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import torch |
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from loguru import logger |
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from torch import Tensor |
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from torch.cuda.amp import GradScaler, autocast |
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from tqdm import tqdm |
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from yolo.config.config import Config, TrainConfig |
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from yolo.model.yolo import YOLO |
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from yolo.tools.model_helper import EMA, get_optimizer, get_scheduler |
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from yolo.utils.loss import get_loss_function |
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class Trainer: |
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def __init__(self, model: YOLO, cfg: Config, device): |
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train_cfg: TrainConfig = cfg.hyper.train |
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self.model = model.to(device) |
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self.device = device |
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self.optimizer = get_optimizer(model.parameters(), train_cfg.optimizer) |
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self.scheduler = get_scheduler(self.optimizer, train_cfg.scheduler) |
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self.loss_fn = get_loss_function(cfg) |
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if train_cfg.ema.get("enabled", False): |
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self.ema = EMA(model, decay=train_cfg.ema.decay) |
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else: |
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self.ema = None |
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self.scaler = GradScaler() |
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def train_one_batch(self, data: Tensor, targets: Tensor, progress: tqdm): |
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data, targets = data.to(self.device), targets.to(self.device) |
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self.optimizer.zero_grad() |
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with autocast(): |
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outputs = self.model(data) |
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loss, loss_item = self.loss_fn(outputs, targets) |
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loss_iou, loss_dfl, loss_cls = loss_item |
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progress.set_description(f"Loss IoU: {loss_iou:.5f}, DFL: {loss_dfl:.5f}, CLS: {loss_cls:.5f}") |
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self.scaler.scale(loss).backward() |
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self.scaler.step(self.optimizer) |
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self.scaler.update() |
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if self.ema: |
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self.ema.update() |
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return loss.item() |
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def train_one_epoch(self, dataloader): |
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self.model.train() |
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total_loss = 0 |
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with tqdm(dataloader, desc="Training") as progress: |
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for data, targets in progress: |
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loss = self.train_one_batch(data, targets, progress) |
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total_loss += loss |
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if self.scheduler: |
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self.scheduler.step() |
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return total_loss / len(dataloader) |
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def save_checkpoint(self, epoch: int, filename="checkpoint.pt"): |
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checkpoint = { |
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"epoch": epoch, |
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"model_state_dict": self.model.state_dict(), |
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"optimizer_state_dict": self.optimizer.state_dict(), |
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} |
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if self.ema: |
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self.ema.apply_shadow() |
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checkpoint["model_state_dict_ema"] = self.model.state_dict() |
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self.ema.restore() |
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torch.save(checkpoint, filename) |
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def train(self, dataloader, num_epochs): |
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logger.info("start train") |
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for epoch in range(num_epochs): |
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epoch_loss = self.train_one_epoch(dataloader) |
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logger.info(f"Epoch {epoch+1}/{num_epochs}, Loss: {epoch_loss:.4f}") |
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if (epoch + 1) % 5 == 0: |
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self.save_checkpoint(epoch, f"checkpoint_epoch_{epoch+1}.pth") |
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