Source code for torch.nn.modules.dropout

from .module import Module
from .. import functional as F


[docs]class Dropout(Module): r"""During training, randomly zeroes some of the elements of the input tensor with probability *p* using samples from a bernoulli distribution. The elements to zero are randomized on every forward call. This has proven to be an effective technique for regularization and preventing the co-adaptation of neurons as described in the paper `Improving neural networks by preventing co-adaptation of feature detectors`_ . Furthermore, the outputs are scaled by a factor of *1/(1-p)* during training. This means that during evaluation the module simply computes an identity function. Args: p: probability of an element to be zeroed. Default: 0.5 inplace: If set to True, will do this operation in-place. Default: false Shape: - Input: `Any`. Input can be of any shape - Output: `Same`. Output is of the same shape as input Examples:: >>> m = nn.Dropout(p=0.2) >>> input = autograd.Variable(torch.randn(20, 16)) >>> output = m(input) .. _Improving neural networks by preventing co-adaptation of feature detectors: https://arxiv.org/abs/1207.0580 """ def __init__(self, p=0.5, inplace=False): super(Dropout, self).__init__() if p < 0 or p > 1: raise ValueError("dropout probability has to be between 0 and 1, " "but got {}".format(p)) self.p = p self.inplace = inplace def forward(self, input): return F.dropout(input, self.p, self.training, self.inplace) def __repr__(self): inplace_str = ', inplace' if self.inplace else '' return self.__class__.__name__ + ' (' \ + 'p = ' + str(self.p) \ + inplace_str + ')'
[docs]class Dropout2d(Module): r"""Randomly zeroes whole channels of the input tensor. The channels to zero-out are randomized on every forward call. *Usually the input comes from Conv2d modules.* As described in the paper `Efficient Object Localization Using Convolutional Networks`_ , if adjacent pixels within feature maps are strongly correlated (as is normally the case in early convolution layers) then iid dropout will not regularize the activations and will otherwise just result in an effective learning rate decrease. In this case, :func:`nn.Dropout2d` will help promote independence between feature maps and should be used instead. Args: p (float, optional): probability of an element to be zeroed. inplace (bool, optional): If set to True, will do this operation in-place Shape: - Input: :math:`(N, C, H, W)` - Output: :math:`(N, C, H, W)` (same shape as input) Examples:: >>> m = nn.Dropout2d(p=0.2) >>> input = autograd.Variable(torch.randn(20, 16, 32, 32)) >>> output = m(input) .. _Efficient Object Localization Using Convolutional Networks: http://arxiv.org/abs/1411.4280 """ def __init__(self, p=0.5, inplace=False): super(Dropout2d, self).__init__() if p < 0 or p > 1: raise ValueError("dropout probability has to be between 0 and 1, " "but got {}".format(p)) self.p = p self.inplace = inplace def forward(self, input): return self._backend.Dropout2d(self.p, self.training, self.inplace)(input) def __repr__(self): inplace_str = ', inplace' if self.inplace else '' return self.__class__.__name__ + ' (' \ + 'p=' + str(self.p) \ + inplace_str + ')'
[docs]class Dropout3d(Module): r"""Randomly zeroes whole channels of the input tensor. The channels to zero are randomized on every forward call. *Usually the input comes from Conv3d modules.* As described in the paper `Efficient Object Localization Using Convolutional Networks`_ , if adjacent pixels within feature maps are strongly correlated (as is normally the case in early convolution layers) then iid dropout will not regularize the activations and will otherwise just result in an effective learning rate decrease. In this case, :func:`nn.Dropout3d` will help promote independence between feature maps and should be used instead. Args: p (float, optional): probability of an element to be zeroed. inplace (bool, optional): If set to True, will do this operation in-place Shape: - Input: :math:`(N, C, D, H, W)` - Output: :math:`(N, C, D, H, W)` (same shape as input) Examples:: >>> m = nn.Dropout3d(p=0.2) >>> input = autograd.Variable(torch.randn(20, 16, 4, 32, 32)) >>> output = m(input) .. _Efficient Object Localization Using Convolutional Networks: http://arxiv.org/abs/1411.4280 """ def __init__(self, p=0.5, inplace=False): super(Dropout3d, self).__init__() if p < 0 or p > 1: raise ValueError("dropout probability has to be between 0 and 1, " "but got {}".format(p)) self.p = p self.inplace = inplace def forward(self, input): return self._backend.Dropout3d(self.p, self.training, self.inplace)(input) def __repr__(self): inplace_str = ', inplace' if self.inplace else '' return self.__class__.__name__ + ' (' \ + 'p=' + str(self.p) \ + inplace_str + ')'
[docs]class AlphaDropout(Module): r"""Applies Alpha Dropout over the input. Alpha Dropout is a type of Dropout that maintains the self-normalizing property. For an input with zero mean and unit standard deviation, the output of Alpha Dropout maintains the original mean and standard deviation of the input. Alpha Dropout goes hand-in-hand with SELU activation function, which ensures that the outputs have zero mean and unit standard deviation. During training, it randomly masks some of the elements of the input tensor with probability *p* using samples from a bernoulli distribution. The elements to masked are randomized on every forward call, and scaled and shifted to maintain zero mean and unit standard deviation. During evaluation the module simply computes an identity function. More details can be found in the paper `Self-Normalizing Neural Networks`_ . Args: p (float): probability of an element to be dropped. Default: 0.5 Shape: - Input: `Any`. Input can be of any shape - Output: `Same`. Output is of the same shape as input Examples:: >>> m = nn.AlphaDropout(p=0.2) >>> input = autograd.Variable(torch.randn(20, 16)) >>> output = m(input) .. _Self-Normalizing Neural Networks: https://arxiv.org/abs/1706.02515 """ def __init__(self, p=0.5): super(AlphaDropout, self).__init__() if p < 0 or p > 1: raise ValueError("dropout probability has to be between 0 and 1, " "but got {}".format(p)) self.p = p def forward(self, input): return F.alpha_dropout(input, self.p, self.training) def __repr__(self): return self.__class__.__name__ + ' (' \ + 'p = ' + str(self.p) + ')'