Class: DNN::Losses::SigmoidCrossEntropy

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Loss

#loss, #regularizers_backward, #regularizers_forward

Constructor Details

#initialize(eps: 1e-7) ⇒ SigmoidCrossEntropy

Returns a new instance of SigmoidCrossEntropy.

Parameters:

  • eps (Float) (defaults to: 1e-7) —

    Value to avoid nan.



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# File 'lib/dnn/core/losses.rb', line 155

def initialize(eps: 1e-7)
  @eps = eps
end

Instance Attribute Details

#eps ⇒ Object

Returns the value of attribute eps.



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# File 'lib/dnn/core/losses.rb', line 148

def eps
  @eps
end

Class Method Details

.from_hash(hash) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 150

def self.from_hash(hash)
  self.new(eps: hash[:eps])
end

Instance Method Details

#backward(y, t) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 164

def backward(y, t)
  @x - t
end

#forward(y, t) ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 159

def forward(y, t)
  @x = Activations::Sigmoid.new.forward(y)
  -(t * Xumo::NMath.log(@x) + (1 - t) * Xumo::NMath.log(1 - @x))
end

#to_hash ⇒ Object 



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# File 'lib/dnn/core/losses.rb', line 168

def to_hash
  super(eps: @eps)
end