RuntimeError when using a += b but not when doing a= a + b #2425
Description
With PyTorch I'm having a problem doing an operation with two Variables:
sub_patch : [torch.FloatTensor of size 9x9x32]
pred_patch : [torch.FloatTensor of size 5x5x32]
sub_patch is a Variable made by torch.zeros
pred_patch is a Variable of which I index each of the 25 nodes with a nested for-loop, and that I multiply with its corresponding unique filter (sub_filt_patch) of size [5,5,32]. The result is added to its respective place in sub_patch.
This is a piece of my code:
for i in range(filter_sz):
for j in range(filter_sz):
# index correct filter from filter tensor
sub_filt_col = (patch_col + j) * filter_sz
sub_filt_row = (patch_row + i) * filter_sz
sub_filt_patch = sub_filt[sub_filt_row:(sub_filt_row + filter_sz), sub_filt_col:(sub_filt_col+filter_sz), :]
# multiply filter and pred_patch and sum onto sub patch
sub_patch[i:(i + filter_sz), j:(j + filter_sz), :] += (sub_filt_patch * pred_patch[i,j]).sum(dim=3)
The error I get from the bottom line of the piece of code here is
RuntimeError: in-place operations can be only used on variables that don't share storage with any other variables, but detected that there are 2 objects sharing it
This Error is not raised when using:
sub_patch[i:(i + filter_sz), j:(j + filter_sz), :] = sub_patch[i:(i + filter_sz), j:(j + filter_sz), :] + (sub_filt_patch * pred_patch[i,j]).sum(dim=3)
instead of
sub_patch[i:(i + filter_sz), j:(j + filter_sz), :] += (sub_filt_patch * pred_patch[i,j]).sum(dim=3)
Could this be a bug?