import torch from transformers import BertTokenizer, BertForMaskedLM import matplotlib.pyplot as plt from sklearn.manifold import TSNE import numpy as np from mpl_toolkits.mplot3d import Axes3D # Load a pre-trained model and tokenizer model_name = 'bert-base-uncased' tokenizer = BertTokenizer.from_pretrained(model_name) model = BertForMaskedLM.from_pretrained(model_name) # Example input text text = "The quick brown fox jumps over the lazy dog" # Tokenize the input text inputs = tokenizer(text, return_tensors="pt") input_ids = inputs['input_ids'] # Get attention weights by running the model with torch.no_grad(): outputs = model(input_ids, output_attentions=True) # Extract the attention weights (size: [num_layers, num_heads, seq_len, seq_len]) attention_weights = outputs.attentions # Select a specific layer and attention head layer_idx = 0 # First layer head_idx = 0 # First attention head # Get the attention matrix for this layer and head attention_matrix = attention_weights[layer_idx][0][head_idx].cpu().numpy() # Use t-SNE to reduce the dimensionality of the attention matrix (embedding space) # Attention matrix shape: [seq_len, seq_len], so we reduce each row (which corresponds to a token's attention distribution) tsne = TSNE(n_components=3, random_state=42, perplexity=5) # Set a lower perplexity value reduced_attention = tsne.fit_transform(attention_matrix) # Plotting the reduced attention embeddings in 3D fig = plt.figure(figsize=(12, 10)) ax = fig.add_subplot(111, projection='3d') # Plot the reduced attention in 3D ax.scatter(reduced_attention[:, 0], reduced_attention[:, 1], reduced_attention[:, 2]) # Annotate the tokens in the scatter plot tokens = tokenizer.convert_ids_to_tokens(input_ids[0]) for i, token in enumerate(tokens): ax.text(reduced_attention[i, 0], reduced_attention[i, 1], reduced_attention[i, 2], token, fontsize=12, ha='center') # Set plot labels ax.set_title(f"3D t-SNE Visualization of Attention - Layer {layer_idx+1}, Head {head_idx+1}") ax.set_xlabel("t-SNE Dimension 1") ax.set_ylabel("t-SNE Dimension 2") ax.set_zlabel("t-SNE Dimension 3") plt.show()