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Sleeping
import numpy as np | |
import math | |
class LearningRateDecay: | |
def __init__(self, lr=0.002, warmup_steps=4000.0) -> None: | |
self.lr = lr | |
self.warmup_steps = warmup_steps | |
def __call__(self, global_step) -> float: | |
step = global_step + 1.0 | |
lr = ( | |
self.lr | |
* self.warmup_steps ** 0.5 | |
* np.minimum(step * self.warmup_steps ** -1.5, step ** -0.5) | |
) | |
return lr | |
class SquareRootScheduler: | |
def __init__(self, lr=0.1): | |
self.lr = lr | |
def __call__(self, global_step): | |
global_step = global_step // 1000 | |
return self.lr * pow(global_step + 1.0, -0.5) | |
class CosineScheduler: | |
def __init__( | |
self, max_update, base_lr=0.02, final_lr=0, warmup_steps=0, warmup_begin_lr=0 | |
): | |
self.base_lr_orig = base_lr | |
self.max_update = max_update | |
self.final_lr = final_lr | |
self.warmup_steps = warmup_steps | |
self.warmup_begin_lr = warmup_begin_lr | |
self.max_steps = self.max_update - self.warmup_steps | |
def get_warmup_lr(self, global_step): | |
increase = ( | |
(self.base_lr_orig - self.warmup_begin_lr) | |
* float(global_step) | |
/ float(self.warmup_steps) | |
) | |
return self.warmup_begin_lr + increase | |
def __call__(self, global_step): | |
if global_step < self.warmup_steps: | |
return self.get_warmup_lr(global_step) | |
if global_step <= self.max_update: | |
self.base_lr = ( | |
self.final_lr | |
+ (self.base_lr_orig - self.final_lr) | |
* ( | |
1 | |
+ math.cos( | |
math.pi * (global_step - self.warmup_steps) / self.max_steps | |
) | |
) | |
/ 2 | |
) | |
return self.base_lr | |
def adjust_learning_rate(optimizer, global_step): | |
lr = LearningRateDecay()(global_step=global_step) | |
for param_group in optimizer.param_groups: | |
param_group["lr"] = lr | |
return lr | |