Class: DNN::Layers::Embedding

Inherits:
HasParamLayer show all
Defined in:
lib/dnn/core/embedding.rb

Instance Attribute Summary collapse

Attributes inherited from HasParamLayer

#params, #trainable

Attributes inherited from Layer

#input_shape, #learning_phase

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Layer

#built?, #output_shape

Constructor Details

#initialize(input_dim_or_shape, input_length, weight_initializer: Initializers::RandomUniform.new) ⇒ Embedding

Returns a new instance of Embedding.

Parameters:

  • input_dim_or_shape (Integer | Array) —

    Set input data dimension or shape.

  • input_length (Integer) —

    input Set the time series length of input data.



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# File 'lib/dnn/core/embedding.rb', line 17

def initialize(input_dim_or_shape, input_length, weight_initializer: Initializers::RandomUniform.new)
  super()
  @input_shape = input_dim_or_shape.is_a?(Array) ? input_dim_or_shape : [input_dim_or_shape]
  @input_length = input_length
  @weight_initializer = weight_initializer
end

Instance Attribute Details

#input_length ⇒ Integer (readonly)

Return the input length.

Returns:

  • (Integer) —

    Return the input length.



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# File 'lib/dnn/core/embedding.rb', line 6

def input_length
  @input_length
end

#weight_initializer ⇒ Initializers::Initializer (readonly)

Return the weight initializer.

Returns:



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# File 'lib/dnn/core/embedding.rb', line 8

def weight_initializer
  @weight_initializer
end

Class Method Details

.from_hash(hash) ⇒ Object 



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# File 'lib/dnn/core/embedding.rb', line 10

def self.from_hash(hash)
  self.new(hash[:input_shape], hash[:input_length],
           weight_initializer: DNN::Utils.from_hash(hash[:weight_initializer]))
end

Instance Method Details

#backward(dy) ⇒ Object 



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# File 'lib/dnn/core/embedding.rb', line 40

def backward(dy)
  @weight.grad += Xumo::SFloat.zeros(*@weight.data.shape)
  @x.shape[0].times do |i|
    @x.shape[1].times do |j|
      @weight.grad[@x[i, j]] += dy[i, j]
    end
  end
  nil
end

#build ⇒ Object 



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

def build
  @built = true
  @params[:weight] = @weight = Param.new(Xumo::SFloat.new(@input_length), 0)
  @weight_initializer.init_param(self, @weight)
  @input_shape
end

#forward(x) ⇒ Object 



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# File 'lib/dnn/core/embedding.rb', line 31

def forward(x)
  @x = x
  y = Xumo::SFloat.zeros(*x.shape)
  x.shape[0].times do |i|
    y[i, false] = @weight.data[x[i, false]]
  end
  y
end

#to_hash ⇒ Object 



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# File 'lib/dnn/core/embedding.rb', line 50

def to_hash
  super(input_shape: @input_shape, input_length: @input_length, weight_initializer: @weight_initializer.to_hash)
end