RobertaForClassification throws an error because of dimension mismatch

[ErikVogelLUH]

System Info

transformers version 4.41.2, Windows 10

Who can help?

@ArthurZucker

Information

• [ ] The official example scripts
• [ ] My own modified scripts

Tasks

• [ ] An officially supported task in the examples folder (such as GLUE/SQuAD, ...)
• [ ] My own task or dataset (give details below)

Reproduction

I wanted to train a Roberta model for classification. However, during the computation of the loss for multi-label classification, the dimensions are mismatched. I found the problem in transformers/models/roberta/modeling_roberta.py:1229:

loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))

The labels are flattened but the logits are formed to have dimensions (batch_size, num_labels). Slightly changing the line fixes the problem

loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1, self.num_labels))

Expected behavior

Compute the loss without the dimension mismatch

[LysandreJik]

Hey @ErikVogelLUH! It's a bit hard to help you without knowing the code that failed. We know this model works well with our scripts (such as this one: https://github.com/huggingface/transformers/tree/main/examples/pytorch/text-classification)

Did you start from one of our scripts or from something else?