* Add classwise weight in losses:CE,BCE,softBCE
* Update unit test
* rm some extra code
* rm some extra code
* fix broadcast
* fix broadcast
* update unit tests
* use new_tensor
* fix lint
* Add API inference in the docs and fix readthedocs config.
* Replace some relative link in docs.
* Format docstring for reStructuredText syntax.
* Fix vit paper link
* Fix docstring of `show_results` function in `BaseClassifier`.
* add convert_to_one_hot
* add test_label_smooth_loss
* add my label_smooth_loss
* fix CELoss bug
* test new label smooth loss
* LabelSmoothLoss downward compatibility
* add some comments
* remove the old version of LabelSmoothLoss
* add some comments
* add some comments
* add some comments
* add label smooth to config
* Add mixup option
* Modify the structure of mixup and add configs
* Clean configs
* Add test for mixup and SoftCrossEntropyLoss
* Add simple test for ImageClassifier
* Fix bug in test_losses.py
* Add assertion in CrossEntropyLoss
* resolve conflicts
add heads and config for multilabel tasks
* minor change
* remove evaluating mAP in head
* add baseline config
* add configs
* reserve only one config
* minor change
* fix minor bug
* minor change
* minor change
* add unittests and fix docstrings
* add bce loss for multilabel task
* minor change
* apply class wise sum
* fix docstring
* do not apply sum over classes and fix docstring
* fix docstring
* fix weight shape
* fix weight shape
* fix docstring
* fix linting issue
Co-authored-by: Y. Xiong <xiongyuxy@gmail.com>