optim_factory.py

# ------------------------------------------------------------
# Copyright (c) VCU, Nanjing University.
# Licensed under the Apache License 2.0 [see LICENSE for details]
# Written by Qing-Long Zhang
# ------------------------------------------------------------

import torch
from torch import optim as optim

from timm.optim.adafactor import Adafactor
from timm.optim.adahessian import Adahessian
from timm.optim.adamp import AdamP
from timm.optim.lookahead import Lookahead
from timm.optim.nadam import Nadam
from timm.optim.nvnovograd import NvNovoGrad
from timm.optim.radam import RAdam
from timm.optim.rmsprop_tf import RMSpropTF
from timm.optim.sgdp import SGDP
from timm.optim.lamb import Lamb
from timm.optim.lars import Lars

import json

try:
    from apex.optimizers import FusedNovoGrad, FusedAdam, FusedLAMB, FusedSGD

    has_apex = True
except ImportError:
    has_apex = False


def get_layer_id_for_rest(model, name):
    """
    Assign a parameter with its layer id
    Following BEiT: https://github.com/microsoft/unilm/blob/master/beit/optim_factory.py#L33
    """
    depths = model.depths
    if name in ['cls_token', 'pos_embed']:
        return 0
    elif name.startswith('stem'):
        return 0
    elif name.startswith('patch'):
        layer_id = int(name.split('.')[0].split('_')[1])
        if layer_id == 2:
            layer_id = depths[0] + 1
        elif layer_id == 3:
            layer_id = sum(depths[:2]) + 2
        else:
            layer_id = sum(depths[:3]) + 3
        return int(layer_id)
    elif name.startswith('stage'):
        stage_id = int(name.split('.')[0][-1])
        layer_id = int(name.split('.')[1])
        if stage_id == 1:
            layer_id = layer_id + 1
        elif stage_id == 2:
            layer_id = depths[0] + layer_id + 2
        elif stage_id == 3:
            layer_id = sum(depths[:2]) + layer_id + 3
        else:
            layer_id = sum(depths[:3]) + layer_id + 4
        return int(layer_id)
    else:
        return sum(depths) + 4


class LayerDecayValueAssigner(object):
    def __init__(self, values):
        self.values = values

    def get_scale(self, layer_id):
        return self.values[layer_id]

    def get_layer_id(self, model, var_name):
        return get_layer_id_for_rest(model, var_name)


def get_parameter_groups(model, weight_decay=1e-5, skip_list=(), get_num_layer=None, get_layer_scale=None):
    parameter_group_names = {}
    parameter_group_vars = {}

    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:
            group_name = "no_decay"
            this_weight_decay = 0.
        else:
            group_name = "decay"
            this_weight_decay = weight_decay
        if get_num_layer is not None:
            layer_id = get_num_layer(model, name)
            print("layer_id: {}", layer_id)
            group_name = "layer_%d_%s" % (layer_id, group_name)
        else:
            layer_id = None

        if group_name not in parameter_group_names:
            if get_layer_scale is not None:
                scale = get_layer_scale(layer_id)
            else:
                scale = 1.

            parameter_group_names[group_name] = {
                "weight_decay": this_weight_decay,
                "params": [],
                "lr_scale": scale
            }
            parameter_group_vars[group_name] = {
                "weight_decay": this_weight_decay,
                "params": [],
                "lr_scale": scale
            }

        parameter_group_vars[group_name]["params"].append(param)
        parameter_group_names[group_name]["params"].append(name)
    print("Param groups = %s" % json.dumps(parameter_group_names, indent=2))
    return list(parameter_group_vars.values())


def create_optimizer(args, model, get_num_layer=None, get_layer_scale=None, filter_bias_and_bn=True, skip_list=None):
    opt_lower = args.opt.lower()
    weight_decay = args.weight_decay
    # if weight_decay and filter_bias_and_bn:
    if filter_bias_and_bn:
        skip = {}
        if skip_list is not None:
            skip = skip_list
        elif hasattr(model, 'no_weight_decay'):
            skip = model.no_weight_decay()
        parameters = get_parameter_groups(model, weight_decay, skip, get_num_layer, get_layer_scale)
        weight_decay = 0.
    else:
        parameters = model.parameters()

    if 'fused' in opt_lower:
        assert has_apex and torch.cuda.is_available(), 'APEX and CUDA required for fused optimizers'

    opt_args = dict(lr=args.lr, weight_decay=weight_decay)
    if hasattr(args, 'opt_eps') and args.opt_eps is not None:
        opt_args['eps'] = args.opt_eps
    if hasattr(args, 'opt_betas') and args.opt_betas is not None:
        opt_args['betas'] = args.opt_betas

    opt_split = opt_lower.split('_')
    opt_lower = opt_split[-1]
    if opt_lower == 'sgd' or opt_lower == 'nesterov':
        opt_args.pop('eps', None)
        optimizer = optim.SGD(parameters, momentum=args.momentum, nesterov=True, **opt_args)
    elif opt_lower == 'momentum':
        opt_args.pop('eps', None)
        optimizer = optim.SGD(parameters, momentum=args.momentum, nesterov=False, **opt_args)
    elif opt_lower == 'adam':
        optimizer = optim.Adam(parameters, **opt_args)
    elif opt_lower == 'adamw':
        optimizer = optim.AdamW(parameters, **opt_args)
    elif opt_lower == 'nadam':
        optimizer = Nadam(parameters, **opt_args)
    elif opt_lower == 'radam':
        optimizer = RAdam(parameters, **opt_args)
    elif opt_lower == 'adamp':
        optimizer = AdamP(parameters, wd_ratio=0.01, nesterov=True, **opt_args)
    elif opt_lower == 'sgdp':
        optimizer = SGDP(parameters, momentum=args.momentum, nesterov=True, **opt_args)
    elif opt_lower == 'adadelta':
        optimizer = optim.Adadelta(parameters, **opt_args)
    elif opt_lower == 'adafactor':
        if not args.lr:
            opt_args['lr'] = None
        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 == 'lars':
        optimizer = Lars(parameters, momentum=args.momentum, **opt_args)
    elif opt_lower == 'adahessian':
        optimizer = Adahessian(parameters, **opt_args)
    elif opt_lower == 'rmsprop':
        optimizer = optim.RMSprop(parameters, alpha=0.9, momentum=args.momentum, **opt_args)
    elif opt_lower == 'rmsproptf':
        optimizer = RMSpropTF(parameters, alpha=0.9, momentum=args.momentum, **opt_args)
    elif opt_lower == 'nvnovograd':
        optimizer = NvNovoGrad(parameters, **opt_args)
    elif opt_lower == 'fusedsgd':
        opt_args.pop('eps', None)
        optimizer = FusedSGD(parameters, momentum=args.momentum, nesterov=True, **opt_args)
    elif opt_lower == 'fusedmomentum':
        opt_args.pop('eps', None)
        optimizer = FusedSGD(parameters, momentum=args.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"

    if len(opt_split) > 1:
        if opt_split[0] == 'lookahead':
            optimizer = Lookahead(optimizer)

    return optimizer