99 lines
3.8 KiB
Python
99 lines
3.8 KiB
Python
import numpy as np
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class LambdaWarmUpCosineScheduler:
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"""
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note: use with a base_lr of 1.0
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"""
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def __init__(self, warm_up_steps, lr_min, lr_max, lr_start, max_decay_steps, verbosity_interval=0):
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self.lr_warm_up_steps = warm_up_steps
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self.lr_start = lr_start
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self.lr_min = lr_min
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self.lr_max = lr_max
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self.lr_max_decay_steps = max_decay_steps
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self.last_lr = 0.
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self.verbosity_interval = verbosity_interval
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def schedule(self, n, **kwargs):
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if self.verbosity_interval > 0:
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if n % self.verbosity_interval == 0: print(f"current step: {n}, recent lr-multiplier: {self.last_lr}")
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if n < self.lr_warm_up_steps:
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lr = (self.lr_max - self.lr_start) / self.lr_warm_up_steps * n + self.lr_start
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self.last_lr = lr
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return lr
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else:
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t = (n - self.lr_warm_up_steps) / (self.lr_max_decay_steps - self.lr_warm_up_steps)
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t = min(t, 1.0)
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lr = self.lr_min + 0.5 * (self.lr_max - self.lr_min) * (
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1 + np.cos(t * np.pi))
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self.last_lr = lr
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return lr
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def __call__(self, n, **kwargs):
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return self.schedule(n,**kwargs)
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class LambdaWarmUpCosineScheduler2:
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"""
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supports repeated iterations, configurable via lists
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note: use with a base_lr of 1.0.
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"""
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def __init__(self, warm_up_steps, f_min, f_max, f_start, cycle_lengths, verbosity_interval=0):
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assert len(warm_up_steps) == len(f_min) == len(f_max) == len(f_start) == len(cycle_lengths)
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self.lr_warm_up_steps = warm_up_steps
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self.f_start = f_start
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self.f_min = f_min
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self.f_max = f_max
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self.cycle_lengths = cycle_lengths
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self.cum_cycles = np.cumsum([0] + list(self.cycle_lengths))
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self.last_f = 0.
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self.verbosity_interval = verbosity_interval
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def find_in_interval(self, n):
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interval = 0
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for cl in self.cum_cycles[1:]:
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if n <= cl:
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return interval
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interval += 1
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def schedule(self, n, **kwargs):
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cycle = self.find_in_interval(n)
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n = n - self.cum_cycles[cycle]
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if self.verbosity_interval > 0:
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if n % self.verbosity_interval == 0: print(f"current step: {n}, recent lr-multiplier: {self.last_f}, "
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f"current cycle {cycle}")
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if n < self.lr_warm_up_steps[cycle]:
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f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle]
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self.last_f = f
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return f
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else:
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t = (n - self.lr_warm_up_steps[cycle]) / (self.cycle_lengths[cycle] - self.lr_warm_up_steps[cycle])
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t = min(t, 1.0)
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f = self.f_min[cycle] + 0.5 * (self.f_max[cycle] - self.f_min[cycle]) * (
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1 + np.cos(t * np.pi))
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self.last_f = f
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return f
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def __call__(self, n, **kwargs):
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return self.schedule(n, **kwargs)
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class LambdaLinearScheduler(LambdaWarmUpCosineScheduler2):
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def schedule(self, n, **kwargs):
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cycle = self.find_in_interval(n)
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n = n - self.cum_cycles[cycle]
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if self.verbosity_interval > 0:
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if n % self.verbosity_interval == 0: print(f"current step: {n}, recent lr-multiplier: {self.last_f}, "
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f"current cycle {cycle}")
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if n < self.lr_warm_up_steps[cycle]:
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f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle]
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self.last_f = f
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return f
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else:
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f = self.f_min[cycle] + (self.f_max[cycle] - self.f_min[cycle]) * (self.cycle_lengths[cycle] - n) / (self.cycle_lengths[cycle])
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self.last_f = f
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return f
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