fast-reid/fastreid/solver/build.py

56 lines
1.6 KiB
Python

# encoding: utf-8
"""
@author: liaoxingyu
@contact: sherlockliao01@gmail.com
"""
from . import lr_scheduler
from . import optim
def build_optimizer(cfg, model):
params = []
for key, value in model.named_parameters():
if not value.requires_grad:
continue
lr = cfg.SOLVER.BASE_LR
weight_decay = cfg.SOLVER.WEIGHT_DECAY
if "heads" in key:
lr *= cfg.SOLVER.HEADS_LR_FACTOR
if "bias" in key:
lr *= cfg.SOLVER.BIAS_LR_FACTOR
weight_decay = cfg.SOLVER.WEIGHT_DECAY_BIAS
params += [{"name": key, "params": [value], "lr": lr, "weight_decay": weight_decay, "freeze": False}]
solver_opt = cfg.SOLVER.OPT
if hasattr(optim, solver_opt):
if solver_opt == "SGD":
opt_fns = getattr(optim, solver_opt)(params, momentum=cfg.SOLVER.MOMENTUM)
else:
opt_fns = getattr(optim, solver_opt)(params)
else:
raise NameError("optimizer {} not support".format(cfg.SOLVER.OPT))
return opt_fns
def build_lr_scheduler(cfg, optimizer):
scheduler_args = {
"optimizer": optimizer,
# warmup options
"warmup_factor": cfg.SOLVER.WARMUP_FACTOR,
"warmup_iters": cfg.SOLVER.WARMUP_ITERS,
"warmup_method": cfg.SOLVER.WARMUP_METHOD,
# multi-step lr scheduler options
"milestones": cfg.SOLVER.STEPS,
"gamma": cfg.SOLVER.GAMMA,
# cosine annealing lr scheduler options
"max_iters": cfg.SOLVER.MAX_ITER,
"delay_iters": cfg.SOLVER.DELAY_ITERS,
"eta_min_lr": cfg.SOLVER.ETA_MIN_LR,
}
return getattr(lr_scheduler, cfg.SOLVER.SCHED)(**scheduler_args)