mirror of
https://github.com/open-mmlab/mmclassification.git
synced 2025-06-03 21:53:55 +08:00
9578bfa0f1
* add focal loss * apply class wise sum * fix doctring * do not apply sum over classes and fix docstring * fix docstring * fix weight shape * fix weight shape
23 lines
615 B
Python
23 lines
615 B
Python
import torch
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from mmcls.models import build_loss
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def test_focal_loss():
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# test focal_loss
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cls_score = torch.Tensor([[5, -5, 0], [5, -5, 0]])
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label = torch.Tensor([[1, 0, 1], [0, 1, 0]])
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weight = torch.tensor([0.5, 0.5])
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loss_cfg = dict(
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type='FocalLoss',
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gamma=2.0,
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alpha=0.25,
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reduction='mean',
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loss_weight=1.0)
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loss = build_loss(loss_cfg)
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assert torch.allclose(loss(cls_score, label), torch.tensor(0.8522))
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# test focal_loss with weight
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assert torch.allclose(
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loss(cls_score, label, weight=weight), torch.tensor(0.8522 / 2))
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