Class: DNN::Optimizers::SGD

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

Direct Known Subclasses

Nesterov

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 33

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

Instance Attribute Details

#momentum ⇒ Object

Returns the value of attribute momentum.



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# File 'lib/dnn/core/optimizers.rb', line 27

def momentum
  @momentum
end

Class Method Details

.load_hash(hash) ⇒ Object 



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# File 'lib/dnn/core/optimizers.rb', line 29

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

Instance Method Details

#to_hash ⇒ Object 



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

def to_hash
  super({momentum: @momentum})
end

#update(params) ⇒ Object 



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# File 'lib/dnn/core/optimizers.rb', line 39

def update(params)
  params.select { |key, param| param.grad }.each_value do |param|
    amount = param.grad * @learning_rate
    if @momentum > 0
      @v[param] ||= 0
      amount += @momentum * @v[param]
      @v[param] = amount
    end
    param.data -= amount
  end
end