File size: 11,625 Bytes
ce7bf5b
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# Copyright Generate Biomedicines, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import torch
import torch.nn as nn
"""
对3d数据进行归一化
"""


class MaskedBatchNorm1d(nn.Module):
    """A masked version of nn.BatchNorm1d. Only tested for 3D inputs.

    Args:
        num_features (int): :math:`C` from an expected input of size
            :math:`(N, C, L)`
        eps (float): a value added to the denominator for numerical stability.
            Default: 1e-5
        momentum (float): the value used for the running_mean and running_var
            computation. Can be set to ``None`` for cumulative moving average
            (i.e. simple average). Default: 0.1
        affine (bool): a boolean value that when set to ``True``, this module has
            learnable affine parameters. Default: ``True``
        track_running_stats (bool) : a boolean value that when set to ``True``, this
            module tracks the running mean and variance, and when set to ``False``,
            this module does not track such statistics and always uses batch
            statistics in both training and eval modes. Default: ``True``

    Inputs:
        x (torch.tensor): of size (batch_size, num_features, sequence_length)
        input_mask (torch.tensor or None) : (optional) of dtype (byte) or (bool) of shape (batch_size, 1, sequence_length) zeroes (or False) indicate positions that cannot contribute to computation
    Outputs:
        y (torch.tensor): of size (batch_size, num_features, sequence_length)
    """

    def __init__(
        self,
        num_features,
        eps=1e-5,
        momentum=0.1,
        affine=True,
        track_running_stats=True,
    ):
        super(MaskedBatchNorm1d, self).__init__()
        self.num_features = num_features
        self.eps = eps
        self.momentum = momentum
        self.affine = affine
        if affine:
            self.weight = nn.Parameter(torch.Tensor(num_features, 1))
            self.bias = nn.Parameter(torch.Tensor(num_features, 1))
        else:
            self.register_parameter("weight", None)
            self.register_parameter("bias", None)
        self.track_running_stats = track_running_stats
        if self.track_running_stats:
            self.register_buffer("running_mean", torch.zeros(num_features, 1))
            self.register_buffer("running_var", torch.ones(num_features, 1))
            self.register_buffer(
                "num_batches_tracked", torch.tensor(0, dtype=torch.long)
            )
        else:
            self.register_parameter("running_mean", None)
            self.register_parameter("running_var", None)
            self.register_parameter("num_batches_tracked", None)
        self.reset_parameters()

    def reset_running_stats(self):
        if self.track_running_stats:
            self.running_mean.zero_()
            self.running_var.fill_(1)
            self.num_batches_tracked.zero_()

    def reset_parameters(self):
        self.reset_running_stats()
        if self.affine:
            nn.init.ones_(self.weight)
            nn.init.zeros_(self.bias)

    def forward(self, input, input_mask=None):
        # Calculate the masked mean and variance
        B, C, L = input.shape
        if input_mask is not None and input_mask.shape != (B, 1, L):
            raise ValueError("Mask should have shape (B, 1, L).")
        if C != self.num_features:
            raise ValueError(
                "Expected %d channels but input has %d channels"
                % (self.num_features, C)
            )
        if input_mask is not None:
            masked = input * input_mask
            n = input_mask.sum()
        else:
            masked = input
            n = B * L
        # Sum
        masked_sum = masked.sum(dim=0, keepdim=True).sum(dim=2, keepdim=True)
        # Divide by sum of mask
        current_mean = masked_sum / n
        current_var = ((masked - current_mean) ** 2).sum(dim=0, keepdim=True).sum(
            dim=2, keepdim=True
        ) / n
        # Update running stats
        if self.track_running_stats and self.training:
            if self.num_batches_tracked == 0:
                self.running_mean = current_mean
                self.running_var = current_var
            else:
                self.running_mean = (
                    1 - self.momentum
                ) * self.running_mean + self.momentum * current_mean
                self.running_var = (
                    1 - self.momentum
                ) * self.running_var + self.momentum * current_var
            self.num_batches_tracked += 1
        # Norm the input
        if self.track_running_stats and not self.training:
            normed = (masked - self.running_mean) / (
                torch.sqrt(self.running_var + self.eps)
            )
        else:
            normed = (masked - current_mean) / (torch.sqrt(current_var + self.eps))
        # Apply affine parameters
        if self.affine:
            normed = normed * self.weight + self.bias
        return normed


class MaskedBatchNorm2d(nn.Module):
    """A masked version of nn.BatchNorm1d. Only tested for 3D inputs.

    Args:
        num_features (int): :math:`C` from an expected input of size
            :math:`(N, C, L)`
        eps (float): a value added to the denominator for numerical stability.
            Default: 1e-5
        momentum (float): the value used for the running_mean and running_var
            computation. Can be set to ``None`` for cumulative moving average
            (i.e. simple average). Default: 0.1
        affine (bool): a boolean value that when set to ``True``, this module has
            learnable affine parameters. Default: ``True``
        track_running_stats (bool) : a boolean value that when set to ``True``, this
            module tracks the running mean and variance, and when set to ``False``,
            this module does not track such statistics and always uses batch
            statistics in both training and eval modes. Default: ``True``

    Inputs:
        x (torch.tensor): of size (batch_size, num_features, sequence_length)
        input_mask (torch.tensor or None) : (optional) of dtype (byte) or (bool) of shape (batch_size, 1, sequence_length) zeroes (or False) indicate positions that cannot contribute to computation
    Outputs:
        y (torch.tensor): of size (batch_size, num_features, sequence_length)
    """

    def __init__(
        self,
        num_features,
        eps=1e-5,
        momentum=0.1,
        affine=True,
        track_running_stats=True,
    ):
        super().__init__()
        self.num_features = num_features
        self.eps = eps
        self.momentum = momentum
        self.affine = affine
        if affine:
            self.weight = nn.Parameter(torch.ones(num_features,))
            self.bias = nn.Parameter(torch.zeros(num_features,))
        else:
            self.register_parameter("weight", None)
            self.register_parameter("bias", None)
        self.track_running_stats = track_running_stats
        if self.track_running_stats:
            self.register_buffer("running_mean", torch.zeros(1, 1, 1, num_features))
            self.register_buffer("running_var", torch.ones(1, 1, 1, num_features))
            self.register_buffer(
                "num_batches_tracked", torch.tensor(0, dtype=torch.long)
            )
        else:
            self.register_parameter("running_mean", None)
            self.register_parameter("running_var", None)
            self.register_parameter("num_batches_tracked", None)
        self.reset_parameters()

    def reset_running_stats(self):
        if self.track_running_stats:
            self.running_mean.zero_()
            self.running_var.fill_(1)
            self.num_batches_tracked.zero_()

    def reset_parameters(self):
        self.reset_running_stats()
        if self.affine:
            nn.init.ones_(self.weight)
            nn.init.zeros_(self.bias)

    def forward(self, input, mask=None):
        # Calculate the masked mean and variance
        B, L, L, C = input.size()
        if mask is not None:
            if mask.dim() != 4:
                raise ValueError(
                    f"Input mask must have four dimensions, but has {mask.dim()}"
                )
            b, l, l, d = mask.size()
            if (b != B) or (l != L):
                raise ValueError(
                    f"Input mask must have shape {(B, L, L, 1)} or {(B, L, L, C)} to match input."
                )
            if d == 1:
                mask = mask.expand(input.size())

        if C != self.num_features:
            raise ValueError(
                "Expected %d channels but input has %d channels"
                % (self.num_features, C)
            )

        if mask is None:
            mask = input.new_ones(input.size())

        masked = input * mask
        n = mask.sum(dim=(0, 1, 2), keepdim=True)
        masked_sum = (masked).sum(dim=(0, 1, 2), keepdim=True)

        current_mean = masked_sum / n
        current_var = (mask * (masked - current_mean).pow(2)).sum(
            dim=(0, 1, 2), keepdim=True
        ) / n
        # Update running stats
        with torch.no_grad():
            if self.track_running_stats and self.training:
                if self.num_batches_tracked == 0:
                    self.running_mean = current_mean.detach()
                    self.running_var = current_var.detach()
                else:
                    self.running_mean = (
                        1 - self.momentum
                    ) * self.running_mean + self.momentum * current_mean.detach()
                    self.running_var = (
                        1 - self.momentum
                    ) * self.running_var + self.momentum * current_var.detach()
                self.num_batches_tracked += 1
        # Norm the input
        if self.track_running_stats and not self.training:
            normed = (masked - self.running_mean) / (
                torch.sqrt(self.running_var + self.eps)
            )
        else:
            normed = (masked - current_mean) / (torch.sqrt(current_var + self.eps))
        # Apply affine parameters
        if self.affine:
            normed = normed * self.weight + self.bias

        normed = normed * mask
        return normed


class NormedReductionLayer(nn.Module):
    """A ReductionLayer with LayerNorms after the hidden layers."""

    def __init__(self, input_dim, hidden_dim, output_dim, dropout=0.0):
        super().__init__()
        self.d1 = nn.Dropout(p=dropout)
        self.d2 = nn.Dropout(p=dropout)
        self.hidden = nn.Linear(input_dim, hidden_dim)
        self.relu = nn.ReLU()
        self.output = nn.Linear(hidden_dim, output_dim)
        self.norm1 = nn.LayerNorm(input_dim)
        self.norm2 = nn.LayerNorm(hidden_dim)

    def reduce(self, x, mask):
        masked_x = x * mask
        mean_x = masked_x.sum(dim=1) / torch.sum(mask, dim=1)
        return mean_x

    def forward(self, x, mask):
        reduced_x = self.norm1(self.reduce(x, mask))
        h = self.norm2(self.hidden(reduced_x))
        return self.output(self.relu(h))