test_moe_model.py

import os
import torch
import torchaudio
import torchvision
import numpy as np
import json
from torch.utils.data import Dataset, DataLoader
import sys
from tqdm import tqdm

# Add parent directory to path to import the preprocess functions
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from preprocess import process_audio_data, process_image_data

# Import the WatermelonDataset and WatermelonModelModular from the evaluate_backbones.py file
from evaluate_backbones import WatermelonDataset, WatermelonModelModular, IMAGE_BACKBONES, AUDIO_BACKBONES

# Print library versions
print(f"\033[92mINFO\033[0m: PyTorch version: {torch.__version__}")
print(f"\033[92mINFO\033[0m: Torchaudio version: {torchaudio.__version__}")
print(f"\033[92mINFO\033[0m: Torchvision version: {torchvision.__version__}")

# Device selection
device = torch.device(
    "cuda" if torch.cuda.is_available() 
    else "mps" if torch.backends.mps.is_available() 
    else "cpu"
)
print(f"\033[92mINFO\033[0m: Using device: {device}")

# Define the top-performing models based on the previous evaluation
TOP_MODELS = [
    {"image_backbone": "efficientnet_b3", "audio_backbone": "transformer"},
    {"image_backbone": "efficientnet_b0", "audio_backbone": "transformer"},
    {"image_backbone": "resnet50", "audio_backbone": "transformer"}
]

# Define class for the MoE model
class WatermelonMoEModel(torch.nn.Module):
    def __init__(self, model_configs, model_dir="test_models", weights=None):
        """
        Mixture of Experts model that combines multiple backbone models.
        
        Args:
            model_configs: List of dictionaries with 'image_backbone' and 'audio_backbone' keys
            model_dir: Directory where model checkpoints are stored
            weights: Optional list of weights for each model (None for equal weighting)
        """
        super(WatermelonMoEModel, self).__init__()
        self.models = []
        self.model_configs = model_configs
        
        # Load each model
        for config in model_configs:
            img_backbone = config["image_backbone"]
            audio_backbone = config["audio_backbone"]
            
            # Initialize model
            model = WatermelonModelModular(img_backbone, audio_backbone)
            
            # Load weights
            model_path = os.path.join(model_dir, f"{img_backbone}_{audio_backbone}_model.pt")
            if os.path.exists(model_path):
                print(f"\033[92mINFO\033[0m: Loading model {img_backbone}_{audio_backbone} from {model_path}")
                model.load_state_dict(torch.load(model_path, map_location=device))
            else:
                print(f"\033[91mERR!\033[0m: Model checkpoint not found at {model_path}")
                continue
                
            model.to(device)
            model.eval()  # Set to evaluation mode
            self.models.append(model)
        
        # Set model weights (uniform by default)
        if weights:
            assert len(weights) == len(self.models), "Number of weights must match number of models"
            self.weights = weights
        else:
            self.weights = [1.0 / len(self.models)] * len(self.models)
            
        print(f"\033[92mINFO\033[0m: Loaded {len(self.models)} models for MoE ensemble")
        print(f"\033[92mINFO\033[0m: Model weights: {self.weights}")

    def forward(self, mfcc, image):
        """
        Forward pass through the MoE model.
        Returns the weighted average of all model outputs.
        """
        outputs = []
        
        # Get outputs from each model
        with torch.no_grad():
            for i, model in enumerate(self.models):
                output = model(mfcc, image)
                outputs.append(output * self.weights[i])
        
        # Return weighted average
        return torch.sum(torch.stack(outputs), dim=0)


def evaluate_moe_model(data_dir, model_dir="test_models", weights=None):
    """
    Evaluate the MoE model on the test set.
    """
    # Load dataset
    print(f"\033[92mINFO\033[0m: Loading dataset from {data_dir}")
    dataset = WatermelonDataset(data_dir)
    n_samples = len(dataset)

    # Split dataset
    train_size = int(0.7 * n_samples)
    val_size = int(0.2 * n_samples)
    test_size = n_samples - train_size - val_size

    _, _, test_dataset = torch.utils.data.random_split(
        dataset, [train_size, val_size, test_size]
    )

    # Use a reasonable batch size
    batch_size = 8
    test_loader = DataLoader(test_dataset, batch_size=batch_size, shuffle=False)

    # Initialize MoE model
    moe_model = WatermelonMoEModel(TOP_MODELS, model_dir, weights)
    moe_model.eval()

    # Evaluation metrics
    mae_criterion = torch.nn.L1Loss()
    mse_criterion = torch.nn.MSELoss()
    
    test_mae = 0.0
    test_mse = 0.0
    
    print(f"\033[92mINFO\033[0m: Evaluating MoE model on {len(test_dataset)} test samples")
    
    # Individual model predictions for analysis
    individual_predictions = {f"{config['image_backbone']}_{config['audio_backbone']}": [] 
                             for config in TOP_MODELS}
    true_labels = []
    moe_predictions = []
    
    # Evaluation loop
    test_iterator = tqdm(test_loader, desc="Testing MoE")
    
    with torch.no_grad():
        for i, (mfcc, image, label) in enumerate(test_iterator):
            try:
                mfcc, image, label = mfcc.to(device), image.to(device), label.to(device)
                
                # Store individual model outputs for analysis
                for j, model in enumerate(moe_model.models):
                    config = TOP_MODELS[j]
                    model_name = f"{config['image_backbone']}_{config['audio_backbone']}"
                    output = model(mfcc, image)
                    individual_predictions[model_name].extend(output.view(-1).cpu().numpy())
                
                # Get MoE prediction
                output = moe_model(mfcc, image)
                moe_predictions.extend(output.view(-1).cpu().numpy())
                
                # Store true labels
                label = label.view(-1, 1).float()
                true_labels.extend(label.view(-1).cpu().numpy())
                
                # Calculate metrics
                mae = mae_criterion(output, label)
                mse = mse_criterion(output, label)
                
                test_mae += mae.item()
                test_mse += mse.item()
                
                test_iterator.set_postfix({"MAE": f"{mae.item():.4f}", "MSE": f"{mse.item():.4f}"})
                
                # Clean up memory
                if device.type == 'cuda':
                    del mfcc, image, label, output, mae, mse
                    torch.cuda.empty_cache()
                
            except Exception as e:
                print(f"\033[91mERR!\033[0m: Error in test batch {i}: {e}")
                if device.type == 'cuda':
                    torch.cuda.empty_cache()
                continue

    # Calculate average metrics
    avg_test_mae = test_mae / len(test_loader) if len(test_loader) > 0 else float('inf')
    avg_test_mse = test_mse / len(test_loader) if len(test_loader) > 0 else float('inf')
    
    print(f"\n\033[92mINFO\033[0m: === MoE Model Results ===")
    print(f"Test MAE: {avg_test_mae:.4f}")
    print(f"Test MSE: {avg_test_mse:.4f}")
    
    # Compare with individual models
    print(f"\n\033[92mINFO\033[0m: === Comparison with Individual Models ===")
    print(f"{'Model':<30} {'Test MAE':<15}")
    print("="*45)
    
    # Load previous results
    results_file = "backbone_evaluation_results.json"
    if os.path.exists(results_file):
        with open(results_file, 'r') as f:
            previous_results = json.load(f)
        
        # Filter results for our top models
        for config in TOP_MODELS:
            img_backbone = config["image_backbone"]
            audio_backbone = config["audio_backbone"]
            
            for result in previous_results:
                if result["image_backbone"] == img_backbone and result["audio_backbone"] == audio_backbone:
                    print(f"{img_backbone}_{audio_backbone:<20} {result['test_mae']:<15.4f}")
    
    print(f"MoE (Ensemble)               {avg_test_mae:<15.4f}")
    
    # Save results and predictions
    results = {
        "moe_test_mae": float(avg_test_mae),
        "moe_test_mse": float(avg_test_mse),
        "true_labels": [float(x) for x in true_labels],
        "moe_predictions": [float(x) for x in moe_predictions],
        "individual_predictions": {key: [float(x) for x in values] 
                                  for key, values in individual_predictions.items()}
    }
    
    with open("moe_evaluation_results.json", 'w') as f:
        json.dump(results, f, indent=4)
    
    print(f"\033[92mINFO\033[0m: Results saved to moe_evaluation_results.json")
    
    return avg_test_mae, avg_test_mse


if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="Test Mixture of Experts (MoE) Model for Watermelon Sweetness Prediction")
    parser.add_argument(
        "--data_dir", 
        type=str, 
        default="../cleaned", 
        help="Path to the cleaned dataset directory"
    )
    parser.add_argument(
        "--model_dir", 
        type=str, 
        default="test_models", 
        help="Directory containing model checkpoints"
    )
    parser.add_argument(
        "--weighting", 
        type=str, 
        choices=["uniform", "performance"], 
        default="uniform", 
        help="How to weight the models (uniform or based on performance)"
    )
    
    args = parser.parse_args()
    
    # Determine weights based on argument
    weights = None
    if args.weighting == "performance":
        # Weights inversely proportional to the MAE (better models get higher weights)
        # These are the MAE values from the provided results
        mae_values = [0.3635, 0.3765, 0.3959]  # efficientnet_b3+transformer, efficientnet_b0+transformer, resnet50+transformer
        
        # Convert to weights (inverse of MAE, normalized)
        inverse_mae = [1/mae for mae in mae_values]
        total = sum(inverse_mae)
        weights = [val/total for val in inverse_mae]
        
        print(f"\033[92mINFO\033[0m: Using performance-based weights: {weights}")
    else:
        print(f"\033[92mINFO\033[0m: Using uniform weights")
    
    # Evaluate the MoE model
    evaluate_moe_model(args.data_dir, args.model_dir, weights)