Xingqian Xu
New app first commit
2fbcf51
import torch
import torch.optim as optim
import numpy as np
import copy
from ... import sync
from ...cfg_holder import cfg_unique_holder as cfguh
def singleton(class_):
instances = {}
def getinstance(*args, **kwargs):
if class_ not in instances:
instances[class_] = class_(*args, **kwargs)
return instances[class_]
return getinstance
@singleton
class get_scheduler(object):
def __init__(self):
self.lr_scheduler = {}
def register(self, lrsf, name):
self.lr_scheduler[name] = lrsf
def __call__(self, cfg):
if cfg is None:
return None
if isinstance(cfg, list):
schedulers = []
for ci in cfg:
t = ci.type
schedulers.append(
self.lr_scheduler[t](**ci.args))
if len(schedulers) == 0:
raise ValueError
else:
return compose_scheduler(schedulers)
t = cfg.type
return self.lr_scheduler[t](**cfg.args)
def register(name):
def wrapper(class_):
get_scheduler().register(class_, name)
return class_
return wrapper
class template_scheduler(object):
def __init__(self, step):
self.step = step
def __getitem__(self, idx):
raise ValueError
def set_lr(self, optim, new_lr, pg_lrscale=None):
"""
Set Each parameter_groups in optim with new_lr
New_lr can be find according to the idx.
pg_lrscale tells how to scale each pg.
"""
# new_lr = self.__getitem__(idx)
pg_lrscale = copy.deepcopy(pg_lrscale)
for pg in optim.param_groups:
if pg_lrscale is None:
pg['lr'] = new_lr
else:
pg['lr'] = new_lr * pg_lrscale.pop(pg['name'])
assert (pg_lrscale is None) or (len(pg_lrscale)==0), \
"pg_lrscale doesn't match pg"
@register('constant')
class constant_scheduler(template_scheduler):
def __init__(self, lr, step):
super().__init__(step)
self.lr = lr
def __getitem__(self, idx):
if idx >= self.step:
raise ValueError
return self.lr
@register('poly')
class poly_scheduler(template_scheduler):
def __init__(self, start_lr, end_lr, power, step):
super().__init__(step)
self.start_lr = start_lr
self.end_lr = end_lr
self.power = power
def __getitem__(self, idx):
if idx >= self.step:
raise ValueError
a, b = self.start_lr, self.end_lr
p, n = self.power, self.step
return b + (a-b)*((1-idx/n)**p)
@register('linear')
class linear_scheduler(template_scheduler):
def __init__(self, start_lr, end_lr, step):
super().__init__(step)
self.start_lr = start_lr
self.end_lr = end_lr
def __getitem__(self, idx):
if idx >= self.step:
raise ValueError
a, b, n = self.start_lr, self.end_lr, self.step
return b + (a-b)*(1-idx/n)
@register('multistage')
class constant_scheduler(template_scheduler):
def __init__(self, start_lr, milestones, gamma, step):
super().__init__(step)
self.start_lr = start_lr
m = [0] + milestones + [step]
lr_iter = start_lr
self.lr = []
for ms, me in zip(m[0:-1], m[1:]):
for _ in range(ms, me):
self.lr.append(lr_iter)
lr_iter *= gamma
def __getitem__(self, idx):
if idx >= self.step:
raise ValueError
return self.lr[idx]
class compose_scheduler(template_scheduler):
def __init__(self, schedulers):
self.schedulers = schedulers
self.step = [si.step for si in schedulers]
self.step_milestone = []
acc = 0
for i in self.step:
acc += i
self.step_milestone.append(acc)
self.step = sum(self.step)
def __getitem__(self, idx):
if idx >= self.step:
raise ValueError
ms = self.step_milestone
for idx, (mi, mj) in enumerate(zip(ms[:-1], ms[1:])):
if mi <= idx < mj:
return self.schedulers[idx-mi]
raise ValueError
####################
# lambda schedular #
####################
class LambdaWarmUpCosineScheduler(template_scheduler):
"""
note: use with a base_lr of 1.0
"""
def __init__(self,
base_lr,
warm_up_steps,
lr_min, lr_max, lr_start, max_decay_steps, verbosity_interval=0):
cfgt = cfguh().cfg.train
bs = cfgt.batch_size
if 'gradacc_every' not in cfgt:
print('Warning, gradacc_every is not found in xml, use 1 as default.')
acc = cfgt.get('gradacc_every', 1)
self.lr_multi = base_lr * bs * acc
self.lr_warm_up_steps = warm_up_steps
self.lr_start = lr_start
self.lr_min = lr_min
self.lr_max = lr_max
self.lr_max_decay_steps = max_decay_steps
self.last_lr = 0.
self.verbosity_interval = verbosity_interval
def schedule(self, n):
if self.verbosity_interval > 0:
if n % self.verbosity_interval == 0:
print(f"current step: {n}, recent lr-multiplier: {self.last_lr}")
if n < self.lr_warm_up_steps:
lr = (self.lr_max - self.lr_start) / self.lr_warm_up_steps * n + self.lr_start
self.last_lr = lr
return lr
else:
t = (n - self.lr_warm_up_steps) / (self.lr_max_decay_steps - self.lr_warm_up_steps)
t = min(t, 1.0)
lr = self.lr_min + 0.5 * (self.lr_max - self.lr_min) * (
1 + np.cos(t * np.pi))
self.last_lr = lr
return lr
def __getitem__(self, idx):
return self.schedule(idx) * self.lr_multi
class LambdaWarmUpCosineScheduler2(template_scheduler):
"""
supports repeated iterations, configurable via lists
note: use with a base_lr of 1.0.
"""
def __init__(self,
base_lr,
warm_up_steps,
f_min, f_max, f_start, cycle_lengths, verbosity_interval=0):
cfgt = cfguh().cfg.train
# bs = cfgt.batch_size
# if 'gradacc_every' not in cfgt:
# print('Warning, gradacc_every is not found in xml, use 1 as default.')
# acc = cfgt.get('gradacc_every', 1)
# self.lr_multi = base_lr * bs * acc
self.lr_multi = base_lr
assert len(warm_up_steps) == len(f_min) == len(f_max) == len(f_start) == len(cycle_lengths)
self.lr_warm_up_steps = warm_up_steps
self.f_start = f_start
self.f_min = f_min
self.f_max = f_max
self.cycle_lengths = cycle_lengths
self.cum_cycles = np.cumsum([0] + list(self.cycle_lengths))
self.last_f = 0.
self.verbosity_interval = verbosity_interval
def find_in_interval(self, n):
interval = 0
for cl in self.cum_cycles[1:]:
if n <= cl:
return interval
interval += 1
def schedule(self, n):
cycle = self.find_in_interval(n)
n = n - self.cum_cycles[cycle]
if self.verbosity_interval > 0:
if n % self.verbosity_interval == 0: print(f"current step: {n}, recent lr-multiplier: {self.last_f}, "
f"current cycle {cycle}")
if n < self.lr_warm_up_steps[cycle]:
f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle]
self.last_f = f
return f
else:
t = (n - self.lr_warm_up_steps[cycle]) / (self.cycle_lengths[cycle] - self.lr_warm_up_steps[cycle])
t = min(t, 1.0)
f = self.f_min[cycle] + 0.5 * (self.f_max[cycle] - self.f_min[cycle]) * (
1 + np.cos(t * np.pi))
self.last_f = f
return f
def __getitem__(self, idx):
return self.schedule(idx) * self.lr_multi
@register('stable_diffusion_linear')
class LambdaLinearScheduler(LambdaWarmUpCosineScheduler2):
def schedule(self, n):
cycle = self.find_in_interval(n)
n = n - self.cum_cycles[cycle]
if self.verbosity_interval > 0:
if n % self.verbosity_interval == 0:
print(f"current step: {n}, recent lr-multiplier: {self.last_f}, "
f"current cycle {cycle}")
if n < self.lr_warm_up_steps[cycle]:
f = (self.f_max[cycle] - self.f_start[cycle]) / self.lr_warm_up_steps[cycle] * n + self.f_start[cycle]
self.last_f = f
return f
else:
f = self.f_min[cycle] + (self.f_max[cycle] - self.f_min[cycle]) * (self.cycle_lengths[cycle] - n) / (self.cycle_lengths[cycle])
self.last_f = f
return f