final state of last step, which is critical for the simulation.
“RuntimeError: one of the variables needed for gradient computation has been modified by an inplace operation: [torch.cuda.FloatTensor [32, 6]], which is output 0 of AsStridedBackward0, is at version 2; expected version 1 instead. Hint: the backtrace further above shows the operation that failed to compute its gradient. The variable in question was changed in there or anywhere later. Good luck!”
How could I keep the inter-state variable through loss.backward(),
I learn a lot from the post below. However, I still cannot solve it.