""" Optimizer Factory w/ Custom Weight Decay
Hacked together by / Copyright 2021 Ross Wightman
"""
from typing import Optional
import torch
import torch.nn as nn
import torch.optim as optim
from .adabelief import AdaBelief
from .adafactor import Adafactor
from .adahessian import Adahessian
from .adamp import AdamP
from .lamb import Lamb
from .lars import Lars
from .lookahead import Lookahead
from .madgrad import MADGRAD
from .nadam import Nadam
from .nvnovograd import NvNovoGrad
from .radam import RAdam
from .rmsprop_tf import RMSpropTF
from .sgdp import SGDP
try:
from apex.optimizers import FusedNovoGrad, FusedAdam, FusedLAMB, FusedSGD
has_apex = True
except ImportError:
has_apex = False
def add_weight_decay(model, weight_decay=1e-5, skip_list=()):
decay = []
no_decay = []
for name, param in model.named_parameters():
if not param.requires_grad:
continue # frozen weights
if len(param.shape) == 1 or name.endswith(".bias") or name in skip_list:
no_decay.append(param)
else:
decay.append(param)
return [
{'params': no_decay, 'weight_decay': 0.},
{'params': decay, 'weight_decay': weight_decay}]
def optimizer_kwargs(cfg):
""" cfg/argparse to kwargs helper
Convert optimizer args in argparse args or cfg like object to keyword args for updated create fn.
"""
kwargs = dict(
opt=cfg.opt,
lr=cfg.lr,
weight_decay=cfg.weight_decay,
momentum=cfg.momentum)
if getattr(cfg, 'opt_eps', None) is not None:
kwargs['eps'] = cfg.opt_eps
if getattr(cfg, 'opt_betas', None) is not None:
kwargs['betas'] = cfg.opt_betas
if getattr(cfg, 'opt_args', None) is not None:
kwargs.update(cfg.opt_args)
return kwargs
def create_optimizer(args, model, filter_bias_and_bn=True):
""" Legacy optimizer factory for backwards compatibility.
NOTE: Use create_optimizer_v2 for new code.
"""
return create_optimizer_v2(
model,
**optimizer_kwargs(cfg=args),
filter_bias_and_bn=filter_bias_and_bn,
)
def create_optimizer_v2(
model_or_params,
opt: str = 'sgd',
lr: Optional[float] = None,
weight_decay: float = 0.,
momentum: float = 0.9,
filter_bias_and_bn: bool = True,
**kwargs):
""" Create an optimizer.
TODO currently the model is passed in and all parameters are selected for optimization.
For more general use an interface that allows selection of parameters to optimize and lr groups, one of:
* a filter fn interface that further breaks params into groups in a weight_decay compatible fashion
* expose the parameters interface and leave it up to caller
Args:
model_or_params (nn.Module): model containing parameters to optimize
opt: name of optimizer to create
lr: initial learning rate
weight_decay: weight decay to apply in optimizer
momentum: momentum for momentum based optimizers (others may use betas via kwargs)
filter_bias_and_bn: filter out bias, bn and other 1d params from weight decay
**kwargs: extra optimizer specific kwargs to pass through
Returns:
Optimizer
"""
if isinstance(model_or_params, nn.Module):
# a model was passed in, extract parameters and add weight decays to appropriate layers
if weight_decay and filter_bias_and_bn:
skip = {}
if hasattr(model_or_params, 'no_weight_decay'):
skip = model_or_params.no_weight_decay()
parameters = add_weight_decay(model_or_params, weight_decay, skip)
weight_decay = 0.
else:
parameters = model_or_params.parameters()
else:
# iterable of parameters or param groups passed in
parameters = model_or_params
opt_lower = opt.lower()
opt_split = opt_lower.split('_')
opt_lower = opt_split[-1]
if 'fused' in opt_lower:
assert has_apex and torch.cuda.is_available(), 'APEX and CUDA required for fused optimizers'
opt_args = dict(weight_decay=weight_decay, **kwargs)
if lr is not None:
opt_args.setdefault('lr', lr)
# basic SGD & related
if opt_lower == 'sgd' or opt_lower == 'nesterov':
# NOTE 'sgd' refers to SGD + nesterov momentum for legacy / backwards compat reasons
opt_args.pop('eps', None)
optimizer = optim.SGD(parameters, momentum=momentum, nesterov=True, **opt_args)
elif opt_lower == 'momentum':
opt_args.pop('eps', None)
optimizer = optim.SGD(parameters, momentum=momentum, nesterov=False, **opt_args)
elif opt_lower == 'sgdp':
optimizer = SGDP(parameters, momentum=momentum, nesterov=True, **opt_args)
# adaptive
elif opt_lower == 'adam':
optimizer = optim.Adam(parameters, **opt_args)
elif opt_lower == 'adamw':
optimizer = optim.AdamW(parameters, **opt_args)
elif opt_lower == 'adamp':
optimizer = AdamP(parameters, wd_ratio=0.01, nesterov=True, **opt_args)
elif opt_lower == 'nadam':
try:
# NOTE PyTorch >= 1.10 should have native NAdam
optimizer = optim.Nadam(parameters, **opt_args)
except AttributeError:
optimizer = Nadam(parameters, **opt_args)
elif opt_lower == 'radam':
optimizer = RAdam(parameters, **opt_args)
elif opt_lower == 'adamax':
optimizer = optim.Adamax(parameters, **opt_args)
elif opt_lower == 'adabelief':
optimizer = AdaBelief(parameters, rectify=False, **opt_args)
elif opt_lower == 'radabelief':
optimizer = AdaBelief(parameters, rectify=True, **opt_args)
elif opt_lower == 'adadelta':
optimizer = optim.Adadelta(parameters, **opt_args)
elif opt_lower == 'adagrad':
opt_args.setdefault('eps', 1e-8)
optimizer = optim.Adagrad(parameters, **opt_args)
elif opt_lower == 'adafactor':
optimizer = Adafactor(parameters, **opt_args)
elif opt_lower == 'lamb':
optimizer = Lamb(parameters, **opt_args)
elif opt_lower == 'lambc':
optimizer = Lamb(parameters, trust_clip=True, **opt_args)
elif opt_lower == 'larc':
optimizer = Lars(parameters, momentum=momentum, trust_clip=True, **opt_args)
elif opt_lower == 'lars':
optimizer = Lars(parameters, momentum=momentum, **opt_args)
elif opt_lower == 'nlarc':
optimizer = Lars(parameters, momentum=momentum, trust_clip=True, nesterov=True, **opt_args)
elif opt_lower == 'nlars':
optimizer = Lars(parameters, momentum=momentum, nesterov=True, **opt_args)
elif opt_lower == 'madgrad':
optimizer = MADGRAD(parameters, momentum=momentum, **opt_args)
elif opt_lower == 'madgradw':
optimizer = MADGRAD(parameters, momentum=momentum, decoupled_decay=True, **opt_args)
elif opt_lower == 'novograd' or opt_lower == 'nvnovograd':
optimizer = NvNovoGrad(parameters, **opt_args)
elif opt_lower == 'rmsprop':
optimizer = optim.RMSprop(parameters, alpha=0.9, momentum=momentum, **opt_args)
elif opt_lower == 'rmsproptf':
optimizer = RMSpropTF(parameters, alpha=0.9, momentum=momentum, **opt_args)
# second order
elif opt_lower == 'adahessian':
optimizer = Adahessian(parameters, **opt_args)
# NVIDIA fused optimizers, require APEX to be installed
elif opt_lower == 'fusedsgd':
opt_args.pop('eps', None)
optimizer = FusedSGD(parameters, momentum=momentum, nesterov=True, **opt_args)
elif opt_lower == 'fusedmomentum':
opt_args.pop('eps', None)
optimizer = FusedSGD(parameters, momentum=momentum, nesterov=False, **opt_args)
elif opt_lower == 'fusedadam':
optimizer = FusedAdam(parameters, adam_w_mode=False, **opt_args)
elif opt_lower == 'fusedadamw':
optimizer = FusedAdam(parameters, adam_w_mode=True, **opt_args)
elif opt_lower == 'fusedlamb':
optimizer = FusedLAMB(parameters, **opt_args)
elif opt_lower == 'fusednovograd':
opt_args.setdefault('betas', (0.95, 0.98))
optimizer = FusedNovoGrad(parameters, **opt_args)
else:
assert False and "Invalid optimizer"
raise ValueError
if len(opt_split) > 1:
if opt_split[0] == 'lookahead':
optimizer = Lookahead(optimizer)
return optimizer