|
| 1 | +import math |
| 2 | + |
| 3 | +import torch |
| 4 | +from torch.optim.optimizer import Optimizer |
| 5 | + |
| 6 | +from pytorch_optimizer.types import ( |
| 7 | + BETAS, |
| 8 | + CLOSURE, |
| 9 | + DEFAULT_PARAMETERS, |
| 10 | + LOSS, |
| 11 | + PARAMS, |
| 12 | + STATE, |
| 13 | +) |
| 14 | + |
| 15 | + |
| 16 | +class AdaBound(Optimizer): |
| 17 | + """ |
| 18 | + Reference : https://github.com/Luolc/AdaBound/blob/master/adabound/adabound.py |
| 19 | + Example : |
| 20 | + from pytorch_optimizer import AdaBound |
| 21 | + ... |
| 22 | + model = YourModel() |
| 23 | + optimizer = AdaBound(model.parameters()) |
| 24 | + ... |
| 25 | + for input, output in data: |
| 26 | + optimizer.zero_grad() |
| 27 | + loss = loss_function(output, model(input)) |
| 28 | + loss.backward() |
| 29 | + optimizer.step() |
| 30 | + """ |
| 31 | + |
| 32 | + def __init__( |
| 33 | + self, |
| 34 | + params: PARAMS, |
| 35 | + lr: float = 1e-3, |
| 36 | + betas: BETAS = (0.9, 0.999), |
| 37 | + final_lr: float = 0.1, |
| 38 | + gamma: float = 1e-3, |
| 39 | + eps: float = 1e-8, |
| 40 | + weight_decay: float = 0.0, |
| 41 | + amsbound: bool = False, |
| 42 | + ): |
| 43 | + """AdaBound optimizer |
| 44 | + :param params: PARAMS. iterable of parameters to optimize or dicts defining parameter groups |
| 45 | + :param lr: float. learning rate |
| 46 | + :param final_lr: float. final learning rate |
| 47 | + :param betas: BETAS. coefficients used for computing running averages of gradient and the squared hessian trace |
| 48 | + :param gamma: float. convergence speed of the bound functions |
| 49 | + :param eps: float. term added to the denominator to improve numerical stability |
| 50 | + :param weight_decay: float. weight decay (L2 penalty) |
| 51 | + :param amsbound: bool. whether to use the AMSBound variant |
| 52 | + """ |
| 53 | + self.lr = lr |
| 54 | + self.betas = betas |
| 55 | + self.eps = eps |
| 56 | + self.weight_decay = weight_decay |
| 57 | + |
| 58 | + defaults: DEFAULT_PARAMETERS = dict( |
| 59 | + lr=lr, |
| 60 | + betas=betas, |
| 61 | + final_lr=final_lr, |
| 62 | + gamma=gamma, |
| 63 | + eps=eps, |
| 64 | + weight_decay=weight_decay, |
| 65 | + amsbound=amsbound, |
| 66 | + ) |
| 67 | + super().__init__(params, defaults) |
| 68 | + |
| 69 | + self.base_lrs = [group['lr'] for group in self.param_groups] |
| 70 | + |
| 71 | + def check_valid_parameters(self): |
| 72 | + if 0.0 > self.lr: |
| 73 | + raise ValueError(f'Invalid learning rate : {self.lr}') |
| 74 | + if 0.0 > self.eps: |
| 75 | + raise ValueError(f'Invalid eps : {self.eps}') |
| 76 | + if 0.0 > self.weight_decay: |
| 77 | + raise ValueError(f'Invalid weight_decay : {self.weight_decay}') |
| 78 | + if not 0.0 <= self.betas[0] < 1.0: |
| 79 | + raise ValueError(f'Invalid beta_0 : {self.betas[0]}') |
| 80 | + if not 0.0 <= self.betas[1] < 1.0: |
| 81 | + raise ValueError(f'Invalid beta_1 : {self.betas[1]}') |
| 82 | + |
| 83 | + def __setstate__(self, state: STATE): |
| 84 | + super().__setstate__(state) |
| 85 | + for group in self.param_groups: |
| 86 | + group.setdefault('amsbound', False) |
| 87 | + |
| 88 | + def step(self, closure: CLOSURE = None) -> LOSS: |
| 89 | + loss: LOSS = None |
| 90 | + if closure is not None: |
| 91 | + loss = closure() |
| 92 | + |
| 93 | + for group, base_lr in zip(self.param_groups, self.base_lrs): |
| 94 | + for p in group['params']: |
| 95 | + if p.grad is None: |
| 96 | + continue |
| 97 | + |
| 98 | + grad = p.grad.data |
| 99 | + if grad.is_sparse: |
| 100 | + raise RuntimeError( |
| 101 | + 'AdaBound does not support sparse gradients' |
| 102 | + ) |
| 103 | + |
| 104 | + amsbound = group['amsbound'] |
| 105 | + |
| 106 | + state = self.state[p] |
| 107 | + |
| 108 | + if len(state) == 0: |
| 109 | + state['step'] = 0 |
| 110 | + state['exp_avg'] = torch.zeros_like(p) |
| 111 | + state['exp_avg_sq'] = torch.zeros_like(p) |
| 112 | + if amsbound: |
| 113 | + state['max_exp_avg_sq'] = torch.zeros_like(p) |
| 114 | + |
| 115 | + exp_avg, exp_avg_sq = state['exp_avg'], state['exp_avg_sq'] |
| 116 | + if amsbound: |
| 117 | + max_exp_avg_sq = state['max_exp_avg_sq'] |
| 118 | + beta1, beta2 = group['betas'] |
| 119 | + |
| 120 | + state['step'] += 1 |
| 121 | + |
| 122 | + if group['weight_decay'] != 0: |
| 123 | + grad = grad.add(group['weight_decay'], p.data) |
| 124 | + |
| 125 | + # Decay the first and second moment running average coefficient |
| 126 | + exp_avg.mul_(beta1).add_(1 - beta1, grad) |
| 127 | + exp_avg_sq.mul_(beta2).addcmul_(1 - beta2, grad, grad) |
| 128 | + if amsbound: |
| 129 | + torch.max(max_exp_avg_sq, exp_avg_sq, out=max_exp_avg_sq) |
| 130 | + denom = max_exp_avg_sq.sqrt().add_(group['eps']) |
| 131 | + else: |
| 132 | + denom = exp_avg_sq.sqrt().add_(group['eps']) |
| 133 | + |
| 134 | + bias_correction1 = 1 - beta1 ** state['step'] |
| 135 | + bias_correction2 = 1 - beta2 ** state['step'] |
| 136 | + step_size = ( |
| 137 | + group['lr'] |
| 138 | + * math.sqrt(bias_correction2) |
| 139 | + / bias_correction1 |
| 140 | + ) |
| 141 | + |
| 142 | + final_lr = group['final_lr'] * group['lr'] / base_lr |
| 143 | + lower_bound = final_lr * ( |
| 144 | + 1 - 1 / (group['gamma'] * state['step'] + 1) |
| 145 | + ) |
| 146 | + upper_bound = final_lr * ( |
| 147 | + 1 + 1 / (group['gamma'] * state['step']) |
| 148 | + ) |
| 149 | + step_size = torch.full_like(denom, step_size) |
| 150 | + step_size.div_(denom).clamp_(lower_bound, upper_bound).mul_( |
| 151 | + exp_avg |
| 152 | + ) |
| 153 | + |
| 154 | + p.data.add_(-step_size) |
| 155 | + |
| 156 | + return loss |
| 157 | + |
| 158 | + |
| 159 | +class AdaBoundW(Optimizer): |
| 160 | + """ |
| 161 | + Reference : https://github.com/Luolc/AdaBound |
| 162 | + Example : |
| 163 | + from pytorch_optimizer import AdaBoundW |
| 164 | + ... |
| 165 | + model = YourModel() |
| 166 | + optimizer = AdaBoundW(model.parameters()) |
| 167 | + ... |
| 168 | + for input, output in data: |
| 169 | + optimizer.zero_grad() |
| 170 | + loss = loss_function(output, model(input)) |
| 171 | + loss.backward() |
| 172 | + optimizer.step() |
| 173 | + """ |
| 174 | + |
| 175 | + def __init__( |
| 176 | + self, |
| 177 | + params: PARAMS, |
| 178 | + lr: float = 1e-3, |
| 179 | + betas: BETAS = (0.9, 0.999), |
| 180 | + final_lr: float = 0.1, |
| 181 | + gamma: float = 1e-3, |
| 182 | + eps: float = 1e-8, |
| 183 | + weight_decay: float = 0.0, |
| 184 | + amsbound: bool = False, |
| 185 | + ): |
| 186 | + """AdaBound optimizer with decoupled weight decay |
| 187 | + :param params: PARAMS. iterable of parameters to optimize or dicts defining parameter groups |
| 188 | + :param lr: float. learning rate |
| 189 | + :param final_lr: float. final learning rate |
| 190 | + :param betas: BETAS. coefficients used for computing running averages of gradient and the squared hessian trace |
| 191 | + :param gamma: float. convergence speed of the bound functions |
| 192 | + :param eps: float. term added to the denominator to improve numerical stability |
| 193 | + :param weight_decay: float. weight decay (L2 penalty) |
| 194 | + :param amsbound: bool. whether to use the AMSBound variant |
| 195 | + """ |
| 196 | + self.lr = lr |
| 197 | + self.betas = betas |
| 198 | + self.eps = eps |
| 199 | + self.weight_decay = weight_decay |
| 200 | + |
| 201 | + defaults: DEFAULT_PARAMETERS = dict( |
| 202 | + lr=lr, |
| 203 | + betas=betas, |
| 204 | + final_lr=final_lr, |
| 205 | + gamma=gamma, |
| 206 | + eps=eps, |
| 207 | + weight_decay=weight_decay, |
| 208 | + amsbound=amsbound, |
| 209 | + ) |
| 210 | + super().__init__(params, defaults) |
| 211 | + |
| 212 | + self.base_lrs = [group['lr'] for group in self.param_groups] |
| 213 | + |
| 214 | + def check_valid_parameters(self): |
| 215 | + if 0.0 > self.lr: |
| 216 | + raise ValueError(f'Invalid learning rate : {self.lr}') |
| 217 | + if 0.0 > self.eps: |
| 218 | + raise ValueError(f'Invalid eps : {self.eps}') |
| 219 | + if 0.0 > self.weight_decay: |
| 220 | + raise ValueError(f'Invalid weight_decay : {self.weight_decay}') |
| 221 | + if not 0.0 <= self.betas[0] < 1.0: |
| 222 | + raise ValueError(f'Invalid beta_0 : {self.betas[0]}') |
| 223 | + if not 0.0 <= self.betas[1] < 1.0: |
| 224 | + raise ValueError(f'Invalid beta_1 : {self.betas[1]}') |
| 225 | + |
| 226 | + def __setstate__(self, state: STATE): |
| 227 | + super().__setstate__(state) |
| 228 | + for group in self.param_groups: |
| 229 | + group.setdefault('amsbound', False) |
| 230 | + |
| 231 | + def step(self, closure: CLOSURE = None) -> LOSS: |
| 232 | + loss: LOSS = None |
| 233 | + if closure is not None: |
| 234 | + loss = closure() |
| 235 | + |
| 236 | + for group, base_lr in zip(self.param_groups, self.base_lrs): |
| 237 | + for p in group['params']: |
| 238 | + if p.grad is None: |
| 239 | + continue |
| 240 | + |
| 241 | + p.mul_(1 - base_lr * group['weight_decay']) |
| 242 | + |
| 243 | + grad = p.grad.data |
| 244 | + if grad.is_sparse: |
| 245 | + raise RuntimeError( |
| 246 | + 'AdaBound does not support sparse gradients' |
| 247 | + ) |
| 248 | + |
| 249 | + amsbound = group['amsbound'] |
| 250 | + |
| 251 | + state = self.state[p] |
| 252 | + |
| 253 | + if len(state) == 0: |
| 254 | + state['step'] = 0 |
| 255 | + state['exp_avg'] = torch.zeros_like(p) |
| 256 | + state['exp_avg_sq'] = torch.zeros_like(p) |
| 257 | + if amsbound: |
| 258 | + state['max_exp_avg_sq'] = torch.zeros_like(p) |
| 259 | + |
| 260 | + exp_avg, exp_avg_sq = state['exp_avg'], state['exp_avg_sq'] |
| 261 | + if amsbound: |
| 262 | + max_exp_avg_sq = state['max_exp_avg_sq'] |
| 263 | + beta1, beta2 = group['betas'] |
| 264 | + |
| 265 | + state['step'] += 1 |
| 266 | + |
| 267 | + # Decay the first and second moment running average coefficient |
| 268 | + exp_avg.mul_(beta1).add_(1 - beta1, grad) |
| 269 | + exp_avg_sq.mul_(beta2).addcmul_(1 - beta2, grad, grad) |
| 270 | + if amsbound: |
| 271 | + torch.max(max_exp_avg_sq, exp_avg_sq, out=max_exp_avg_sq) |
| 272 | + denom = max_exp_avg_sq.sqrt().add_(group['eps']) |
| 273 | + else: |
| 274 | + denom = exp_avg_sq.sqrt().add_(group['eps']) |
| 275 | + |
| 276 | + bias_correction1 = 1 - beta1 ** state['step'] |
| 277 | + bias_correction2 = 1 - beta2 ** state['step'] |
| 278 | + step_size = ( |
| 279 | + group['lr'] |
| 280 | + * math.sqrt(bias_correction2) |
| 281 | + / bias_correction1 |
| 282 | + ) |
| 283 | + |
| 284 | + final_lr = group['final_lr'] * group['lr'] / base_lr |
| 285 | + lower_bound = final_lr * ( |
| 286 | + 1 - 1 / (group['gamma'] * state['step'] + 1) |
| 287 | + ) |
| 288 | + upper_bound = final_lr * ( |
| 289 | + 1 + 1 / (group['gamma'] * state['step']) |
| 290 | + ) |
| 291 | + step_size = torch.full_like(denom, step_size) |
| 292 | + step_size.div_(denom).clamp_(lower_bound, upper_bound).mul_( |
| 293 | + exp_avg |
| 294 | + ) |
| 295 | + |
| 296 | + p.data.add_(-step_size) |
| 297 | + |
| 298 | + return loss |
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