Class: Torch::Optim::Adagrad

Inherits:
Optimizer show all
Defined in:
lib/torch/optim/adagrad.rb

Instance Attribute Summary

Attributes inherited from Optimizer

#param_groups

Instance Method Summary collapse

Methods inherited from Optimizer

#add_param_group, #load_state_dict, #state_dict, #zero_grad

Constructor Details

#initialize(params, lr: 1e-2, lr_decay: 0, weight_decay: 0, initial_accumulator_value: 0, eps: 1e-10) ⇒ Adagrad

Returns a new instance of Adagrad.

Raises:

  • (ArgumentError) 


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# File 'lib/torch/optim/adagrad.rb', line 5

def initialize(params, lr: 1e-2, lr_decay: 0, weight_decay: 0, initial_accumulator_value: 0, eps: 1e-10)
  raise ArgumentError, "Invalid learning rate: #{lr}" if lr < 0
  raise ArgumentError, "Invalid lr_decay value: #{lr_decay}" if lr_decay < 0
  raise ArgumentError, "Invalid initial_accumulator_value value: #{initial_accumulator_value}" if initial_accumulator_value < 0
  raise ArgumentError, "Invalid weight_decay value: #{weight_decay}" if weight_decay < 0
  raise ArgumentError, "Invalid epsilon value: #{eps}" if eps < 0

  defaults = {lr: lr, lr_decay: lr_decay, eps: eps, weight_decay: weight_decay, initial_accumulator_value: initial_accumulator_value}
  super(params, defaults)

  @param_groups.each do |group|
    group[:params].each do |p|
      state = @state[p]
      state[:step] = 0
      state[:sum] = Torch.full_like(p.data, initial_accumulator_value)
    end
  end
end

Instance Method Details

#share_memory ⇒ Object 



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# File 'lib/torch/optim/adagrad.rb', line 24

def share_memory
  @param_groups.each do |group|
    group[:params].each do |p|
      state = @state[p]
      state[:sum].share_memory!
    end
  end
end

#step(closure = nil) ⇒ Object 



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# File 'lib/torch/optim/adagrad.rb', line 33

def step(closure = nil)
  loss = nil
  if closure
    loss = closure.call
  end

  @param_groups.each do |group|
    group[:params].each do |p|
      next unless p.grad

      grad = p.grad.data
      state = @state[p]

      state[:step] += 1

      if group[:weight_decay] != 0
        if p.grad.data.sparse?
          raise Error, "weight_decay option is not compatible with sparse gradients"
        end
        grad = grad.add(p.data, alpha: group[:weight_decay])
      end

      clr = group[:lr] / (1 + (state[:step] - 1) * group[:lr_decay])

      if grad.sparse?
        raise NotImplementedYet
      else
        state[:sum].addcmul!(grad, grad, value: 1)
        std = state[:sum].sqrt.add!(group[:eps])
        p.data.addcdiv!(grad, std, value: -clr)
      end
    end
  end

  loss
end