Class: Torch::Optim::LRScheduler::CosineAnnealingLR

Inherits:
LRScheduler
  • Object
show all
Defined in:
lib/torch/optim/lr_scheduler/cosine_annealing_lr.rb

Instance Method Summary collapse

Methods inherited from LRScheduler

#step

Constructor Details

#initialize(optimizer, t_max, eta_min: 0, last_epoch: -1)) ⇒ CosineAnnealingLR

Returns a new instance of CosineAnnealingLR.



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

def initialize(optimizer, t_max, eta_min: 0, last_epoch: -1)
  @t_max = t_max
  @eta_min = eta_min
  super(optimizer, last_epoch)
end

Instance Method Details

#get_lr ⇒ Object 



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# File 'lib/torch/optim/lr_scheduler/cosine_annealing_lr.rb', line 11

def get_lr
  if @last_epoch == 0
    @base_lrs
  elsif (@last_epoch - 1 - @t_max) % (2 * @t_max) == 0
    @base_lrs.zip(@optimizer.param_groups).map do |base_lr, group|
      group[:lr] + (base_lr - @eta_min) * (1 - Math.cos(Math::PI / @t_max)) / 2
    end
  else
    @optimizer.param_groups.map do |group|
      (1 + Math.cos(Math::PI * @last_epoch / @t_max)) /
      (1 + Math.cos(Math::PI * (@last_epoch - 1) / @t_max)) *
      (group[:lr] - @eta_min) + @eta_min
    end
  end
end