import os import torch import torch.nn as nn from torch.utils.data import Dataset, DataLoader from timm.models.layers import trunc_normal_ from einops import rearrange import numpy as np from typing import List, Dict, Any import matplotlib.pyplot as plt import json import random import time from clean_eval import evaluate as rollout_evaluate # ============================================================================ # 1. PYTORCH DATASET CLASS FOR TIME-STEPPED DATA # ============================================================================ class TimeStepDataset(Dataset): """Dataset for flattened timestep training data""" def __init__(self, pt_file_path: str): if not os.path.exists(pt_file_path): raise FileNotFoundError(f"Dataset file not found at: {pt_file_path}") self.data = torch.load(pt_file_path, weights_only=False) print(f"Loaded {len(self.data)} timesteps from {pt_file_path}") def __len__(self) -> int: return len(self.data) def __getitem__(self, idx: int) -> Dict[str, Any]: sample = self.data[idx] return { 'coordinates': sample['coordinates'], 'node_type': sample['node_type'], 'current_velocities': sample['current_velocities'], 'target_velocities': sample['target_velocities'], 'meta_info': sample['meta_info'] } class TrajectoryDataset(Dataset): """Dataset for full trajectory evaluation data""" def __init__(self, pt_file_path: str): if not os.path.exists(pt_file_path): raise FileNotFoundError(f"Dataset file not found at: {pt_file_path}") self.trajectories = torch.load(pt_file_path, weights_only=False) print(f"Loaded {len(self.trajectories)} trajectories from {pt_file_path}") def __len__(self) -> int: return len(self.trajectories) def __getitem__(self, idx: int) -> Dict[str, Any]: return self.trajectories[idx] # ============================================================================ # 2. TRANSOLVER MODEL ARCHITECTURE (Adapted for Time-Dependent Prediction) # ============================================================================ ACTIVATION = {'gelu': nn.GELU, 'tanh': nn.Tanh, 'sigmoid': nn.Sigmoid, 'relu': nn.ReLU, 'leaky_relu': nn.LeakyReLU(0.1)} class MLP(nn.Module): def __init__(self, n_input, n_hidden, n_output, n_layers=1, act='gelu', res=True): super(MLP, self).__init__() if act in ACTIVATION.keys(): act = ACTIVATION[act] else: raise NotImplementedError self.linear_pre = nn.Sequential(nn.Linear(n_input, n_hidden), act()) self.linear_post = nn.Linear(n_hidden, n_output) self.linears = nn.ModuleList([nn.Sequential(nn.Linear(n_hidden, n_hidden), act()) for _ in range(n_layers)]) self.res = res def forward(self, x): x = self.linear_pre(x) for i in range(len(self.linears)): if self.res: x = self.linears[i](x) + x else: x = self.linears[i](x) x = self.linear_post(x) return x class Physics_Attention_Irregular_Mesh(nn.Module): def __init__(self, dim, heads=8, dim_head=64, dropout=0., slice_num=64): super().__init__() inner_dim = dim_head * heads self.dim_head = dim_head self.heads = heads self.scale = dim_head ** -0.5 self.softmax = nn.Softmax(dim=-1) self.dropout = nn.Dropout(dropout) self.temperature = nn.Parameter(torch.ones([1, heads, 1, 1]) * 0.5) self.in_project_x = nn.Linear(dim, inner_dim) self.in_project_fx = nn.Linear(dim, inner_dim) self.in_project_slice = nn.Linear(dim_head, slice_num) torch.nn.init.orthogonal_(self.in_project_slice.weight) self.to_q = nn.Linear(dim_head, dim_head, bias=False) self.to_k = nn.Linear(dim_head, dim_head, bias=False) self.to_v = nn.Linear(dim_head, dim_head, bias=False) self.to_out = nn.Sequential(nn.Linear(inner_dim, dim), nn.Dropout(dropout)) def forward(self, x): B, N, C = x.shape fx_mid = self.in_project_fx(x).reshape(B, N, self.heads, self.dim_head).permute(0, 2, 1, 3).contiguous() x_mid = self.in_project_x(x).reshape(B, N, self.heads, self.dim_head).permute(0, 2, 1, 3).contiguous() slice_weights = self.softmax(self.in_project_slice(x_mid) / self.temperature) slice_norm = slice_weights.sum(2) slice_token = torch.einsum("bhnc,bhng->bhgc", fx_mid, slice_weights) slice_token = slice_token / ((slice_norm + 1e-5)[:, :, :, None].repeat(1, 1, 1, self.dim_head)) q_slice_token = self.to_q(slice_token) k_slice_token = self.to_k(slice_token) v_slice_token = self.to_v(slice_token) dots = torch.matmul(q_slice_token, k_slice_token.transpose(-1, -2)) * self.scale attn = self.softmax(dots) attn = self.dropout(attn) out_slice_token = torch.matmul(attn, v_slice_token) out_x = torch.einsum("bhgc,bhng->bhnc", out_slice_token, slice_weights) out_x = rearrange(out_x, 'b h n d -> b n (h d)') out = self.to_out(out_x) return out class Transolver_block(nn.Module): def __init__(self, num_heads, hidden_dim, dropout, act='gelu', mlp_ratio=4, last_layer=False, out_dim=1, slice_num=32): super().__init__() self.last_layer = last_layer self.ln_1 = nn.LayerNorm(hidden_dim) self.Attn = Physics_Attention_Irregular_Mesh(hidden_dim, heads=num_heads, dim_head=hidden_dim // num_heads, dropout=dropout, slice_num=slice_num) self.ln_2 = nn.LayerNorm(hidden_dim) self.mlp = MLP(hidden_dim, hidden_dim * mlp_ratio, hidden_dim, n_layers=0, res=False, act=act) if self.last_layer: self.ln_3 = nn.LayerNorm(hidden_dim) self.mlp2 = nn.Linear(hidden_dim, out_dim) def forward(self, fx): fx2 = self.Attn(self.ln_1(fx)) + fx fx = self.mlp(self.ln_2(fx2)) + fx2 if self.last_layer: return self.mlp2(self.ln_3(fx)) return fx class Model(nn.Module): def __init__(self, in_dim=13, out_dim=3, n_layers=8, n_hidden=256, dropout=0, n_head=8, act='gelu', mlp_ratio=2, slice_num=32): super(Model, self).__init__() self.preprocess = MLP(in_dim, n_hidden * 2, n_hidden, n_layers=0, res=False, act=act) self.n_hidden = n_hidden self.blocks = nn.ModuleList([Transolver_block(num_heads=n_head, hidden_dim=n_hidden, dropout=dropout, act=act, mlp_ratio=mlp_ratio, out_dim=out_dim, slice_num=slice_num, last_layer=(_ == n_layers - 1)) for _ in range(n_layers)]) self.initialize_weights() self.placeholder = nn.Parameter((1 / n_hidden) * torch.rand(n_hidden, dtype=torch.float)) def initialize_weights(self): self.apply(self._init_weights) def _init_weights(self, m): if isinstance(m, nn.Linear): trunc_normal_(m.weight, std=0.02) if isinstance(m, nn.Linear) and m.bias is not None: nn.init.constant_(m.bias, 0) elif isinstance(m, (nn.LayerNorm, nn.BatchNorm1d)): nn.init.constant_(m.bias, 0) nn.init.constant_(m.weight, 1.0) def forward(self, x): fx = self.preprocess(x) fx = fx + self.placeholder[None, None, :] for block in self.blocks: fx = block(fx) return fx # ============================================================================ # 3. CHECKPOINTING FUNCTIONS # ============================================================================ def save_checkpoint(model, optimizer, scheduler, epoch, loss, path, norm_stats): """Save training checkpoint""" checkpoint = { 'epoch': epoch, 'model_state_dict': model.state_dict(), 'optimizer_state_dict': optimizer.state_dict(), 'scheduler_state_dict': scheduler.state_dict() if scheduler else None, 'loss': loss, 'norm_stats': norm_stats # Save normalization stats } torch.save(checkpoint, path) print(f"Checkpoint saved: {path}") def load_checkpoint(model, optimizer, scheduler, path): """Load training checkpoint""" checkpoint = torch.load(path, map_location='cpu') model.load_state_dict(checkpoint['model_state_dict']) optimizer.load_state_dict(checkpoint['optimizer_state_dict']) if scheduler and checkpoint.get('scheduler_state_dict'): scheduler.load_state_dict(checkpoint['scheduler_state_dict']) # Load norm_stats if they exist, otherwise return None norm_stats = checkpoint.get('norm_stats', None) if norm_stats is None: print("Warning: Normalization stats not found in checkpoint.") return checkpoint['epoch'], checkpoint['loss'], norm_stats # ============================================================================ # 4. EVALUATION FUNCTIONS # ============================================================================ def create_wall_mask(node_type): """Create mask to ignore wall nodes during loss calculation""" wall_class_index = 5 # Assuming walls are class 5 node_class_indices = torch.argmax(node_type, dim=-1) mask = (node_class_indices != wall_class_index).float().unsqueeze(-1) return mask def evaluate_rollout(model, trajectory_loader, device, norm_stats): """Run rollout evaluation on full trajectories""" model.eval() results = [] print(f"Starting rollout evaluation on {len(trajectory_loader)} trajectories...") with torch.no_grad(): for i, trajectory in enumerate(trajectory_loader): try: print(f"\nProcessing trajectory {i+1}/{len(trajectory_loader)}") # Since trajectory_loader has batch_size=1, we need to extract the single trajectory single_trajectory = {} for key, value in trajectory.items(): if key != 'meta_info': # Remove the batch dimension single_trajectory[key] = value.squeeze(0) else: # meta_info is special - it's a dict where each value is a list/tensor due to batching # We need to extract the first element from each value in the meta_info dict single_trajectory[key] = {} for meta_key, meta_value in value.items(): if isinstance(meta_value, (list, tuple)): single_trajectory[key][meta_key] = meta_value[0] elif isinstance(meta_value, dict): # Handle nested dictionaries (like node_type_counts) single_trajectory[key][meta_key] = {} for nested_key, nested_value in meta_value.items(): if isinstance(nested_value, (list, tuple)): single_trajectory[key][meta_key][nested_key] = nested_value[0] elif torch.is_tensor(nested_value) and nested_value.numel() > 1: single_trajectory[key][meta_key][nested_key] = nested_value[0] else: single_trajectory[key][meta_key][nested_key] = nested_value elif torch.is_tensor(meta_value) and meta_value.numel() > 1: # For tensors with more than one element, take the first element single_trajectory[key][meta_key] = meta_value[0] else: # For scalars or other types, keep as is single_trajectory[key][meta_key] = meta_value # Pass the normalization statistics to the evaluation function _, traj_result = rollout_evaluate(model, single_trajectory, norm_stats) results.append(traj_result) print(f"Successfully processed trajectory {i+1}") except Exception as e: print(f"Error processing trajectory {i+1}: {str(e)}") print(f"Trajectory data shapes:") for key, value in trajectory.items(): if hasattr(value, 'shape'): print(f" {key}: {value.shape}") else: print(f" {key}: {type(value)} - {value}") raise e print(f"Completed rollout evaluation on {len(results)} trajectories") return results # ============================================================================ # 5. MAIN TRAINING SCRIPT # ============================================================================ def main(): script_start_time = time.time() # --- CONFIGURATION --- preprocessed_dir = r"/home/gd_user1/AnK/project_PINN/cleanroom/rawdataset" base_filename = "final_data_timestep_data" output_dir = r"/home/gd_user1/AnK/project_PINN/cleanroom/second_output/output_2" train_pt_path = os.path.join(preprocessed_dir, f"{base_filename}_train.pt") val_pt_path = os.path.join(preprocessed_dir, f"{base_filename}_test.pt") os.makedirs(output_dir, exist_ok=True) hparams = { 'lr': 0.0005, 'batch_size': 1, 'nb_epochs': 400, 'in_dim': 13, # coordinates(3) + node_type(6) + current_vel(3) + inlet_vel(1) 'out_dim': 3, 'n_hidden': 256, 'n_layers': 6, 'n_head': 8, 'slice_num': 32, 'checkpoint_freq': 10, 'eval_freq': 10 } # --- SETUP --- device = torch.device('cuda' if torch.cuda.is_available() else 'cpu') print(f"Using device: {device}") if torch.cuda.is_available(): print(f"GPU: {torch.cuda.get_device_name(0)}") print(f"CUDA version: {torch.version.cuda}") # Set random seeds for reproducibility torch.manual_seed(42) random.seed(42) np.random.seed(42) # --- DATALOADERS --- print("Loading datasets...") train_dataset = TimeStepDataset(train_pt_path) val_timestep_dataset = TimeStepDataset(val_pt_path) # For single-step validation test_trajectory_dataset = TrajectoryDataset(val_pt_path) # For rollout evaluation train_loader = DataLoader(train_dataset, batch_size=hparams['batch_size'], shuffle=True) val_timestep_loader = DataLoader(val_timestep_dataset, batch_size=hparams['batch_size'], shuffle=False) test_trajectory_loader = DataLoader(test_trajectory_dataset, batch_size=1, shuffle=False) # --- COMPUTE NORMALIZATION STATISTICS FROM TRAINING DATA --- def compute_normalization_stats(train_dataset): """Compute normalization statistics from training dataset""" coords_list = [] vel_list = [] inlet_vel_list = [] print("Computing normalization statistics from training data...") for sample in train_dataset: coords_list.append(sample['coordinates']) vel_list.append(sample['current_velocities']) # Handle inlet velocity (it's in meta_info and may be tensor or scalar) inlet_vel = sample['meta_info']['velocity'] if torch.is_tensor(inlet_vel): inlet_vel_list.append(inlet_vel.item()) else: inlet_vel_list.append(float(inlet_vel)) # Stack and compute statistics coords_all = torch.stack(coords_list) # [num_samples, num_nodes, 3] vel_all = torch.stack(vel_list) # [num_samples, num_nodes, 3] inlet_vel_all = torch.tensor(inlet_vel_list) # [num_samples] stats = { 'coords_mean': coords_all.mean(dim=[0, 1]), # Mean across samples and nodes 'coords_std': coords_all.std(dim=[0, 1]), 'vel_mean': vel_all.mean(dim=[0, 1]), 'vel_std': vel_all.std(dim=[0, 1]), 'inlet_vel_mean': inlet_vel_all.mean(), 'inlet_vel_std': inlet_vel_all.std() } print(f"Computed stats - Coords mean: {stats['coords_mean']}, std: {stats['coords_std']}") print(f"Velocities mean: {stats['vel_mean']}, std: {stats['vel_std']}") print(f"Inlet vel mean: {stats['inlet_vel_mean']:.6f}, std: {stats['inlet_vel_std']:.6f}") return stats # Compute normalization statistics norm_stats = compute_normalization_stats(train_dataset) coords_mean = norm_stats['coords_mean'].to(device) coords_std = norm_stats['coords_std'].to(device) vel_mean = norm_stats['vel_mean'].to(device) vel_std = norm_stats['vel_std'].to(device) inlet_vel_mean = norm_stats['inlet_vel_mean'].to(device) inlet_vel_std = norm_stats['inlet_vel_std'].to(device) epsilon = 1e-8 # Small constant to prevent division by zero # --- MODEL, OPTIMIZER, SCHEDULER SETUP --- model = Model(in_dim=hparams['in_dim'], out_dim=hparams['out_dim'], n_hidden=hparams['n_hidden'], n_layers=hparams['n_layers'], n_head=hparams['n_head'], slice_num=hparams['slice_num']).to(device) optimizer = torch.optim.Adam(model.parameters(), lr=hparams['lr']) scheduler = torch.optim.lr_scheduler.StepLR(optimizer, step_size=50, gamma=0.9) criterion = nn.MSELoss() # Initialize training variables start_epoch = 0 best_val_loss = float('inf') # Check for existing checkpoint to resume training latest_checkpoint_path = os.path.join(output_dir, 'checkpoint_latest.pth') if os.path.exists(latest_checkpoint_path): print(f"Found existing checkpoint: {latest_checkpoint_path}") try: start_epoch, last_loss, loaded_norm_stats = load_checkpoint( model, optimizer, scheduler, latest_checkpoint_path ) if loaded_norm_stats is not None: norm_stats = loaded_norm_stats # Update the normalization tensors coords_mean = norm_stats['coords_mean'].to(device) coords_std = norm_stats['coords_std'].to(device) vel_mean = norm_stats['vel_mean'].to(device) vel_std = norm_stats['vel_std'].to(device) inlet_vel_mean = norm_stats['inlet_vel_mean'].to(device) inlet_vel_std = norm_stats['inlet_vel_std'].to(device) print("Loaded normalization statistics from checkpoint.") print(f"Resuming training from epoch {start_epoch}") best_val_loss = last_loss except Exception as e: print(f"Error loading checkpoint: {e}") print("Starting fresh training...") start_epoch = 0 best_val_loss = float('inf') print(f"Starting training from epoch {start_epoch} to {hparams['nb_epochs']}") print("="*60) train_loss_history = [] val_loss_history = [] lr_history = [] val_epochs = [] # --- TRAINING LOOP --- for epoch in range(start_epoch, hparams['nb_epochs']): epoch_start_time = time.time() model.train() total_train_loss = 0.0 for batch_idx, batch in enumerate(train_loader): coordinates = batch['coordinates'].to(device) node_type = batch['node_type'].to(device) current_velocities = batch['current_velocities'].to(device) target_velocities = batch['target_velocities'].to(device) inlet_velocities = batch['meta_info']['velocity'] if torch.is_tensor(inlet_velocities): inlet_vel_tensor = inlet_velocities.clone().detach().float().to(device) else: inlet_vel_tensor = torch.tensor(inlet_velocities, dtype=torch.float32).to(device) # --- NORMALIZE FEATURES --- norm_coords = (coordinates - coords_mean) / (coords_std + epsilon) norm_current_vel = (current_velocities - vel_mean) / (vel_std + epsilon) norm_target_vel = (target_velocities - vel_mean) / (vel_std + epsilon) norm_inlet_vel = (inlet_vel_tensor - inlet_vel_mean) / (inlet_vel_std + epsilon) batch_size, num_nodes, _ = coordinates.shape inlet_vel_feature = norm_inlet_vel.view(batch_size, 1, 1).expand(batch_size, num_nodes, 1) # Input: [normalized coordinates, node_type, normalized velocities, normalized inlet_velocity] input_features = torch.cat([norm_coords, node_type, norm_current_vel, inlet_vel_feature], dim=-1) optimizer.zero_grad() predicted_normalized_velocities = model(input_features) # Apply wall masking mask = create_wall_mask(node_type) loss = criterion(predicted_normalized_velocities * mask, norm_target_vel * mask) loss.backward() optimizer.step() total_train_loss += loss.item() # Progress update every 50 batches if batch_idx % 50 == 0: print(f"Epoch {epoch+1}/{hparams['nb_epochs']} | Batch {batch_idx+1}/{len(train_loader)} | Loss: {loss.item():.6f}") scheduler.step() lr_history.append(optimizer.param_groups[0]['lr']) epoch_time = time.time() - epoch_start_time avg_train_loss = total_train_loss / len(train_loader) train_loss_history.append(avg_train_loss) print(f"Epoch {epoch+1}/{hparams['nb_epochs']} completed | Avg Train Loss: {avg_train_loss:.6f} | Time: {epoch_time:.2f}s") # --- PERIODIC EVALUATION --- if (epoch + 1) % hparams['eval_freq'] == 0 or epoch == hparams['nb_epochs'] - 1: print(f"Epoch {epoch+1}/{hparams['nb_epochs']} | Train Loss: {avg_train_loss:.6f}") # Rollout evaluation print(" Running rollout evaluation...") rollout_results = evaluate_rollout(model, test_trajectory_loader, device, norm_stats) # Calculate loss from rollout total_rollout_mse = 0.0 for result in rollout_results: # Move tensors to the correct device pred_traj = result['predicted_trajectory'].to(device) gt_traj = result['ground_truth_trajectory'].to(device) node_type = result['node_type'].to(device) # Create a mask to ignore wall nodes mask = create_wall_mask(node_type).unsqueeze(0) # Add time dim for broadcasting # Calculate masked MSE loss = criterion(pred_traj * mask, gt_traj * mask) total_rollout_mse += loss.item() avg_rollout_mse = total_rollout_mse / len(rollout_results) val_loss = avg_rollout_mse val_loss_history.append(val_loss) val_epochs.append(epoch + 1) print(f" Validation Rollout MSE: {val_loss:.6f}") # Save rollout results rollout_path = os.path.join(output_dir, f"rollout_results_epoch_{epoch+1}.npy") np.save(rollout_path, rollout_results, allow_pickle=True) # allow_pickle is good practice for np.save with dicts print(f" -> Saved rollout results to {rollout_path}") # Save best model based on rollout loss if val_loss < best_val_loss: best_val_loss = val_loss best_model_path = os.path.join(output_dir, 'best_model.pth') torch.save(model.state_dict(), best_model_path) print(f" -> New best model saved with validation loss: {best_val_loss:.6f}") # --- PERIODIC CHECKPOINTING --- if (epoch + 1) % hparams['checkpoint_freq'] == 0: # Use validation loss if available, otherwise use training loss checkpoint_loss = val_loss if 'val_loss' in locals() else avg_train_loss checkpoint_path = os.path.join(output_dir, f'checkpoint_epoch_{epoch+1}.pth') save_checkpoint(model, optimizer, scheduler, epoch + 1, checkpoint_loss, checkpoint_path, norm_stats) # --- SAVE LATEST CHECKPOINT --- save_checkpoint(model, optimizer, scheduler, hparams['nb_epochs'], best_val_loss, os.path.join(output_dir, 'checkpoint_latest.pth'), norm_stats) print("="*60) print("Training complete.") print(f"Best validation loss: {best_val_loss:.6f}") # --- PLOTTING AND SAVING LOSS HISTORY --- plt.figure(figsize=(10, 5)) plt.plot(train_loss_history, label='Training Loss') plt.plot(val_epochs, val_loss_history, 'o-', label='Validation Loss') plt.title('Training and Validation Loss Over Epochs') plt.xlabel('Epoch') plt.ylabel('Loss (MSE)') plt.legend() plt.grid(True) plt.savefig(os.path.join(output_dir, 'training_loss_plot.png')) print(f"Loss plot saved to {os.path.join(output_dir, 'training_loss_plot.png')}") loss_data = { 'train_loss_history': train_loss_history, 'val_loss_history': val_loss_history, 'val_epochs': val_epochs, 'lr_history': lr_history, 'best_val_loss': best_val_loss } with open(os.path.join(output_dir, 'loss_history.json'), 'w') as f: json.dump(loss_data, f, indent=4) print(f"Loss history saved to {os.path.join(output_dir, 'loss_history.json')}") script_end_time = time.time() elapsed_time_seconds = script_end_time - script_start_time print("="*60) print(f"Total script execution time: {elapsed_time_seconds / 60:.2f} minutes ({elapsed_time_seconds:.2f} seconds)") if __name__ == '__main__': main()