Class: NN::Softmax

Inherits:
Object
  • Object
show all
Includes:
Numo
Defined in:
lib/nn.rb

Instance Method Summary collapse

Constructor Details

#initialize(nn) ⇒ Softmax

Returns a new instance of Softmax.



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# File 'lib/nn.rb', line 362

def initialize(nn)
  @nn = nn
end

Instance Method Details

#backward(y) ⇒ Object 



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# File 'lib/nn.rb', line 370

def backward(y)
  (@out - y) / @nn.batch_size
end

#forward(x) ⇒ Object 



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# File 'lib/nn.rb', line 366

def forward(x)
  @out = NMath.exp(x) / NMath.exp(x).sum(1).reshape(x.shape[0], 1)
end

#loss(y) ⇒ Object 



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# File 'lib/nn.rb', line 374

def loss(y)
  ridge = 0.5 * @nn.weight_decay * @nn.weights.reduce(0){|sum, weight| sum + (weight ** 2).sum}
  -(y * NMath.log(@out + 1e-7)).sum / @nn.batch_size + ridge
end