Divyanshu Tak
V0-commit
5a169ab
import torch
import torch.nn as nn
import torch.optim as optim
from torch.utils.data import DataLoader
import wandb
from tqdm import tqdm
from torch.optim.lr_scheduler import CosineAnnealingWarmRestarts
from torch.cuda.amp import GradScaler, autocast
from sklearn.metrics import mean_absolute_error
import os
import sys
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from dataset2 import MedicalImageDatasetBalancedIntensity3D, TransformationMedicalImageDatasetBalancedIntensity3D
from model import Backbone, SingleScanModel, Classifier
from utils import BaseConfig
class BrainAgeTrainer(BaseConfig):
"""
A trainer class for brain age prediction models.
This class handles the complete training pipeline including model setup,
data loading, training loop, and validation.
Inherits from BaseConfig for configuration management.
"""
def __init__(self):
"""Initialize the trainer with model, data, and training setup."""
super().__init__()
self.setup_wandb()
self.setup_model()
self.setup_data()
self.setup_training()
## setup wandb logger
def setup_wandb(self):
config = self.get_config()
wandb.init(
project=config['logger']['project_name'],
name=config['logger']['run_name'],
config=config
)
def setup_model(self):
"""
Set up the model architecture.
Initializes the backbone and classifier blocks, and loads
checkpoints
"""
self.backbone = Backbone()
self.classifier = Classifier(d_model=2048)
self.model = SingleScanModel(self.backbone, self.classifier)
# Load BrainIACs weights
config = self.get_config()
if config["train"]["finetune"] == "yes":
checkpoint = torch.load(config["train"]["weights"], map_location=self.device)
state_dict = checkpoint["state_dict"]
filtered_state_dict = {}
for key, value in state_dict.items():
new_key = key.replace("module.", "backbone.") if key.startswith("module.") else key
filtered_state_dict[new_key] = value
self.model.backbone.load_state_dict(filtered_state_dict, strict=False)
print("Pretrained weights loaded!")
# Freeze backbone if specified
if config["train"]["freeze"] == "yes":
for param in self.model.backbone.parameters():
param.requires_grad = False
print("Backbone weights frozen!")
self.model = self.model.to(self.device)
def setup_data(self):
"""
Set up data loaders for training and validation.
Inherit configuration from the base config
"""
config = self.get_config()
self.train_dataset = TransformationMedicalImageDatasetBalancedIntensity3D(
csv_path=config['data']['train_csv'],
root_dir=config["data"]["root_dir"]
)
self.val_dataset = MedicalImageDatasetBalancedIntensity3D(
csv_path=config['data']['val_csv'],
root_dir=config["data"]["root_dir"]
)
self.train_loader = DataLoader(
self.train_dataset,
batch_size=config["data"]["batch_size"],
shuffle=True,
collate_fn=self.custom_collate,
num_workers=config["data"]["num_workers"]
)
self.val_loader = DataLoader(
self.val_dataset,
batch_size=1,
shuffle=False,
collate_fn=self.custom_collate,
num_workers=1
)
def setup_training(self):
"""
Set up training config with loss, scheduler, optimizer.
"""
config = self.get_config()
self.criterion = nn.MSELoss()
self.optimizer = optim.Adam(
self.model.parameters(),
lr=config['optim']['lr'],
weight_decay=config["optim"]["weight_decay"]
)
self.scheduler = CosineAnnealingWarmRestarts(self.optimizer, T_0=50, T_mult=2)
self.scaler = GradScaler()
def train(self):
"""
main training loop
"""
config = self.get_config()
max_epochs = config['optim']['max_epochs']
best_val_loss = float('inf')
best_val_mae = float('inf')
for epoch in range(max_epochs):
train_loss = self.train_epoch(epoch, max_epochs)
val_loss, mae = self.validate_epoch(epoch, max_epochs)
# Save best model
if (val_loss <= best_val_loss) and (mae <= best_val_mae):
print(f"Improved Val Loss from {best_val_loss:.4f} to {val_loss:.4f}")
print(f"Improved Val MAE from {best_val_mae:.4f} to {mae:.4f}")
best_val_loss = val_loss
best_val_mae = mae
self.save_checkpoint(epoch, val_loss, mae)
wandb.finish()
def train_epoch(self, epoch, max_epochs):
"""
Train pass.
Args:
epoch (int): Current epoch number
max_epochs (int): Total number of epochs
Returns:
float: Average training loss for the epoch
"""
self.model.train()
train_loss = 0.0
for sample in tqdm(self.train_loader, desc=f"Training Epoch {epoch}/{max_epochs-1}"):
inputs = sample['image'].to(self.device)
labels = sample['label'].float().to(self.device)
self.optimizer.zero_grad()
with autocast():
outputs = self.model(inputs)
loss = self.criterion(outputs, labels.unsqueeze(1))
self.scaler.scale(loss).backward()
self.scaler.step(self.optimizer)
self.scaler.update()
train_loss += loss.item() * inputs.size(0)
train_loss = train_loss / len(self.train_loader.dataset)
wandb.log({"Train Loss": train_loss})
return train_loss
def validate_epoch(self, epoch, max_epochs):
"""
Validation pass.
Args:
epoch (int): Current epoch number
max_epochs (int): Total number of epochs
Returns:
tuple: (validation_loss, mean_absolute_error)
"""
self.model.eval()
val_loss = 0.0
all_labels = []
all_preds = []
with torch.no_grad():
for sample in tqdm(self.val_loader, desc=f"Validation Epoch {epoch}/{max_epochs-1}"):
inputs = sample['image'].to(self.device)
labels = sample['label'].float().to(self.device)
outputs = self.model(inputs)
loss = self.criterion(outputs, labels.unsqueeze(1))
val_loss += loss.item() * inputs.size(0)
all_labels.extend(labels.cpu().numpy().flatten())
all_preds.extend(outputs.cpu().numpy().flatten())
val_loss = val_loss / len(self.val_loader.dataset)
mae = mean_absolute_error(all_labels, all_preds)
wandb.log({"Val Loss": val_loss, "MAE": mae})
self.scheduler.step(val_loss)
print(f"Epoch {epoch}/{max_epochs-1} Val Loss: {val_loss:.4f} MAE: {mae:.4f}")
return val_loss, mae
def save_checkpoint(self, epoch, loss, mae):
"""
Save model checkpoint.
"""
config = self.get_config()
checkpoint = {
'model_state_dict': self.model.state_dict(),
'loss': loss,
'epoch': epoch,
}
save_path = os.path.join(
config['logger']['save_dir'],
config['logger']['save_name'].format(epoch=epoch, loss=loss, metric=mae)
)
torch.save(checkpoint, save_path)
if __name__ == "__main__":
trainer = BrainAgeTrainer()
trainer.train()