Class: DNN::Optimizers::SGD

Inherits:
Optimizer show all
Defined in:
lib/dnn/core/optimizers.rb

Instance Attribute Summary collapse

Attributes inherited from Optimizer

#learning_rate

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(learning_rate = 0.01, momentum: 0) ⇒ SGD

Returns a new instance of SGD.



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# File 'lib/dnn/core/optimizers.rb', line 24

def initialize(learning_rate = 0.01, momentum: 0)
  super(learning_rate)
  @momentum = momentum
  @amounts = {}
end

Instance Attribute Details

#momentum ⇒ Object

Returns the value of attribute momentum.



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# File 'lib/dnn/core/optimizers.rb', line 22

def momentum
  @momentum
end

Class Method Details

.load_hash(hash) ⇒ Object 



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# File 'lib/dnn/core/optimizers.rb', line 30

def self.load_hash(hash)
  self.new(hash[:learning_rate], hash[:momentum])
end

Instance Method Details

#to_hash ⇒ Object 



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# File 'lib/dnn/core/optimizers.rb', line 51

def to_hash
  {
    name: self.class.name,
    learning_rate: @learning_rate,
    momentum: @momentum,
  }
end

#update(layer) ⇒ Object 



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# File 'lib/dnn/core/optimizers.rb', line 34

def update(layer)
  amount = if @amounts[layer]
    @amounts[layer]
  else
    @amounts[layer] = {}
  end
  layer.params.each_key do |key|
    amount[key] = layer.grads[key] * @learning_rate
    if @momentum > 0
      @amounts[layer][key] ||= 0
      amount[key] += @momentum * @amounts[layer][key]
      @amounts[layer] = amount
    end
    layer.params[key] -= amount[key]
  end
end