197 lines
7.1 KiB
Python
197 lines
7.1 KiB
Python
import importlib
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import torch
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from torch import optim
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import numpy as np
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from inspect import isfunction
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from PIL import Image, ImageDraw, ImageFont
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def log_txt_as_img(wh, xc, size=10):
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# wh a tuple of (width, height)
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# xc a list of captions to plot
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b = len(xc)
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txts = list()
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for bi in range(b):
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txt = Image.new("RGB", wh, color="white")
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draw = ImageDraw.Draw(txt)
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font = ImageFont.truetype('data/DejaVuSans.ttf', size=size)
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nc = int(40 * (wh[0] / 256))
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lines = "\n".join(xc[bi][start:start + nc] for start in range(0, len(xc[bi]), nc))
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try:
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draw.text((0, 0), lines, fill="black", font=font)
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except UnicodeEncodeError:
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print("Cant encode string for logging. Skipping.")
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txt = np.array(txt).transpose(2, 0, 1) / 127.5 - 1.0
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txts.append(txt)
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txts = np.stack(txts)
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txts = torch.tensor(txts)
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return txts
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def ismap(x):
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if not isinstance(x, torch.Tensor):
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return False
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return (len(x.shape) == 4) and (x.shape[1] > 3)
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def isimage(x):
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if not isinstance(x,torch.Tensor):
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return False
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return (len(x.shape) == 4) and (x.shape[1] == 3 or x.shape[1] == 1)
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def exists(x):
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return x is not None
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def default(val, d):
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if exists(val):
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return val
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return d() if isfunction(d) else d
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def mean_flat(tensor):
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"""
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https://github.com/openai/guided-diffusion/blob/27c20a8fab9cb472df5d6bdd6c8d11c8f430b924/guided_diffusion/nn.py#L86
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Take the mean over all non-batch dimensions.
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"""
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return tensor.mean(dim=list(range(1, len(tensor.shape))))
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def count_params(model, verbose=False):
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total_params = sum(p.numel() for p in model.parameters())
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if verbose:
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print(f"{model.__class__.__name__} has {total_params*1.e-6:.2f} M params.")
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return total_params
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def instantiate_from_config(config):
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if not "target" in config:
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if config == '__is_first_stage__':
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return None
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elif config == "__is_unconditional__":
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return None
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raise KeyError("Expected key `target` to instantiate.")
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return get_obj_from_str(config["target"])(**config.get("params", dict()))
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def get_obj_from_str(string, reload=False):
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module, cls = string.rsplit(".", 1)
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if reload:
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module_imp = importlib.import_module(module)
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importlib.reload(module_imp)
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return getattr(importlib.import_module(module, package=None), cls)
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class AdamWwithEMAandWings(optim.Optimizer):
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# credit to https://gist.github.com/crowsonkb/65f7265353f403714fce3b2595e0b298
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def __init__(self, params, lr=1.e-3, betas=(0.9, 0.999), eps=1.e-8, # TODO: check hyperparameters before using
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weight_decay=1.e-2, amsgrad=False, ema_decay=0.9999, # ema decay to match previous code
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ema_power=1., param_names=()):
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"""AdamW that saves EMA versions of the parameters."""
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if not 0.0 <= lr:
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raise ValueError("Invalid learning rate: {}".format(lr))
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if not 0.0 <= eps:
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raise ValueError("Invalid epsilon value: {}".format(eps))
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if not 0.0 <= betas[0] < 1.0:
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raise ValueError("Invalid beta parameter at index 0: {}".format(betas[0]))
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if not 0.0 <= betas[1] < 1.0:
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raise ValueError("Invalid beta parameter at index 1: {}".format(betas[1]))
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if not 0.0 <= weight_decay:
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raise ValueError("Invalid weight_decay value: {}".format(weight_decay))
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if not 0.0 <= ema_decay <= 1.0:
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raise ValueError("Invalid ema_decay value: {}".format(ema_decay))
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defaults = dict(lr=lr, betas=betas, eps=eps,
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weight_decay=weight_decay, amsgrad=amsgrad, ema_decay=ema_decay,
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ema_power=ema_power, param_names=param_names)
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super().__init__(params, defaults)
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def __setstate__(self, state):
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super().__setstate__(state)
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for group in self.param_groups:
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group.setdefault('amsgrad', False)
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@torch.no_grad()
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def step(self, closure=None):
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"""Performs a single optimization step.
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Args:
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closure (callable, optional): A closure that reevaluates the model
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and returns the loss.
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"""
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loss = None
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if closure is not None:
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with torch.enable_grad():
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loss = closure()
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for group in self.param_groups:
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params_with_grad = []
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grads = []
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exp_avgs = []
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exp_avg_sqs = []
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ema_params_with_grad = []
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state_sums = []
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max_exp_avg_sqs = []
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state_steps = []
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amsgrad = group['amsgrad']
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beta1, beta2 = group['betas']
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ema_decay = group['ema_decay']
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ema_power = group['ema_power']
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for p in group['params']:
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if p.grad is None:
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continue
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params_with_grad.append(p)
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if p.grad.is_sparse:
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raise RuntimeError('AdamW does not support sparse gradients')
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grads.append(p.grad)
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state = self.state[p]
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# State initialization
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if len(state) == 0:
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state['step'] = 0
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# Exponential moving average of gradient values
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state['exp_avg'] = torch.zeros_like(p, memory_format=torch.preserve_format)
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# Exponential moving average of squared gradient values
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state['exp_avg_sq'] = torch.zeros_like(p, memory_format=torch.preserve_format)
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if amsgrad:
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# Maintains max of all exp. moving avg. of sq. grad. values
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state['max_exp_avg_sq'] = torch.zeros_like(p, memory_format=torch.preserve_format)
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# Exponential moving average of parameter values
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state['param_exp_avg'] = p.detach().float().clone()
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exp_avgs.append(state['exp_avg'])
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exp_avg_sqs.append(state['exp_avg_sq'])
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ema_params_with_grad.append(state['param_exp_avg'])
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if amsgrad:
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max_exp_avg_sqs.append(state['max_exp_avg_sq'])
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# update the steps for each param group update
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state['step'] += 1
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# record the step after step update
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state_steps.append(state['step'])
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optim._functional.adamw(params_with_grad,
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grads,
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exp_avgs,
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exp_avg_sqs,
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max_exp_avg_sqs,
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state_steps,
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amsgrad=amsgrad,
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beta1=beta1,
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beta2=beta2,
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lr=group['lr'],
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weight_decay=group['weight_decay'],
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eps=group['eps'],
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maximize=False)
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cur_ema_decay = min(ema_decay, 1 - state['step'] ** -ema_power)
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for param, ema_param in zip(params_with_grad, ema_params_with_grad):
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ema_param.mul_(cur_ema_decay).add_(param.float(), alpha=1 - cur_ema_decay)
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return loss |