tensorboard

# TensorBoard: Visualization Toolkit for ML ## When to Use This Skill Use TensorBoard when you need to: - **Visualize training metrics** like loss and accuracy over time - **Debug models** with histograms and distributions - **Compare experiments** across multiple runs - **Visualize model graphs** and architecture - **Project embeddings** to lower dimensions (t-SNE, PCA) - **Track hyperparameter** experiments - **Profile performance** and identify bottlenecks - **Visualize images and text** during training **Users**: 20M+ downloads/year | **GitHub Stars**: 27k+ | **License**: Apache 2.0 ## Installation ```bash # Install TensorBoard pip install tensorboard # PyTorch integration pip install torch torchvision tensorboard # TensorFlow integration (TensorBoard included) pip install tensorflow # Launch TensorBoard tensorboard --logdir=runs # Access at http://localhost:6006 ``` ## Quick Start ### PyTorch ```python from torch.utils.tensorboard import SummaryWriter # Create writer writer = SummaryWriter('runs/experiment_1') # Training loop for epoch in range(10): train_loss = train_epoch() val_acc = validate() # Log metrics writer.add_scalar('Loss/train', train_loss, epoch) writer.add_scalar('Accuracy/val', val_acc, epoch) # Close writer writer.close() # Launch: tensorboard --logdir=runs ``` ### TensorFlow/Keras ```python import tensorflow as tf # Create callback tensorboard_callback = tf.keras.callbacks.TensorBoard( log_dir='logs/fit', histogram_freq=1 ) # Train model model.fit( x_train, y_train, epochs=10, validation_data=(x_val, y_val), callbacks=[tensorboard_callback] ) # Launch: tensorboard --logdir=logs ``` ## Core Concepts ### 1. SummaryWriter (PyTorch) ```python from torch.utils.tensorboard import SummaryWriter # Default directory: runs/CURRENT_DATETIME writer = SummaryWriter() # Custom directory writer = SummaryWriter('runs/experiment_1') # Custom comment (appended to default directory) writer = SummaryWriter(comment='baseline') # Log data writer.add_scalar('Loss/train', 0.5, step=0) writer.add_scalar('Loss/train', 0.3, step=1) # Flush and close writer.flush() writer.close() ``` ### 2. Logging Scalars ```python # PyTorch from torch.utils.tensorboard import SummaryWriter writer = SummaryWriter() for epoch in range(100): train_loss = train() val_loss = validate() # Log individual metrics writer.add_scalar('Loss/train', train_loss, epoch) writer.add_scalar('Loss/val', val_loss, epoch) writer.add_scalar('Accuracy/train', train_acc, epoch) writer.add_scalar('Accuracy/val', val_acc, epoch) # Learning rate lr = optimizer.param_groups[0]['lr'] writer.add_scalar('Learning_rate', lr, epoch) writer.close() ``` ```python # TensorFlow import tensorflow as tf train_summary_writer = tf.summary.create_file_writer('logs/train') val_summary_writer = tf.summary.create_file_writer('logs/val') for epoch in range(100): with train_summary_writer.as_default(): tf.summary.scalar('loss', train_loss, step=epoch) tf.summary.scalar('accuracy', train_acc, step=epoch) with val_summary_writer.as_default(): tf.summary.scalar('loss', val_loss, step=epoch) tf.summary.scalar('accuracy', val_acc, step=epoch) ``` ### 3. Logging Multiple Scalars ```python # PyTorch: Group related metrics writer.add_scalars('Loss', { 'train': train_loss, 'validation': val_loss, 'test': test_loss }, epoch) writer.add_scalars('Metrics', { 'accuracy': accuracy, 'precision': precision, 'recall': recall, 'f1': f1_score }, epoch) ``` ### 4. Logging Images ```python # PyTorch import torch from torchvision.utils import make_grid # Single image writer.add_image('Input/sample', img_tensor, epoch) # Multiple images as grid img_grid = make_grid(images[:64], nrow=8) writer.add_image('Batch/inputs', img_grid, epoch) # Predictions visualization pred_grid = make_grid(predictions[:16], nrow=4) writer.add_image('Predictions', pred_grid, epoch) ``` ```python # TensorFlow import tensorflow as tf with file_writer.as_default(): # Encode images as PNG tf.summary.image('Training samples', images, step=epoch, max_outputs=25) ``` ### 5. Logging Histograms ```python # PyTorch: Track weight distributions for name, param in model.named_parameters(): writer.add_histogram(name, param, epoch) # Track gradients if param.grad is not None: writer.add_histogram(f'{name}.grad', param.grad, epoch) # Track activations writer.add_histogram('Activations/relu1', activations, epoch) ``` ```python # TensorFlow with file_writer.as_default(): tf.summary.histogram('weights/layer1', layer1.kernel, step=epoch) tf.summary.histogram('activations/relu1', activations, step=epoch) ``` ### 6. Logging Model Graph ```python # PyTorch import torch model = MyModel() dummy_input = torch.randn(1, 3, 224, 224) writer.add_graph(model, dummy_input) writer.close() ``` ```python # TensorFlow (automatic with Keras) tensorboard_callback = tf.keras.callbacks.TensorBoard( log_dir='logs', write_graph=True ) model.fit(x, y, callbacks=[tensorboard_callback]) ``` ## Advanced Features ### Embedding Projector Visualize high-dimensional data (embeddings, features) in 2D/3D. ```python import torch from torch.utils.tensorboard import SummaryWriter # Get embeddings (e.g., word embeddings, image features) embeddings = model.get_embeddings(data) # Shape: (N, embedding_dim) # Metadata (labels for each point) metadata = ['class_1', 'class_2', 'class_1', ...] # Images (optional, for image embeddings) label_images = torch.stack([img1, img2, img3, ...]) # Log to TensorBoard writer.add_embedding( embeddings, metadata=metadata, label_img=label_images, global_step=epoch ) ``` **In TensorBoard:** - Navigate to "Projector" tab - Choose PCA, t-SNE, or UMAP visualization - Search, filter, and explore clusters ### Hyperparameter Tuning ```python from torch.utils.tensorboard import SummaryWriter # Try different hyperparameters for lr in [0.001, 0.01, 0.1]: for batch_size in [16, 32, 64]: # Create unique run directory writer = SummaryWriter(f'runs/lr{lr}_bs{batch_size}') # Log hyperparameters writer.add_hparams( {'lr': lr, 'batch_size': batch_size}, {'hparam/accuracy': final_acc, 'hparam/loss': final_loss} ) # Train and log for epoch in range(10): loss = train(lr, batch_size) writer.add_scalar('Loss/train', loss, epoch) writer.close() # Compare in TensorBoard's "HParams" tab ``` ### Text Logging ```python # PyTorch: Log text (e.g., model predictions, summaries) writer.add_text('Predictions', f'Epoch {epoch}: {predictions}', epoch) writer.add_text('Config', str(config), 0) # Log markdown tables markdown_table = """ | Metric | Value | |--------|-------| | Accuracy | 0.95 | | F1 Score | 0.93 | """ writer.add_text('Results', markdown_table, epoch) ``` ### PR Curves Precision-Recall curves for classification. ```python from torch.utils.tensorboard import SummaryWriter # Get predictions and labels predictions = model(test_data) # Shape: (N, num_classes) labels = test_labels # Shape: (N,) # Log PR curve for each class for i in range(num_classes): writer.add_pr_curve( f'PR_curve/class_{i}', labels == i, predictions[:, i], global_step=epoch ) ``` ## Integration Examples ### PyTorch Training Loop ```python import torch import torch.nn as nn from torch.utils.tensorboard import SummaryWriter # Setup writer = SummaryWriter('runs/resnet_experiment') model = ResNet50() optimizer = torch.optim.Adam(model.parameters(), lr=0.001) criterion = nn.CrossEntropyLoss() # Log model graph dummy_input = torch.randn(1, 3, 224, 224) writer.add_graph(model, dummy_input) # Training loop for epoch in range(50): model.train() train_loss = 0.0 train_correct = 0 for batch_idx, (data, target) in enumerate(train_loader): optimizer.zero_grad() output = model(data) loss = criterion(output, target) loss.backward() optimizer.step() train_loss += loss.item() pred = output.argmax(dim=1) train_correct += pred.eq(target).sum().item() # Log batch metrics (every 100 batches) if batch_idx % 100 == 0: global_step = epoch * len(train_loader) + batch_idx writer.add_scalar('Loss/train_batch', loss.item(), global_step) # Epoch metrics train_loss /= len(train_loader) train_acc = train_correct / len(train_loader.dataset) # Validation model.eval() val_loss = 0.0 val_correct = 0 with torch.no_grad(): for data, target in val_loader: output = model(data) val_loss += criterion(output, target).item() pred = output.argmax(dim=1) val_correct += pred.eq(target).sum().item() val_loss /= len(val_loader) val_acc = val_correct / len(val_loader.dataset) # Log epoch metrics writer.add_scalars('Loss', {'train': train_loss, 'val': val_loss}, epoch) writer.add_scalars('Accuracy', {'train': train_acc, 'val': val_acc}, epoch) # Log learning rate writer.add_scalar('Learning_rate', optimizer.param_groups[0]['lr'], epoch) # Log histograms (every 5 epochs) if epoch % 5 == 0: for name, param in model.named_parameters(): writer.add_histogram(name, param, epoch) # Log sample predictions if epoch % 10 == 0: sample_images = data[:8] writer.add_image('Sample_inputs', make_grid(sample_images), epoch) writer.close() ``` ### TensorFlow/Keras Training ```python import tensorflow as tf # Define model model = tf.keras.models.Sequential([ tf.keras.layers.Conv2D(32, 3, activation='relu', input_shape=(28, 28, 1)), tf.keras.layers.MaxPooling2D(), tf.keras.layers.Flatten(), tf.keras.layers.Dense(128, activation='relu'), tf.keras.layers.Dense(10, activation='softmax') ]) model.compile( optimizer='adam', loss='sparse_categorical_crossentropy', metrics=['accuracy'] ) # TensorBoard callback tensorboard_callback = tf.keras.callbacks.TensorBoard( log_dir='logs/fit', histogram_freq=1, # Log histograms every epoch write_graph=True, # Visualize model graph write_images=True, # Visualize weights as images update_freq='epoch', # Log metrics every epoch profile_batch='500,520', # Profile batches 500-520 embeddings_freq=1 # Log embeddings every epoch ) # Train