from utils.hparams import hparams
class RSQRTSchedule(object):
def __init__(self, optimizer):
super().__init__()
self.optimizer = optimizer
self.constant_lr = hparams['lr']
self.warmup_updates = hparams['warmup_updates']
self.hidden_size = hparams['hidden_size']
self.lr = hparams['lr']
for param_group in optimizer.param_groups:
param_group['lr'] = self.lr
self.step(0)
def step(self, num_updates):
constant_lr = self.constant_lr
warmup = min(num_updates / self.warmup_updates, 1.0)
rsqrt_decay = max(self.warmup_updates, num_updates) ** -0.5
rsqrt_hidden = self.hidden_size ** -0.5
self.lr = max(constant_lr * warmup * rsqrt_decay * rsqrt_hidden, 1e-7)
for param_group in self.optimizer.param_groups:
param_group['lr'] = self.lr
return self.lr
def get_lr(self):
return self.optimizer.param_groups[0]['lr']
