Class: DNN::Activations::SigmoidWithLoss

Inherits:
OutputLayer
  • Object
show all
Includes:
Numo
Defined in:
lib/dnn/core/activations.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ SigmoidWithLoss

Returns a new instance of SigmoidWithLoss.



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# File 'lib/dnn/core/activations.rb', line 111

def initialize
  @sigmoid = Sigmoid.new
end

Instance Method Details

#backward(y) ⇒ Object 



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# File 'lib/dnn/core/activations.rb', line 119

def backward(y)
  @out - y
end

#forward(x) ⇒ Object 



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# File 'lib/dnn/core/activations.rb', line 115

def forward(x)
  @out = @sigmoid.forward(x)
end

#loss(y) ⇒ Object 



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# File 'lib/dnn/core/activations.rb', line 123

def loss(y)
  batch_size = y.shape[0]
  -(y * NMath.log(@out + 1e-7) + (1 - y) * NMath.log(1 - @out + 1e-7)).sum / batch_size + ridge
end