|
1 | | -import torch |
2 | | -import torch.nn as nn |
3 | | - |
4 | | - |
5 | | -class AsymmetricLossMultiLabel(nn.Module): |
6 | | - def __init__(self, gamma_neg=4, gamma_pos=1, clip=0.05, eps=1e-8, disable_torch_grad_focal_loss=False): |
7 | | - super(AsymmetricLossMultiLabel, self).__init__() |
8 | | - |
9 | | - self.gamma_neg = gamma_neg |
10 | | - self.gamma_pos = gamma_pos |
11 | | - self.clip = clip |
12 | | - self.disable_torch_grad_focal_loss = disable_torch_grad_focal_loss |
13 | | - self.eps = eps |
14 | | - |
15 | | - def forward(self, x, y): |
16 | | - """" |
17 | | - Parameters |
18 | | - ---------- |
19 | | - x: input logits |
20 | | - y: targets (multi-label binarized vector) |
21 | | - """ |
22 | | - |
23 | | - # Calculating Probabilities |
24 | | - x_sigmoid = torch.sigmoid(x) |
25 | | - xs_pos = x_sigmoid |
26 | | - xs_neg = 1 - x_sigmoid |
27 | | - |
28 | | - # Asymmetric Clipping |
29 | | - if self.clip is not None and self.clip > 0: |
30 | | - xs_neg = (xs_neg + self.clip).clamp(max=1) |
31 | | - |
32 | | - # Basic CE calculation |
33 | | - los_pos = y * torch.log(xs_pos.clamp(min=self.eps)) |
34 | | - los_neg = (1 - y) * torch.log(xs_neg.clamp(min=self.eps)) |
35 | | - loss = los_pos + los_neg |
36 | | - |
37 | | - # Asymmetric Focusing |
38 | | - if self.gamma_neg > 0 or self.gamma_pos > 0: |
39 | | - if self.disable_torch_grad_focal_loss: |
40 | | - torch._C.set_grad_enabled(False) |
41 | | - pt0 = xs_pos * y |
42 | | - pt1 = xs_neg * (1 - y) # pt = p if t > 0 else 1-p |
43 | | - pt = pt0 + pt1 |
44 | | - one_sided_gamma = self.gamma_pos * y + self.gamma_neg * (1 - y) |
45 | | - one_sided_w = torch.pow(1 - pt, one_sided_gamma) |
46 | | - if self.disable_torch_grad_focal_loss: |
47 | | - torch._C.set_grad_enabled(True) |
48 | | - loss *= one_sided_w |
49 | | - |
50 | | - return -loss.sum() |
51 | | - |
52 | | - |
53 | | -class AsymmetricLossSingleLabel(nn.Module): |
54 | | - def __init__(self, gamma_pos=1, gamma_neg=4, eps: float = 0.1, reduction='mean'): |
55 | | - super(AsymmetricLossSingleLabel, self).__init__() |
56 | | - |
57 | | - self.eps = eps |
58 | | - self.logsoftmax = nn.LogSoftmax(dim=-1) |
59 | | - self.targets_classes = [] # prevent gpu repeated memory allocation |
60 | | - self.gamma_pos = gamma_pos |
61 | | - self.gamma_neg = gamma_neg |
62 | | - self.reduction = reduction |
63 | | - |
64 | | - def forward(self, inputs, target, reduction=None): |
65 | | - """" |
66 | | - Parameters |
67 | | - ---------- |
68 | | - x: input logits |
69 | | - y: targets (1-hot vector) |
70 | | - """ |
71 | | - |
72 | | - num_classes = inputs.size()[-1] |
73 | | - log_preds = self.logsoftmax(inputs) |
74 | | - self.targets_classes = torch.zeros_like(inputs).scatter_(1, target.long().unsqueeze(1), 1) |
75 | | - |
76 | | - # ASL weights |
77 | | - targets = self.targets_classes |
78 | | - anti_targets = 1 - targets |
79 | | - xs_pos = torch.exp(log_preds) |
80 | | - xs_neg = 1 - xs_pos |
81 | | - xs_pos = xs_pos * targets |
82 | | - xs_neg = xs_neg * anti_targets |
83 | | - asymmetric_w = torch.pow(1 - xs_pos - xs_neg, |
84 | | - self.gamma_pos * targets + self.gamma_neg * anti_targets) |
85 | | - log_preds = log_preds * asymmetric_w |
86 | | - |
87 | | - if self.eps > 0: # label smoothing |
88 | | - self.targets_classes = self.targets_classes.mul(1 - self.eps).add(self.eps / num_classes) |
89 | | - |
90 | | - # loss calculation |
91 | | - loss = - self.targets_classes.mul(log_preds) |
92 | | - |
93 | | - loss = loss.sum(dim=-1) |
94 | | - if self.reduction == 'mean': |
95 | | - loss = loss.mean() |
96 | | - |
97 | | - return loss |
| 1 | +import torch |
| 2 | +import torch.nn as nn |
| 3 | + |
| 4 | + |
| 5 | +class AsymmetricLossMultiLabel(nn.Module): |
| 6 | + def __init__(self, gamma_neg=4, gamma_pos=1, clip=0.05, eps=1e-8, disable_torch_grad_focal_loss=False): |
| 7 | + super(AsymmetricLossMultiLabel, self).__init__() |
| 8 | + |
| 9 | + self.gamma_neg = gamma_neg |
| 10 | + self.gamma_pos = gamma_pos |
| 11 | + self.clip = clip |
| 12 | + self.disable_torch_grad_focal_loss = disable_torch_grad_focal_loss |
| 13 | + self.eps = eps |
| 14 | + |
| 15 | + def forward(self, x, y): |
| 16 | + """" |
| 17 | + Parameters |
| 18 | + ---------- |
| 19 | + x: input logits |
| 20 | + y: targets (multi-label binarized vector) |
| 21 | + """ |
| 22 | + |
| 23 | + # Calculating Probabilities |
| 24 | + x_sigmoid = torch.sigmoid(x) |
| 25 | + xs_pos = x_sigmoid |
| 26 | + xs_neg = 1 - x_sigmoid |
| 27 | + |
| 28 | + # Asymmetric Clipping |
| 29 | + if self.clip is not None and self.clip > 0: |
| 30 | + xs_neg = (xs_neg + self.clip).clamp(max=1) |
| 31 | + |
| 32 | + # Basic CE calculation |
| 33 | + los_pos = y * torch.log(xs_pos.clamp(min=self.eps)) |
| 34 | + los_neg = (1 - y) * torch.log(xs_neg.clamp(min=self.eps)) |
| 35 | + loss = los_pos + los_neg |
| 36 | + |
| 37 | + # Asymmetric Focusing |
| 38 | + if self.gamma_neg > 0 or self.gamma_pos > 0: |
| 39 | + if self.disable_torch_grad_focal_loss: |
| 40 | + torch.set_grad_enabled(False) |
| 41 | + pt0 = xs_pos * y |
| 42 | + pt1 = xs_neg * (1 - y) # pt = p if t > 0 else 1-p |
| 43 | + pt = pt0 + pt1 |
| 44 | + one_sided_gamma = self.gamma_pos * y + self.gamma_neg * (1 - y) |
| 45 | + one_sided_w = torch.pow(1 - pt, one_sided_gamma) |
| 46 | + if self.disable_torch_grad_focal_loss: |
| 47 | + torch.set_grad_enabled(True) |
| 48 | + loss *= one_sided_w |
| 49 | + |
| 50 | + return -loss.sum() |
| 51 | + |
| 52 | + |
| 53 | +class AsymmetricLossSingleLabel(nn.Module): |
| 54 | + def __init__(self, gamma_pos=1, gamma_neg=4, eps: float = 0.1, reduction='mean'): |
| 55 | + super(AsymmetricLossSingleLabel, self).__init__() |
| 56 | + |
| 57 | + self.eps = eps |
| 58 | + self.logsoftmax = nn.LogSoftmax(dim=-1) |
| 59 | + self.targets_classes = [] # prevent gpu repeated memory allocation |
| 60 | + self.gamma_pos = gamma_pos |
| 61 | + self.gamma_neg = gamma_neg |
| 62 | + self.reduction = reduction |
| 63 | + |
| 64 | + def forward(self, inputs, target, reduction=None): |
| 65 | + """" |
| 66 | + Parameters |
| 67 | + ---------- |
| 68 | + x: input logits |
| 69 | + y: targets (1-hot vector) |
| 70 | + """ |
| 71 | + |
| 72 | + num_classes = inputs.size()[-1] |
| 73 | + log_preds = self.logsoftmax(inputs) |
| 74 | + self.targets_classes = torch.zeros_like(inputs).scatter_(1, target.long().unsqueeze(1), 1) |
| 75 | + |
| 76 | + # ASL weights |
| 77 | + targets = self.targets_classes |
| 78 | + anti_targets = 1 - targets |
| 79 | + xs_pos = torch.exp(log_preds) |
| 80 | + xs_neg = 1 - xs_pos |
| 81 | + xs_pos = xs_pos * targets |
| 82 | + xs_neg = xs_neg * anti_targets |
| 83 | + asymmetric_w = torch.pow(1 - xs_pos - xs_neg, |
| 84 | + self.gamma_pos * targets + self.gamma_neg * anti_targets) |
| 85 | + log_preds = log_preds * asymmetric_w |
| 86 | + |
| 87 | + if self.eps > 0: # label smoothing |
| 88 | + self.targets_classes = self.targets_classes.mul(1 - self.eps).add(self.eps / num_classes) |
| 89 | + |
| 90 | + # loss calculation |
| 91 | + loss = - self.targets_classes.mul(log_preds) |
| 92 | + |
| 93 | + loss = loss.sum(dim=-1) |
| 94 | + if self.reduction == 'mean': |
| 95 | + loss = loss.mean() |
| 96 | + |
| 97 | + return loss |
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