File size: 15,166 Bytes
76d61a0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
from __future__ import annotations

import torch
from torch import nn
import torch.nn.functional as F


class CIBCELoss(nn.Module):
    def __init__(
        self,
        output_key: str = "ci",
        label_key: str = "ci",
        weight: float = 1.0,
        eps: float = 1e-6,
    ):
        super().__init__()
        self.output_key = str(output_key)
        self.label_key = str(label_key)
        self.weight = float(weight)
        self.eps = float(eps)

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        preds = torch.clamp(outputs[self.output_key].float(), self.eps, 1.0 - self.eps)
        targets = labels[self.label_key].float()
        if targets.ndim == 4 and targets.shape[1] == 1:
            targets = targets[:, 0]
        loss = self.weight * F.binary_cross_entropy(preds, targets)
        self.last_components = {"bce": float(loss.detach().cpu())}
        return loss


class CIFocalLoss(nn.Module):
    def __init__(
        self,
        output_key: str = "ci",
        label_key: str = "ci",
        weight: float = 1.0,
        alpha: float = 0.25,
        gamma: float = 2.0,
        eps: float = 1e-6,
    ):
        super().__init__()
        self.output_key = str(output_key)
        self.label_key = str(label_key)
        self.weight = float(weight)
        self.alpha = float(alpha)
        self.gamma = float(gamma)
        self.eps = float(eps)

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        preds = torch.clamp(outputs[self.output_key].float(), self.eps, 1.0 - self.eps)
        targets = labels[self.label_key].float().clamp(0.0, 1.0)
        if targets.ndim == 4 and targets.shape[1] == 1:
            targets = targets[:, 0]

        bce = F.binary_cross_entropy(preds, targets, reduction="none")
        pt = targets * preds + (1.0 - targets) * (1.0 - preds)
        alpha_t = targets * self.alpha + (1.0 - targets) * (1.0 - self.alpha)
        loss = self.weight * (alpha_t * (1.0 - pt).pow(self.gamma) * bce).mean()
        self.last_components = {"focal": float(loss.detach().cpu())}
        return loss


class CIFocalTverskyLoss(nn.Module):
    def __init__(
        self,
        output_key: str = "ci",
        label_key: str = "ci",
        weight: float = 1.0,
        focal_weight: float = 0.5,
        tversky_weight: float = 0.5,
        fp_weight: float = 0.7,
        fn_weight: float = 0.3,
        focal_gamma: float = 2.0,
        tversky_gamma: float = 1.0,
        positive_alpha: float = 0.35,
        target_threshold: float = 0.5,
        eps: float = 1e-6,
    ):
        super().__init__()
        self.output_key = str(output_key)
        self.label_key = str(label_key)
        self.weight = float(weight)
        self.focal_weight = float(focal_weight)
        self.tversky_weight = float(tversky_weight)
        self.fp_weight = float(fp_weight)
        self.fn_weight = float(fn_weight)
        self.focal_gamma = float(focal_gamma)
        self.tversky_gamma = float(tversky_gamma)
        self.positive_alpha = float(positive_alpha)
        self.target_threshold = float(target_threshold)
        self.eps = float(eps)

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        probs = torch.clamp(outputs[self.output_key].float(), self.eps, 1.0 - self.eps)
        targets = labels[self.label_key].float().clamp(0.0, 1.0)
        if targets.ndim == 4 and targets.shape[1] == 1:
            targets = targets[:, 0]

        bce = F.binary_cross_entropy(probs, targets, reduction="none")
        pt = targets * probs + (1.0 - targets) * (1.0 - probs)
        alpha_t = targets * self.positive_alpha + (1.0 - targets) * (1.0 - self.positive_alpha)
        focal = alpha_t * (1.0 - pt).pow(self.focal_gamma) * bce
        focal_loss = focal.mean()

        reduce_dims = tuple(range(1, probs.dim()))
        y_hard = (targets >= self.target_threshold).float()
        tp = (probs * y_hard).sum(dim=reduce_dims)
        fp = (probs * (1.0 - y_hard)).sum(dim=reduce_dims)
        fn = ((1.0 - probs) * y_hard).sum(dim=reduce_dims)
        tversky = (tp + self.eps) / (tp + self.fp_weight * fp + self.fn_weight * fn + self.eps)
        tversky_loss = (1.0 - tversky).pow(self.tversky_gamma).mean()

        loss = self.focal_weight * focal_loss + self.tversky_weight * tversky_loss
        total = self.weight * loss
        self.last_components = {
            "focal": float((self.weight * self.focal_weight * focal_loss).detach().cpu()),
            "tversky": float((self.weight * self.tversky_weight * tversky_loss).detach().cpu()),
            "total": float(total.detach().cpu()),
        }
        return total


class BTMaskedSmoothL1Loss(nn.Module):
    def __init__(
        self,
        output_key: str = "bt",
        label_key: str = "bt",
        weight: float = 1.0,
        lead_weights: list[float] | None = None,
        beta: float = 1.0,
    ):
        super().__init__()
        self.output_key = str(output_key)
        self.label_key = str(label_key)
        self.weight = float(weight)
        self.beta = float(beta)
        self.register_buffer("lead_weights", torch.tensor(lead_weights or [], dtype=torch.float32), persistent=False)

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        preds = outputs[self.output_key].float()
        targets = labels[self.label_key].float()
        valid = torch.isfinite(targets)
        if not bool(valid.any()):
            zero = preds.sum() * 0.0
            self.last_components = {"bt_smooth_l1": 0.0}
            return zero

        loss = F.smooth_l1_loss(preds, torch.nan_to_num(targets), beta=self.beta, reduction="none")
        if self.lead_weights.numel() > 0:
            if self.lead_weights.numel() != preds.shape[1]:
                raise ValueError(f"lead_weights length {self.lead_weights.numel()} != T {preds.shape[1]}")
            view_shape = (1, preds.shape[1]) + (1,) * (preds.ndim - 2)
            loss = loss * self.lead_weights.to(preds.device).view(view_shape)
        loss = self.weight * loss[valid].mean()
        self.last_components = {"bt_smooth_l1": float(loss.detach().cpu())}
        return loss


class BTMaskedMSELoss(nn.Module):
    def __init__(
        self,
        output_key: str = "bt",
        label_key: str = "bt",
        weight: float = 1.0,
        lead_weights: list[float] | None = None,
    ):
        super().__init__()
        self.output_key = str(output_key)
        self.label_key = str(label_key)
        self.weight = float(weight)
        self.register_buffer("lead_weights", torch.tensor(lead_weights or [], dtype=torch.float32), persistent=False)

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        preds = outputs[self.output_key].float()
        targets = labels[self.label_key].float()
        valid = torch.isfinite(targets)
        if not bool(valid.any()):
            zero = preds.sum() * 0.0
            self.last_components = {"bt_mse": 0.0}
            return zero

        loss = (preds - torch.nan_to_num(targets)) ** 2
        if self.lead_weights.numel() > 0:
            if self.lead_weights.numel() != preds.shape[1]:
                raise ValueError(f"lead_weights length {self.lead_weights.numel()} != T {preds.shape[1]}")
            view_shape = (1, preds.shape[1]) + (1,) * (preds.ndim - 2)
            loss = loss * self.lead_weights.to(preds.device).view(view_shape)
        loss = self.weight * loss[valid].mean()
        self.last_components = {"bt_mse": float(loss.detach().cpu())}
        return loss


class CIBTLoss(nn.Module):
    def __init__(
        self,
        ci_loss: dict,
        bt_loss: dict | None = None,
        normalize_terms: bool = False,
        ref_batches: int = 100,
        eps: float = 1e-8,
    ):
        super().__init__()
        ci_cfg = dict(ci_loss)
        bt_cfg = dict(bt_loss or {"name": "bt_mse", "weight": 0.05})
        self.ci_weight = float(ci_cfg.pop("weight", 1.0))
        self.bt_weight = float(bt_cfg.pop("weight", 1.0))
        self.ci_loss = _build_one_loss(ci_cfg, default_name=str(ci_cfg.get("name", "bce")))
        self.bt_loss = _build_one_loss(bt_cfg, default_name="bt_mse")
        self.normalize_terms = bool(normalize_terms)
        self.ref_batches = int(ref_batches)
        self.eps = float(eps)
        self.register_buffer("ref_count", torch.tensor(0.0), persistent=True)
        self.register_buffer("ci_ref_sum", torch.tensor(0.0), persistent=True)
        self.register_buffer("bt_ref_sum", torch.tensor(0.0), persistent=True)
        self.register_buffer("ci_ref", torch.tensor(1.0), persistent=True)
        self.register_buffer("bt_ref", torch.tensor(1.0), persistent=True)
        self.last_components: dict[str, float] = {}

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        ci = self.ci_loss(outputs, labels)
        bt = self.bt_loss(outputs, labels)
        if self.normalize_terms:
            self._update_refs(ci, bt)
            ci_term = ci / self.ci_ref.clamp_min(self.eps)
            bt_term = bt / self.bt_ref.clamp_min(self.eps)
        else:
            ci_term = ci
            bt_term = bt
        ci_weighted = self.ci_weight * ci_term
        bt_weighted = self.bt_weight * bt_term
        total = ci_weighted + bt_weighted

        components = {
            "ci": float(ci_weighted.detach().cpu()),
            "bt": float(bt_weighted.detach().cpu()),
            "total": float(total.detach().cpu()),
            "ci_raw": float(ci.detach().cpu()),
            "bt_raw": float(bt.detach().cpu()),
            "ci_norm": float(ci_term.detach().cpu()),
            "bt_norm": float(bt_term.detach().cpu()),
            "ci_weight": float(self.ci_weight),
            "bt_weight": float(self.bt_weight),
            "ci_ref": float(self.ci_ref.detach().cpu()),
            "bt_ref": float(self.bt_ref.detach().cpu()),
            "ref_count": float(self.ref_count.detach().cpu()),
            "ref_ready": float(self._ref_ready()),
        }
        for name, value in getattr(self.ci_loss, "last_components", {}).items():
            components[f"ci_{name}"] = float(value)
        for name, value in getattr(self.bt_loss, "last_components", {}).items():
            component_name = str(name) if str(name).startswith("bt_") else f"bt_{name}"
            components[component_name] = float(value)
        self.last_components = components
        return total

    def _ref_ready(self) -> bool:
        return bool(self.normalize_terms and self.ref_count.item() >= max(self.ref_batches, 1))

    def _update_refs(self, ci: torch.Tensor, bt: torch.Tensor) -> None:
        if self.ref_batches <= 0:
            if self.ref_count.item() < 1:
                self.ci_ref.copy_(ci.detach().abs().clamp_min(self.eps))
                self.bt_ref.copy_(bt.detach().abs().clamp_min(self.eps))
                self.ref_count.fill_(1.0)
            return
        if self.ref_count.item() >= self.ref_batches:
            return
        self.ci_ref_sum.add_(ci.detach().abs())
        self.bt_ref_sum.add_(bt.detach().abs())
        self.ref_count.add_(1.0)
        denom = self.ref_count.clamp_min(1.0)
        self.ci_ref.copy_((self.ci_ref_sum / denom).clamp_min(self.eps))
        self.bt_ref.copy_((self.bt_ref_sum / denom).clamp_min(self.eps))


class CombinedLoss(nn.Module):
    def __init__(self, losses: dict[str, nn.Module]):
        super().__init__()
        if not losses:
            raise ValueError("CombinedLoss requires at least one loss")
        self.losses = nn.ModuleDict(losses)
        self.last_components: dict[str, float] = {}

    def forward(self, outputs: dict[str, torch.Tensor], labels: dict[str, torch.Tensor]) -> torch.Tensor:
        total = None
        components = {}
        for name, loss_fn in self.losses.items():
            value = loss_fn(outputs, labels)
            components[name] = float(value.detach().cpu())
            for sub_name, sub_value in getattr(loss_fn, "last_components", {}).items():
                component_name = str(sub_name) if name == "loss" else f"{name}_{sub_name}"
                components[component_name] = float(sub_value)
            total = value if total is None else total + value
        self.last_components = components
        if total is None:
            raise RuntimeError("no losses were evaluated")
        return total


def build_loss(config: dict) -> nn.Module:
    config = dict(config)
    if str(config.get("name", "")).lower() == "ci_bt":
        return _build_one_loss(config, default_name="ci_bt")
    if "losses" in config:
        return CombinedLoss(
            {
                str(component_name): _build_one_loss(dict(component_cfg), default_name=str(component_name))
                for component_name, component_cfg in dict(config["losses"]).items()
            }
        )
    return CombinedLoss({"loss": _build_one_loss(config, default_name=str(config.get("name", "binary_focal")))})


def _build_one_loss(config: dict, default_name: str) -> nn.Module:
    name = str(config.get("name", default_name)).lower()
    params = dict(config.get("params", {}))
    output_key = str(config.get("output_key", "bt" if name.startswith("bt") or "smooth_l1" in name else "ci"))
    label_key = str(config.get("label_key", config.get("target_label", output_key)))
    weight = float(config.get("weight", 1.0))

    if name in {"bce", "binary_bce", "binary_cross_entropy", "ci_bce"}:
        return CIBCELoss(output_key=output_key, label_key=label_key, weight=weight, **params)
    if name in {"binary_focal", "focal", "binary_focal_loss", "ci", "ci_focal"}:
        return CIFocalLoss(output_key=output_key, label_key=label_key, weight=weight, **params)
    if name in {"focal_tversky", "tversky_focal", "ci_focal_tversky", "far_aware_tversky_focal", "far_aware", "ci_far_aware"}:
        return CIFocalTverskyLoss(output_key=output_key, label_key=label_key, weight=weight, **params)
    if name in {"masked_lead_smooth_l1", "bt_smooth_l1", "bt", "bt_masked_smooth_l1"}:
        return BTMaskedSmoothL1Loss(output_key=output_key, label_key=label_key, weight=weight, **params)
    if name in {"bt_mse", "masked_bt_mse", "bt_masked_mse"}:
        return BTMaskedMSELoss(output_key=output_key, label_key=label_key, weight=weight, **params)
    if name == "ci_bt":
        if "ci_loss" not in config:
            raise ValueError("ci_bt loss requires a ci_loss config block")
        bt_loss = config.get("bt_loss")
        if bt_loss is None:
            bt_loss = {
                "name": "bt_mse",
                "output_key": config.get("bt_output_key", "bt"),
                "label_key": config.get("bt_label_key", "bt"),
                "weight": config.get("bt_weight", 0.05),
            }
        return CIBTLoss(
            ci_loss=dict(config["ci_loss"]),
            bt_loss=dict(bt_loss),
            **params,
        )
    raise ValueError(f"unknown loss: {name}")