File size: 4,958 Bytes
4a285f6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import torch
import torch.nn as nn
import torch.nn.functional as functional

try:
    from queue import Queue
except ImportError:
    from Queue import Queue

from .functions import *


class ABN(nn.Module):
    """Activated Batch Normalization

    This gathers a `BatchNorm2d` and an activation function in a single module
    """

    def __init__(self, num_features, eps=1e-5, momentum=0.1, affine=True, activation="leaky_relu", slope=0.01):
        """Creates an Activated Batch Normalization module

        Parameters
        ----------
        num_features : int
            Number of feature channels in the input and output.
        eps : float
            Small constant to prevent numerical issues.
        momentum : float
            Momentum factor applied to compute running statistics as.
        affine : bool
            If `True` apply learned scale and shift transformation after normalization.
        activation : str
            Name of the activation functions, one of: `leaky_relu`, `elu` or `none`.
        slope : float
            Negative slope for the `leaky_relu` activation.
        """
        super(ABN, self).__init__()
        self.num_features = num_features
        self.affine = affine
        self.eps = eps
        self.momentum = momentum
        self.activation = activation
        self.slope = slope
        if self.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.register_buffer('running_mean', torch.zeros(num_features))
        self.register_buffer('running_var', torch.ones(num_features))
        self.reset_parameters()

    def reset_parameters(self):
        nn.init.constant_(self.running_mean, 0)
        nn.init.constant_(self.running_var, 1)
        if self.affine:
            nn.init.constant_(self.weight, 1)
            nn.init.constant_(self.bias, 0)

    def forward(self, x):
        x = functional.batch_norm(x, self.running_mean, self.running_var, self.weight, self.bias,
                                  self.training, self.momentum, self.eps)

        if self.activation == ACT_RELU:
            return functional.relu(x, inplace=True)
        elif self.activation == ACT_LEAKY_RELU:
            return functional.leaky_relu(x, negative_slope=self.slope, inplace=True)
        elif self.activation == ACT_ELU:
            return functional.elu(x, inplace=True)
        else:
            return x

    def __repr__(self):
        rep = '{name}({num_features}, eps={eps}, momentum={momentum},' \
              ' affine={affine}, activation={activation}'
        if self.activation == "leaky_relu":
            rep += ', slope={slope})'
        else:
            rep += ')'
        return rep.format(name=self.__class__.__name__, **self.__dict__)


class InPlaceABN(ABN):
    """InPlace Activated Batch Normalization"""

    def __init__(self, num_features, eps=1e-5, momentum=0.1, affine=True, activation="leaky_relu", slope=0.01):
        """Creates an InPlace Activated Batch Normalization module

        Parameters
        ----------
        num_features : int
            Number of feature channels in the input and output.
        eps : float
            Small constant to prevent numerical issues.
        momentum : float
            Momentum factor applied to compute running statistics as.
        affine : bool
            If `True` apply learned scale and shift transformation after normalization.
        activation : str
            Name of the activation functions, one of: `leaky_relu`, `elu` or `none`.
        slope : float
            Negative slope for the `leaky_relu` activation.
        """
        super(InPlaceABN, self).__init__(num_features, eps, momentum, affine, activation, slope)

    def forward(self, x):
        x, _, _ = inplace_abn(x, self.weight, self.bias, self.running_mean, self.running_var,
                           self.training, self.momentum, self.eps, self.activation, self.slope)
        return x


class InPlaceABNSync(ABN):
    """InPlace Activated Batch Normalization with cross-GPU synchronization
    This assumes that it will be replicated across GPUs using the same mechanism as in `nn.DistributedDataParallel`.
    """

    def forward(self, x):
        x, _, _ =  inplace_abn_sync(x, self.weight, self.bias, self.running_mean, self.running_var,
                                   self.training, self.momentum, self.eps, self.activation, self.slope)
        return x

    def __repr__(self):
        rep = '{name}({num_features}, eps={eps}, momentum={momentum},' \
              ' affine={affine}, activation={activation}'
        if self.activation == "leaky_relu":
            rep += ', slope={slope})'
        else:
            rep += ')'
        return rep.format(name=self.__class__.__name__, **self.__dict__)