Class: DNN::Losses::SoftmaxCrossEntropy

Inherits:
Loss
  • Object
show all
Defined in:
lib/dnn/core/losses.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Loss

#forward, #regularizes_backward, #to_hash

Class Method Details

.softmax(x) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 103

def self.softmax(x)
  NMath.exp(x) / NMath.exp(x).sum(1).reshape(x.shape[0], 1)
end

Instance Method Details

#backward(y) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 113

def backward(y)
  @out - y
end

#loss(x, y) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 107

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