Thanks again @ptrblck
Yes, I am using Numpy.
here an example of what I am doing to create a tensors from  list and numpy.
drr = Variable(drr, requires_grad=theta.requires_grad)
landmark_batch = Variable(torch.tensor(landmark_batch, dtype=torch.float32, device=theta.device), requires_grad=theta.requires_grad)
Would this detach drr and landmark_batch? if yes, how can I write a custom autograd.Function to create tensors from numpy and list?