UserWarning: Implicit dimension choice for log_softmax has been deprecated

Question

I´m using Mac OS el capitán and I am trying to follow the quick start tutorial for OpenNMT pytorch version. In the training step I get the following warning message:

OpenNMT-py/onmt/modules/GlobalAttention.py:177: UserWarning: Implicit dimension choice for softmax has been deprecated. Change the call to include dim=X as an argument. 

align_vectors = self.sm(align.view(batch*targetL, sourceL))
/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/torch/nn/modules/container.py:67: UserWarning: Implicit dimension choice for log_softmax has been deprecated. Change the call to include dim=X as an argument.
  input = module(input)

Step 1: Preprocess data (works as expected)

python preprocess.py -train_src data/src-train.txt -train_tgt data/tgt-train.txt -valid_src data/src-val.txt -valid_tgt data/tgt-val.txt -save_data data/demo

Step 2: Train model (produces the warning message)

python train.py -data data/demo -save_model demo-model

Has anyone come across this warning or have any pointers to solve it?

Answer 1

It is almost always you will need the last dimension when you compute the cross-entropy so your line may look like:

torch.nn.functional.log_softmax(x, -1)