Assertion error of nn.BCELoss

1

Hi,
When I use nn.BCELoss() for the criterion, I have the assertion error:

anaconda3/lib/python3.6/site-packages/torch/nn/_functions/thnn/loss.py in forward(self, input, target)
     20 
     21     def forward(self, input, target):
---> 22         assert input.nelement() == target.nelement()
     23         self._resize_weight(target)
     24         result = super(BCELoss, self).forward(input, target)

But when I change the loss into nn.CrossEntropy(), it is OK to run.
What is the problem here?

2

BCELoss expects input and target to have the same number of elements. CrossEntropyLoss requires targets to be nBatch, input to be nBatch x nClasses. Read the documentation.