import argparse import math import os import torch import torch.nn as nn import torch.nn.functional as F import torch.optim as optim from torch.utils.data import DataLoader import copy from torch.optim.lr_scheduler import CosineAnnealingLR from torch.cuda.amp import autocast, GradScaler from datasets import load_dataset from transformers import AutoTokenizer from typing import List, Tuple device = torch.device('cuda' if torch.cuda.is_available() else 'cpu') def parse_args(): parser = argparse.ArgumentParser(description='Train or Inference with World Model and Tree of Thought.') parser.add_argument('--model_name', type=str, default='gpt2', help='Pretrained model name or path') parser.add_argument('--dataset_name', type=str, default='wikitext', help='Dataset name from HuggingFace Datasets') parser.add_argument('--dataset_config', type=str, default='wikitext-2-raw-v1', help='Dataset configuration name') parser.add_argument('--batch_size', type=int, default=4, help='Batch size') parser.add_argument('--num_epochs', type=int, default=3, help='Number of epochs') parser.add_argument('--max_length', type=int, default=128, help='Maximum sequence length') parser.add_argument('--mcts_iterations', type=int, default=3, help='Number of MCTS Iterations') parser.add_argument('--mcts_exploration_constant', type=float, default=1.414, help='Exploration constant for MCTS') parser.add_argument('--accumulation_steps', type=int, default=4, help='Gradient accumulation steps') parser.add_argument('--learning_rate', type=float, default=1e-4, help='Learning rate') parser.add_argument('--weight_decay', type=float, default=1e-2, help='Weight decay') parser.add_argument('--alpha', type=float, default=0.1, help='Entropy regularization weight') parser.add_argument('--beta', type=float, default=0.1, help='Variance regularization weight') parser.add_argument('--max_grad_norm', type=float, default=1.0, help='Max gradient norm for clipping') parser.add_argument('--save_dir', type=str, default='./models', help='Directory to save the models') parser.add_argument('--temperature', type=float, default=1.0, help='Temperature parameter for entropy and variance') parser.add_argument('--mode', type=str, choices=['train', 'inference'], default='inference', help='Mode: train or inference') parser.add_argument('--inference_mode', type=str, choices=['world_model', 'without_world_model', 'world_model_tree_of_thought'], default='world_model_tree_of_thought', help='Inference mode') parser.add_argument('--query', type=str, default='', help='Input query for inference') parser.add_argument('--train_mode', type=str, choices=['world_model', 'language_model'], default='world_model', help='Train world model or language model only') parser.add_argument('--beam_size', type=int, default=5, help='Beam size for beam search') parser.add_argument('--n_tokens_predict', type=int, default=3, help='Number of tokens to predict at each step') parser.add_argument('--load_model', type=str, default=None, help='Path to load saved model. If not provided, a new model will be initialized.') # Use parse_known_args to ignore unknown arguments args, unknown = parser.parse_known_args() return args def load_data(args, tokenizer): # Load the dataset dataset = load_dataset(args.dataset_name, args.dataset_config) # Ensure the tokenizer has a padding token if tokenizer.pad_token is None: tokenizer.pad_token = tokenizer.eos_token def tokenize_function(examples): return tokenizer(examples['text'], truncation=True, max_length=args.max_length) tokenized_datasets = dataset.map( tokenize_function, batched=True, num_proc=4, remove_columns=dataset['train'].column_names, ) # Build inputs and labels for language modeling block_size = args.max_length def group_texts(examples): # Concatenate all texts concatenated_examples = {k: sum(examples[k], []) for k in examples.keys()} total_length = len(concatenated_examples['input_ids']) # We drop the small remainder total_length = (total_length // block_size) * block_size # Split by chunks of block_size result = { k: [t[i : i + block_size] for i in range(0, total_length, block_size)] for k, t in concatenated_examples.items() } result['labels'] = result['input_ids'].copy() return result lm_datasets = tokenized_datasets.map( group_texts, batched=True, num_proc=4, ) # Create DataLoader train_dataset = lm_datasets['train'] eval_dataset = lm_datasets['validation'] if 'validation' in lm_datasets else lm_datasets['test'] def data_collator(data): return { 'input_ids': torch.tensor([f['input_ids'] for f in data], dtype=torch.long), 'labels': torch.tensor([f['labels'] for f in data], dtype=torch.long) } train_loader = DataLoader( train_dataset, shuffle=True, batch_size=args.batch_size, collate_fn=data_collator, pin_memory=True, # Speeds up transfer to GPU num_workers=4 ) eval_loader = DataLoader( eval_dataset, shuffle=False, batch_size=args.batch_size, collate_fn=data_collator, pin_memory=True, num_workers=4 ) return train_loader, eval_loader def save_all_models(transformer_model, representation_network, dynamics_network, prediction_network, action_encoder, save_dir, epoch): """ Save all models to the specified directory. Args: transformer_model (nn.Module): Transformer model. representation_network (nn.Module): Representation network. dynamics_network (nn.Module): Dynamics network. prediction_network (nn.Module): Prediction network. action_encoder (nn.Module): Action encoder. save_dir (str): Directory to save the models. epoch (int): Current epoch number. """ os.makedirs(save_dir, exist_ok=True) torch.save(transformer_model.state_dict(), os.path.join(save_dir, f'transformer_model_epoch_{epoch}.pt')) torch.save(representation_network.state_dict(), os.path.join(save_dir, f'representation_network_epoch_{epoch}.pt')) torch.save(dynamics_network.state_dict(), os.path.join(save_dir, f'dynamics_network_epoch_{epoch}.pt')) torch.save(prediction_network.state_dict(), os.path.join(save_dir, f'prediction_network_epoch_{epoch}.pt')) torch.save(action_encoder.state_dict(), os.path.join(save_dir, f'action_encoder_epoch_{epoch}.pt')) print(f"All models saved for epoch {epoch}.") class RotaryPositionalEncoding(nn.Module): def __init__(self, d_model): super(RotaryPositionalEncoding, self).__init__() inv_freq = 1.0 / (10000 ** (torch.arange(0, d_model, 2).float() / d_model)) self.register_buffer('inv_freq', inv_freq) def forward(self, x): seq_len, batch_size, _ = x.size() t = torch.arange(seq_len, device=x.device).type_as(self.inv_freq) sinusoid_inp = torch.einsum("i,j->ij", t, self.inv_freq) sin = sinusoid_inp.sin().unsqueeze(1) # (seq_len, 1, d_model/2) cos = sinusoid_inp.cos().unsqueeze(1) # (seq_len, 1, d_model/2) x1 = x[..., 0::2] x2 = x[..., 1::2] # Apply rotation x_rotated = torch.zeros_like(x) x_rotated[..., 0::2] = x1 * cos - x2 * sin x_rotated[..., 1::2] = x1 * sin + x2 * cos return x_rotated class MultiHeadAttention(nn.Module): def __init__(self, d_model, num_heads): super(MultiHeadAttention, self).__init__() assert d_model % num_heads == 0, "d_model must be divisible by num_heads" self.d_k = d_model // num_heads self.num_heads = num_heads self.linear_q = nn.Linear(d_model, d_model) self.linear_k = nn.Linear(d_model, d_model) self.linear_v = nn.Linear(d_model, d_model) self.linear_out = nn.Linear(d_model, d_model) def forward(self, query, key, value, mask=None): batch_size = query.size(0) query = self.linear_q(query).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2) key = self.linear_k(key).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2) value = self.linear_v(value).view(batch_size, -1, self.num_heads, self.d_k).transpose(1, 2) scores = torch.matmul(query, key.transpose(-2, -1)) / math.sqrt(self.d_k) if mask is not None: scores = scores.masked_fill(mask == 0, -1e4) attn = F.softmax(scores, dim=-1) output = torch.matmul(attn, value) output = output.transpose(1, 2).contiguous().view(batch_size, -1, self.num_heads * self.d_k) return self.linear_out(output) class MoE(nn.Module): def __init__(self, d_model, num_experts, d_ff, top_k=2, dropout=0.1): super(MoE, self).__init__() self.num_experts = num_experts self.top_k = top_k self.experts = nn.ModuleList([ nn.Sequential( nn.Linear(d_model, d_ff), nn.GELU() if i % 2 == 0 else nn.SiLU(), nn.Linear(d_ff, d_model) ) for i in range(num_experts) ]) self.gate = nn.Linear(d_model, num_experts) self.dropout = nn.Dropout(dropout) def forward(self, x): batch_size, seq_len, d_model = x.size() # Compute gating scores gate_scores = self.gate(x) # (batch_size, seq_len, num_experts) top_k_scores, top_k_indices = torch.topk(gate_scores, self.top_k, dim=-1) # (batch_size, seq_len, top_k) top_k_scores = F.softmax(top_k_scores, dim=-1) # (batch_size, seq_len, top_k) # Initialize output output = torch.zeros_like(x) # Flatten batch and sequence dimensions x_flat = x.view(-1, d_model) # (batch_size * seq_len, d_model) output_flat = output.view(-1, d_model) top_k_indices_flat = top_k_indices.view(-1, self.top_k) # (batch_size * seq_len, top_k) top_k_scores_flat = top_k_scores.view(-1, self.top_k) # (batch_size * seq_len, top_k) for k in range(self.top_k): expert_idx_flat = top_k_indices_flat[:, k] # (batch_size * seq_len) expert_scores_flat = top_k_scores_flat[:, k] # (batch_size * seq_len) for e in range(self.num_experts): mask = (expert_idx_flat == e) # Boolean mask if mask.any(): x_masked = x_flat[mask] # Select tokens for expert e expert_output = self.experts[e](x_masked) # Apply expert e output_flat[mask] += expert_scores_flat[mask].unsqueeze(-1) * expert_output output = output_flat.view(batch_size, seq_len, d_model) return self.dropout(output) class TransformerBlock(nn.Module): def __init__(self, d_model, num_heads, d_ff, num_experts, dropout=0.1, top_k=2): super(TransformerBlock, self).__init__() self.self_attention = MultiHeadAttention(d_model, num_heads) self.norm1 = nn.LayerNorm(d_model) self.cross_attention = MultiHeadAttention(d_model, num_heads) self.norm2 = nn.LayerNorm(d_model) self.moe = MoE(d_model, num_experts, d_ff, top_k, dropout) self.norm3 = nn.LayerNorm(d_model) def forward(self, x, mask=None, enc_output=None, enc_mask=None): # Self-attention attn_output = self.self_attention(x, x, x, mask) x = self.norm1(x + attn_output) # Cross-attention (only in decoder) if enc_output is not None: cross_attn_output = self.cross_attention(x, enc_output, enc_output, enc_mask) x = self.norm2(x + cross_attn_output) # Feedforward/MoE moe_output = self.moe(x) return self.norm3(x + moe_output) class Transformer(nn.Module): def __init__(self, input_dim, d_model, num_heads, num_layers, d_ff, num_experts, output_dim, dropout=0.1, top_k=2): super(Transformer, self).__init__() self.embedding = nn.Embedding(input_dim, d_model, padding_idx=input_dim - 1) self.rotary_positional_encoding = RotaryPositionalEncoding(d_model) self.encoder_layers = nn.ModuleList( [TransformerBlock(d_model, num_heads, d_ff, num_experts, dropout, top_k) for _ in range(num_layers)] ) self.decoder_layers = nn.ModuleList( [TransformerBlock(d_model, num_heads, d_ff, num_experts, dropout, top_k) for _ in range(num_layers)] ) self.output_layer = nn.Linear(d_model, output_dim) self.d_model = d_model def forward(self, src, tgt, src_mask=None, tgt_mask=None): # Encoder src = self.embedding(src) * math.sqrt(self.d_model) src = src.transpose(0, 1) # (batch_size, seq_len, d_model) -> (seq_len, batch_size, d_model) src = self.rotary_positional_encoding(src) src = src.transpose(0, 1) # (seq_len, batch_size, d_model) -> (batch_size, seq_len, d_model) for layer in self.encoder_layers: src = layer(src, src_mask) # Decoder tgt = self.embedding(tgt) * math.sqrt(self.d_model) tgt = tgt.transpose(0, 1) tgt = self.rotary_positional_encoding(tgt) tgt = tgt.transpose(0, 1) for layer in self.decoder_layers: tgt = layer(tgt, tgt_mask, src, src_mask) output = self.output_layer(tgt) return output def generate_with_beam_search(self, src, tokenizer, beam_size=5, max_length=20, n_tokens_predict=3, temperature=1.0): """ Generate sequences using beam search with multi-token prediction. Args: src (torch.Tensor): Source input tensor of shape (batch_size, seq_len) tokenizer: Tokenizer to access special tokens beam_size (int): Size of the beam for beam search max_length (int): Maximum length of the generated sequence n_tokens_predict (int): Number of tokens to predict at each step temperature (float): Temperature parameter for softmax Returns: List[Tuple[torch.Tensor, float]]: List of (sequence, score) tuples """ batch_size = src.size(0) device = src.device vocab_size = self.output_layer.out_features # Encode the source src_enc = self.encode(src) # Initialize beam beam = [(torch.full((batch_size, 1), tokenizer.bos_token_id, dtype=torch.long, device=device), 0.0, # log probability torch.zeros(batch_size, device=device), # cumulative entropy torch.zeros(batch_size, device=device))] # cumulative variance for _ in range(max_length // n_tokens_predict): all_candidates = [] for seq, score, cum_entropy, cum_variance in beam: if seq[:, -1].item() == tokenizer.eos_token_id: all_candidates.append((seq, score, cum_entropy, cum_variance)) continue # Predict next n tokens logits = self.predict_next_n_tokens(src_enc, seq, n_tokens_predict) # Calculate probabilities, entropy, and variance probs = F.softmax(logits / temperature, dim=-1) entropy = -torch.sum(probs * torch.log(probs + 1e-9), dim=-1) variance = torch.var(probs, dim=-1) # Sample top-k tokens for each position topk_probs, topk_indices = torch.topk(probs, k=beam_size, dim=-1) # Generate all possible continuations for i in range(beam_size ** n_tokens_predict): indices = [i // (beam_size ** j) % beam_size for j in range(n_tokens_predict)] new_tokens = topk_indices[:, range(n_tokens_predict), indices] new_seq = torch.cat([seq, new_tokens], dim=-1) new_score = score + torch.sum(torch.log(topk_probs[:, range(n_tokens_predict), indices])) new_entropy = cum_entropy + torch.sum(entropy[:, indices]) new_variance = cum_variance + torch.sum(variance[:, indices]) all_candidates.append((new_seq, new_score, new_entropy, new_variance)) # Select top beam_size candidates beam = sorted(all_candidates, key=lambda x: x[1] - 0.1 * x[2] + 0.05 * x[3], reverse=True)[:beam_size] # Stop if all beams have ended if all(seq[:, -1].item() == tokenizer.eos_token_id for seq, _, _, _ in beam): break return [(seq, score) for seq, score, _, _ in beam] def encode(self, src): src_emb = self.embedding(src) * math.sqrt(self.d_model) src_emb = src_emb.transpose(0, 1) src_emb = self.rotary_positional_encoding(src_emb) src_emb = src_emb.transpose(0, 1) src_enc = src_emb for layer in self.encoder_layers: src_enc = layer(src_enc) return src_enc def predict_next_n_tokens(self, src_enc, tgt_seq, n_tokens): tgt_emb = self.embedding(tgt_seq) * math.sqrt(self.d_model) tgt_emb = tgt_emb.transpose(0, 1) tgt_emb = self.rotary_positional_encoding(tgt_emb) tgt_emb = tgt_emb.transpose(0, 1) tgt_dec = tgt_emb for layer in self.decoder_layers: tgt_dec = layer(tgt_dec, None, src_enc, None) output = self.output_layer(tgt_dec[:, -1:]) return output.repeat(1, n_tokens, 1) # Objective Functions class InfoNCE_Loss(nn.Module): def __init__(self, temperature=0.07): super(InfoNCE_Loss, self).__init__() self.temperature = temperature self.cross_entropy = nn.CrossEntropyLoss() def forward(self, z_i, z_j): """ Args: z_i (torch.Tensor): Flattened representations from view i, shape (2n, embed_dim) z_j (torch.Tensor): Flattened representations from view j, shape (2n, embed_dim) Returns: torch.Tensor: InfoNCE loss """ n = z_i.size(0) z = torch.cat([z_i, z_j], dim=0) # Shape: (2n, embed_dim) z = F.normalize(z, dim=1) similarity_matrix = torch.matmul(z, z.T) # Shape: (2n, 2n) # Create a mask to exclude self-similarity mask = torch.eye(2 * n, device=z.device, dtype=torch.bool) similarity_matrix = similarity_matrix.masked_fill(mask, -1e4) # Use a manageable negative value # Create labels for contrastive learning labels = torch.arange(n, device=z.device) labels = torch.cat([labels + n, labels], dim=0) # Shape: (2n,) # Apply temperature scaling similarity_matrix /= self.temperature # Compute cross-entropy loss loss = self.cross_entropy(similarity_matrix, labels) return loss class CovarianceRegularization(nn.Module): def __init__(self, lambda_reg=1e-3): super(CovarianceRegularization, self).__init__() self.lambda_reg = lambda_reg def forward(self, embeddings): """ Args: embeddings (torch.Tensor): Embedding tensor, shape (batch_size, embed_dim) Returns: torch.Tensor: Covariance regularization loss """ batch_size, embed_dim = embeddings.size() mean = embeddings.mean(dim=0) embeddings_centered = embeddings - mean cov = (embeddings_centered.T @ embeddings_centered) / (batch_size - 1) cov_loss = torch.sum(cov ** 2) - torch.sum(torch.diag(cov) ** 2) return self.lambda_reg * cov_loss class DynamicsPerformanceLoss(nn.Module): def __init__(self, lambda_var=1e-3): super(DynamicsPerformanceLoss, self).__init__() self.lambda_var = lambda_var def forward(self, true_next_state, predicted_next_state): """ Args: true_next_state (torch.Tensor): Ground truth next state, shape (batch_size, state_dim) predicted_next_state (torch.Tensor): Predicted next state, shape (batch_size, state_dim) Returns: torch.Tensor: Dynamics performance loss """ mse_loss = F.mse_loss(predicted_next_state, true_next_state) variance_loss = torch.var(predicted_next_state, dim=0).mean() return mse_loss + self.lambda_var * variance_loss class ThoughtConsistencyLoss(nn.Module): def __init__(self): super(ThoughtConsistencyLoss, self).__init__() def forward(self, true_next_state, perturbed_next_state): """ Args: true_next_state (torch.Tensor): Ground truth next state, shape (batch_size, state_dim) perturbed_next_state (torch.Tensor): Perturbed next state, shape (batch_size, state_dim) Returns: torch.Tensor: Thought-consistency loss """ return F.mse_loss(true_next_state, perturbed_next_state) class PolicyValueJointLoss(nn.Module): def __init__(self, lambda_value=0.5): super(PolicyValueJointLoss, self).__init__() self.lambda_value = lambda_value self.cross_entropy = nn.CrossEntropyLoss() self.mse_loss = nn.MSELoss() def forward(self, policy_logits, true_policy, value_pred, true_value): """ Args: policy_logits (torch.Tensor): Logits from the policy network, shape (batch_size * seq_len, num_actions) true_policy (torch.Tensor): Ground truth policy, shape (batch_size * seq_len, num_actions) value_pred (torch.Tensor): Predicted values, shape (batch_size * seq_len) true_value (torch.Tensor): Ground truth values, shape (batch_size * seq_len) Returns: torch.Tensor: Combined policy and value loss """ policy_logits = policy_logits.view(-1, policy_logits.size(-1)) true_policy = true_policy.view(-1, true_policy.size(-1)) value_pred = value_pred.view(-1) true_value = true_value.view(-1) policy_loss = self.cross_entropy(policy_logits, true_policy.argmax(dim=1)) value_loss = self.mse_loss(value_pred, true_value) return policy_loss + self.lambda_value * value_loss class ActionDiversityReward(nn.Module): def __init__(self, lambda_div=1e-3): super(ActionDiversityReward, self).__init__() self.lambda_div = lambda_div def forward(self, action_embeddings): """ Args: action_embeddings (torch.Tensor): Embeddings of actions, shape (batch_size, embed_dim) Returns: torch.Tensor: Action diversity loss """ similarity_matrix = F.cosine_similarity(action_embeddings.unsqueeze(1), action_embeddings.unsqueeze(0), dim=2) # Zero out self-similarity similarity_matrix = similarity_matrix - torch.eye(similarity_matrix.size(0)).to(action_embeddings.device) diversity_loss = torch.sum(similarity_matrix ** 2) return self.lambda_div * diversity_loss class ExpectedThoughtValueLoss(nn.Module): def __init__(self): super(ExpectedThoughtValueLoss, self).__init__() def forward(self, mcts_best_values): """ Args: mcts_best_values (torch.Tensor): Best values from MCTS, shape (batch_size) Returns: torch.Tensor: ETV loss """ return -mcts_best_values.mean() class ExplorationRegularization(nn.Module): def __init__(self, lambda_expl=1e-3): super(ExplorationRegularization, self).__init__() self.lambda_expl = lambda_expl def forward(self, visit_counts): """ Args: visit_counts (torch.Tensor): Visit counts for actions, shape (batch_size, num_actions) Returns: torch.Tensor: Exploration regularization loss """ reward = torch.sum(1.0 / (visit_counts + 1), dim=-1) return self.lambda_expl * reward.mean() class KL_DivergenceLoss(nn.Module): def __init__(self): super(KL_DivergenceLoss, self).__init__() def forward(self, old_policy, new_policy): """ Args: old_policy (torch.Tensor): Old policy probabilities, shape (batch_size, num_actions) new_policy (torch.Tensor): New policy probabilities, shape (batch_size, num_actions) Returns: torch.Tensor: KL divergence loss """ kl_div = F.kl_div(new_policy.log(), old_policy, reduction='batchmean') return kl_div # MuZero Components class ActionEncoder(nn.Module): def __init__(self, action_vocab_size, embed_dim): super(ActionEncoder, self).__init__() self.embedding = nn.Embedding(action_vocab_size, embed_dim) def forward(self, action_indices): """ Args: action_indices (torch.Tensor): Tensor of shape (batch_size, seq_len) Returns: torch.Tensor: Encoded actions of shape (batch_size, seq_len, embed_dim) """ return self.embedding(action_indices) class RepresentationNetwork(nn.Module): def __init__(self, vocab_dim, d_model, state_dim): super(RepresentationNetwork, self).__init__() self.proj = nn.Linear(vocab_dim, d_model) # Project from vocab_dim to d_model self.linear = nn.Linear(d_model, state_dim) # Project from d_model to state_dim self.norm = nn.LayerNorm(state_dim) def forward(self, transformer_output): """ Args: transformer_output (torch.Tensor): Shape (batch_size, seq_len, vocab_dim) Returns: torch.Tensor: Encoded state of shape (batch_size, seq_len, state_dim) """ # First project down from vocab_dim to d_model projected_output = self.proj(transformer_output) # Shape: (batch_size, seq_len, d_model) # Then project down from d_model to state_dim state = self.linear(projected_output) # Shape: (batch_size, seq_len, state_dim) state = self.norm(state) # Shape: (batch_size, seq_len, state_dim) return state class DynamicsNetwork(nn.Module): def __init__(self, state_dim, action_dim, hidden_dim): super(DynamicsNetwork, self).__init__() self.rms_norm = nn.LayerNorm(state_dim) self.fc1 = nn.Linear(state_dim + action_dim, hidden_dim) self.activation = nn.GELU() self.fc2 = nn.Linear(hidden_dim, state_dim) def forward(self, state, action): """ Args: state (torch.Tensor): Current state, shape (batch_size, state_dim) action (torch.Tensor): Action embedding, shape (batch_size, action_dim) Returns: torch.Tensor: Predicted next state, shape (batch_size, state_dim) """ norm_state = self.rms_norm(state) combined = torch.cat([norm_state, action], dim=-1) hidden = self.activation(self.fc1(combined)) next_state = self.fc2(hidden) return next_state class PredictionNetwork(nn.Module): def __init__(self, state_dim, action_vocab_size, value_dim): super(PredictionNetwork, self).__init__() self.state_dim = state_dim self.rms_norm = nn.LayerNorm(state_dim) self.policy_head = nn.Linear(state_dim, action_vocab_size) # Output size is action_vocab_size self.value_head = nn.Linear(state_dim, value_dim) def forward(self, state): """ Args: state (torch.Tensor): State representation, shape (batch_size, state_dim) Returns: Tuple[torch.Tensor, torch.Tensor]: Policy logits and value estimates """ norm_state = self.rms_norm(state) policy_logits = self.policy_head(norm_state) # Shape: (batch_size, action_vocab_size) value_estimates = self.value_head(norm_state).squeeze(-1) # Shape: (batch_size) return policy_logits, value_estimates class MCTSNode: __slots__ = [ 'state', 'parent', 'action', 'children', 'visit_count', 'value_sum', 'prior', 'cached_policy', 'cached_value', 'thought_node', 'entropy', 'variance' ] def __init__(self, state, thought_node, parent=None, action=None): self.state = state self.thought_node = thought_node self.parent = parent self.action = action self.children = {} self.visit_count = 0 self.value_sum = 0.0 self.prior = 0.0 self.cached_policy = None self.cached_value = None self.entropy = 0.0 self.variance = 0.0 def expand(self, priors): for child_thought_node in self.thought_node.children: action = child_thought_node.name if action not in self.children: child_state = self.state.apply_action(action) child_node = MCTSNode( state=child_state, thought_node=child_thought_node, parent=self, action=action ) child_node.prior = priors.get(action, 1.0 / len(self.thought_node.children)) self.children[action] = child_node def is_leaf(self): return len(self.children) == 0 def ucb_score(self, total_visits, exploration_constant=math.sqrt(2)): if self.visit_count == 0: return float('inf') # Ensure unvisited nodes are selected first avg_value = self.value_sum / self.visit_count exploration_term = exploration_constant * self.prior * math.sqrt(total_visits) / (1 + self.visit_count) entropy_term = -0.1 * self.entropy # Slightly prefer lower entropy variance_term = 0.05 * self.variance # Slightly prefer higher variance return avg_value + exploration_term + entropy_term + variance_term class MCTS: def __init__(self, prediction_network, dynamics_network, action_encoder, num_iterations=10, exploration_constant=math.sqrt(2), beam_size=5, n_tokens_predict=3): self.prediction_network = prediction_network self.dynamics_network = dynamics_network self.action_encoder = action_encoder self.num_iterations = num_iterations self.exploration_constant = exploration_constant self.beam_size = beam_size self.n_tokens_predict = n_tokens_predict self.cache = {} def search_with_beam(self, root_state): root_node = MCTSNode(state=root_state, thought_node=root_state.thought_node) # Evaluate the root node and backpropagate value_estimate = self.evaluate(root_node) # Evaluate and expand root_node self.backpropagate(root_node, value_estimate) # Backpropagate the value beam = [(root_node, 0.0, 0.0, 0.0, [])] # (node, score, cum_entropy, cum_variance, action_sequence) for iteration in range(self.num_iterations): all_candidates = [] for node, score, cum_entropy, cum_variance, action_sequence in beam: if node.is_leaf(): value_estimate = self.evaluate(node) self.backpropagate(node, value_estimate) # Backpropagate after evaluation if len(node.children) == 0: continue # No children to expand total_visits = sum(child.visit_count for child in node.children.values()) # Select top actions based on UCB score sorted_children = sorted( node.children.items(), key=lambda item: item[1].ucb_score(total_visits, self.exploration_constant), reverse=True )[:self.beam_size] for selected_action, selected_node in sorted_children: current_node = selected_node current_sequence = action_sequence + [selected_action] current_score = score current_entropy = cum_entropy + selected_node.entropy current_variance = cum_variance + selected_node.variance # Predict n_tokens_predict actions for _ in range(self.n_tokens_predict): if current_node.is_leaf(): value_estimate = self.evaluate(current_node) self.backpropagate(current_node, value_estimate) # Backpropagate after evaluation if len(current_node.children) == 0: break # No more actions total_visits = sum(child.visit_count for child in current_node.children.values()) next_action, next_node = max( current_node.children.items(), key=lambda item: item[1].ucb_score(total_visits, self.exploration_constant) ) current_sequence.append(next_action) # Prevent division by zero by ensuring visit_count > 0 if next_node.visit_count > 0: current_score += next_node.value_sum / next_node.visit_count else: # Assign a default value or handle the zero division case current_score += 0.0 # Alternatively, use a small epsilon or skip current_entropy += next_node.entropy current_variance += next_node.variance current_node = next_node all_candidates.append((current_node, current_score, current_entropy, current_variance, current_sequence)) if not all_candidates: break # No more candidates to expand # Select top beam_size candidates beam = sorted(all_candidates, key=lambda x: x[1] - 0.1 * x[2] + 0.05 * x[3], reverse=True)[:self.beam_size] print(f"Iteration {iteration + 1}: Beam size after sorting: {len(beam)}") # Debug if beam: best_sequence = beam[0][4] return best_sequence else: return [] def search(self, root_state): root_node = MCTSNode(state=root_state, thought_node=root_state.thought_node) for _ in range(self.num_iterations): node = self.select(root_node) value = self.evaluate(node) self.backpropagate(node, value) return self.best_action_sequence(root_node) def select(self, node): while not node.is_leaf(): total_visits = sum(child.visit_count for child in node.children.values()) _, node = max( node.children.items(), key=lambda item: item[1].ucb_score(total_visits, self.exploration_constant) ) return node def evaluate(self, node): # Extract the last time step state_representation = node.state.representation[:, -1, :] # Shape: (batch_size=1, state_dim) print(f"Evaluating node with state_representation shape: {state_representation.shape}") # Debug policy_logits, value_estimate = self.prediction_network(state_representation) print(f"Policy logits shape: {policy_logits.shape}, Value estimate shape: {value_estimate.shape}") # Debug value_estimate = value_estimate.item() # Now safe as batch_size=1 policy_probs = F.softmax(policy_logits, dim=-1).squeeze(0) # Shape: (action_vocab_size,) print(f"Policy probabilities shape: {policy_probs.shape}") # Debug priors = {} for child in node.thought_node.children: action_name = child.name action_idx = action_to_index.get(action_name, None) if action_idx is not None and action_idx < policy_probs.size(0): priors[action_name] = policy_probs[action_idx].item() else: priors[action_name] = 1.0 / len(node.thought_node.children) node.expand(priors) # Calculate entropy and variance entropy = -torch.sum(policy_probs * torch.log(policy_probs + 1e-9)) variance = torch.var(policy_probs) node.entropy = entropy.item() node.variance = variance.item() print(f"Node entropy: {node.entropy}, variance: {node.variance}") # Debug return value_estimate # Return the value estimate for backpropagation def backpropagate(self, node, value): while node is not None: node.visit_count += 1 node.value_sum += value node = node.parent def best_action_sequence(self, root_node): sequences = [] self._generate_sequences(root_node, [], sequences) # Score sequences based on visit counts, entropy, and variance scored_sequences = [] for seq in sequences: score = sum(node.visit_count for node in seq) entropy = sum(node.entropy for node in seq) variance = sum(node.variance for node in seq) adjusted_score = score - 0.1 * entropy + 0.05 * variance scored_sequences.append((seq, adjusted_score)) # Sort sequences by adjusted score and select top beam_size best_sequences = sorted(scored_sequences, key=lambda x: x[1], reverse=True)[:self.beam_size] # Return the actions of the best sequence best_sequence = best_sequences[0][0] return [node.action for node in best_sequence[1:self.n_tokens_predict+1]] # Exclude root node def _generate_sequences(self, node, current_sequence, sequences): current_sequence.append(node) if len(current_sequence) > self.n_tokens_predict or not node.children: sequences.append(current_sequence) else: for child in node.children.values(): self._generate_sequences(child, current_sequence.copy(), sequences) class State: def __init__(self, representation, dynamics_network, action_encoder, thought_node): self.representation = representation self.dynamics_network = dynamics_network self.action_encoder = action_encoder self.thought_node = thought_node def apply_action(self, action): next_thought_node = None for child in self.thought_node.children: if child.name == action: next_thought_node = child break if next_thought_node is None: raise ValueError(f"Action '{action}' is not valid from the current thought node.") # Adjust action_index and action_embedding shapes action_index = torch.tensor([action_to_index[action]], device=self.representation.device) action_embedding = self.action_encoder(action_index) # Shape: (batch_size=1, action_dim) # Extract the last time step of the state state = self.representation[:, -1, :] # Shape: (batch_size, state_dim) # Ensure action_embedding matches the state dimension next_state_representation = self.dynamics_network(state, action_embedding) # Shape: (batch_size, state_dim) # Append the new state to the representation history new_representation = torch.cat([self.representation, next_state_representation.unsqueeze(1)], dim=1) # Shape: (batch_size, seq_len+1, state_dim) return State( representation=new_representation, dynamics_network=self.dynamics_network, action_encoder=self.action_encoder, thought_node=next_thought_node ) class PPOAgent: def __init__(self, policy_network, optimizer, clip_epsilon=0.2, entropy_coef=0.01, value_coef=0.5): self.policy_network = policy_network self.optimizer = optimizer self.clip_epsilon = clip_epsilon self.entropy_coef = entropy_coef self.value_coef = value_coef def compute_loss(self, states, old_log_probs, actions, returns, advantages): # Get policy logits and value estimates policy_logits, value_estimates = self.policy_network(states) batch_size, seq_len, num_actions = policy_logits.size() # Flatten tensors using reshape policy_logits = policy_logits.reshape(-1, num_actions) # Shape: (batch_size * seq_len, num_actions) value_estimates = value_estimates.view(-1) actions = actions.reshape(-1) # Shape: (batch_size * seq_len) old_log_probs = old_log_probs.reshape(-1) # Shape: (batch_size * seq_len) returns = returns.view(-1) advantages = advantages.reshape(-1) # Shape: (batch_size * seq_len) # Ensure value_estimates and returns are the same size if value_estimates.size() != returns.size(): print(f"Shape mismatch: value_estimates shape: {value_estimates.size()}, returns shape: {returns.size()}") value_estimates = value_estimates[:returns.size(0)] # Compute new log probabilities new_log_probs_all = F.log_softmax(policy_logits, dim=-1) # Shape: (batch_size * seq_len, num_actions) new_log_probs = new_log_probs_all.gather(1, actions.unsqueeze(-1)).squeeze(-1) # Shape: (batch_size * seq_len) # Compute ratios ratios = torch.exp(new_log_probs - old_log_probs) # PPO surrogate loss surr1 = ratios * advantages surr2 = torch.clamp(ratios, 1 - self.clip_epsilon, 1 + self.clip_epsilon) * advantages policy_loss = -torch.min(surr1, surr2).mean() # Value loss value_loss = F.mse_loss(value_estimates, returns) # Entropy loss entropy = -(new_log_probs * torch.exp(new_log_probs)).mean() # Total loss total_loss = policy_loss + self.value_coef * value_loss - self.entropy_coef * entropy return total_loss # Tree of Thought Components class ThoughtNode: def __init__(self, name): self.name = name self.children = [] self.parent = None def add_child(self, child_node): child_node.parent = self self.children.append(child_node) # Function to build the Tree of Thought from your detailed structure def build_tree_of_thought(): # Create the root node root = ThoughtNode('Problem-Solving Process') # Level 1 nodes problem_identification = ThoughtNode('Problem Identification') problem_analysis = ThoughtNode('Problem Analysis') solution_generation = ThoughtNode('Solution Generation') implementation = ThoughtNode('Implementation') evaluation_adjustment = ThoughtNode('Evaluation and Adjustment') root.add_child(problem_identification) root.add_child(problem_analysis) root.add_child(solution_generation) root.add_child(implementation) root.add_child(evaluation_adjustment) # Problem Identification children B1 = ThoughtNode('Define the Problem') B2 = ThoughtNode('Identify Stakeholders') B3 = ThoughtNode('Determine Constraints') B4 = ThoughtNode('Recognize Problem Type') B5 = ThoughtNode('Historical Context') problem_identification.add_child(B1) problem_identification.add_child(B2) problem_identification.add_child(B3) problem_identification.add_child(B4) problem_identification.add_child(B5) # Define the Problem children B1a = ThoughtNode('Problem Statement Formulation') B1b = ThoughtNode('Scope Definition') B1c = ThoughtNode('Objective Setting') B1.add_child(B1a) B1.add_child(B1b) B1.add_child(B1c) # Identify Stakeholders children B2a = ThoughtNode('Stakeholder Mapping') B2b = ThoughtNode('Interest and Influence Analysis') B2c = ThoughtNode('Engagement Strategy') B2.add_child(B2a) B2.add_child(B2b) B2.add_child(B2c) # Determine Constraints children B3a = ThoughtNode('Resource Limitations') B3b = ThoughtNode('Time Constraints') B3c = ThoughtNode('Legal and Regulatory Constraints') B3.add_child(B3a) B3.add_child(B3b) B3.add_child(B3c) # Recognize Problem Type children B4a = ThoughtNode('Simple vs Complex') B4b = ThoughtNode('Known vs Unknown') B4c = ThoughtNode('Tame vs Wicked Problems') B4.add_child(B4a) B4.add_child(B4b) B4.add_child(B4c) # Historical Context children B5a = ThoughtNode('Previous Attempts') B5b = ThoughtNode('Lessons Learned') B5c = ThoughtNode('Environmental Factors') B5.add_child(B5a) B5.add_child(B5b) B5.add_child(B5c) # Problem Analysis children C1 = ThoughtNode('Root Cause Analysis') C2 = ThoughtNode('System Mapping') C3 = ThoughtNode('Data Collection') C4 = ThoughtNode('Impact Assessment') C5 = ThoughtNode('Theoretical Framework') problem_analysis.add_child(C1) problem_analysis.add_child(C2) problem_analysis.add_child(C3) problem_analysis.add_child(C4) problem_analysis.add_child(C5) # Root Cause Analysis children C1a = ThoughtNode('5 Whys Technique') C1b = ThoughtNode('Fishbone Diagram') C1c = ThoughtNode('Pareto Analysis') C1.add_child(C1a) C1.add_child(C1b) C1.add_child(C1c) # System Mapping children C2a = ThoughtNode('Causal Loop Diagrams') C2b = ThoughtNode('Stock and Flow Models') C2c = ThoughtNode('Network Analysis') C2.add_child(C2a) C2.add_child(C2b) C2.add_child(C2c) # Data Collection children C3a = ThoughtNode('Quantitative Data') C3b = ThoughtNode('Qualitative Data') C3c = ThoughtNode('Data Validation') C3.add_child(C3a) C3.add_child(C3b) C3.add_child(C3c) # Quantitative Data children C3a1 = ThoughtNode('Surveys and Questionnaires') C3a2 = ThoughtNode('Experimental Data') C3a3 = ThoughtNode('Big Data Analytics') C3a.add_child(C3a1) C3a.add_child(C3a2) C3a.add_child(C3a3) # Qualitative Data children C3b1 = ThoughtNode('Interviews') C3b2 = ThoughtNode('Focus Groups') C3b3 = ThoughtNode('Observational Studies') C3b.add_child(C3b1) C3b.add_child(C3b2) C3b.add_child(C3b3) # Data Validation children C3c1 = ThoughtNode('Statistical Validation') C3c2 = ThoughtNode('Cross-Validation') C3c3 = ThoughtNode('Expert Review') C3c.add_child(C3c1) C3c.add_child(C3c2) C3c.add_child(C3c3) # Impact Assessment children C4a = ThoughtNode('Environmental Impact') C4b = ThoughtNode('Social Impact') C4c = ThoughtNode('Economic Impact') C4.add_child(C4a) C4.add_child(C4b) C4.add_child(C4c) # Theoretical Framework children C5a = ThoughtNode('Literature Review') C5b = ThoughtNode('Conceptual Modeling') C5c = ThoughtNode('Hypothesis Formation') C5.add_child(C5a) C5.add_child(C5b) C5.add_child(C5c) # Solution Generation children D1 = ThoughtNode('Creative Problem Solving') D2 = ThoughtNode('Analytical Approach') D3 = ThoughtNode('Mathematical Computation') D4 = ThoughtNode('Decision Making') solution_generation.add_child(D1) solution_generation.add_child(D2) solution_generation.add_child(D3) solution_generation.add_child(D4) # Action Planning, Resource Allocation, Change Management children (implementation phase) E1 = ThoughtNode('Action Planning') E2 = ThoughtNode('Resource Allocation') E3 = ThoughtNode('Change Management') implementation.add_child(E1) implementation.add_child(E2) implementation.add_child(E3) # Verification, Performance Metrics, Feedback Loops, Continuous Improvement children (evaluation phase) F1 = ThoughtNode('Verification') F2 = ThoughtNode('Performance Metrics') F3 = ThoughtNode('Feedback Loops') F4 = ThoughtNode('Continuous Improvement') evaluation_adjustment.add_child(F1) evaluation_adjustment.add_child(F2) evaluation_adjustment.add_child(F3) evaluation_adjustment.add_child(F4) # Cross-Cutting Considerations children G = ThoughtNode('Cross-Cutting Considerations') root.add_child(G) # Cross-Cutting Considerations children G1 = ThoughtNode('Ethical Framework') G2 = ThoughtNode('Stakeholder Management') G3 = ThoughtNode('Interdisciplinary Connections') G4 = ThoughtNode('Technological Integration') G5 = ThoughtNode('Emotional Intelligence') G6 = ThoughtNode('Collaborative Problem Solving') G7 = ThoughtNode('Computational Considerations') # Assuming H was intended as G7 G8 = ThoughtNode('Order of Operations') # Assuming I was intended as G8 G9 = ThoughtNode('Critical Thinking') # Assuming J was intended as G9 G10 = ThoughtNode('Future Perspective') # Assuming K was intended as G10 G11 = ThoughtNode('Learning and Adaptation') # Assuming L was intended as G11 G.add_child(G1) G.add_child(G2) G.add_child(G3) G.add_child(G4) G.add_child(G5) G.add_child(G6) G.add_child(G7) G.add_child(G8) G.add_child(G9) G.add_child(G10) G.add_child(G11) # Ethical Framework children G1a = ThoughtNode('Value-based Decision Making') G1b = ThoughtNode('Long-term Consequences') G1.add_child(G1a) G1.add_child(G1b) # Value-based Decision Making children G1a1 = ThoughtNode('Ethical Theories Application') G1a2 = ThoughtNode('Moral Dilemma Resolution') G1a.add_child(G1a1) G1a.add_child(G1a2) # Long-term Consequences children G1b1 = ThoughtNode('Sustainability Assessment') G1b2 = ThoughtNode('Intergenerational Impact') G1b.add_child(G1b1) G1b.add_child(G1b2) # Stakeholder Management children G2a = ThoughtNode('Direct Stakeholders') G2b = ThoughtNode('Indirect Stakeholders') G2c = ThoughtNode('Conflicting Interests') G2.add_child(G2a) G2.add_child(G2b) G2.add_child(G2c) # Conflicting Interests children G2c1 = ThoughtNode('Negotiation Strategies') G2c2 = ThoughtNode('Conflict Resolution Techniques') G2c.add_child(G2c1) G2c.add_child(G2c2) # Interdisciplinary Connections children G3a = ThoughtNode('Related Fields') G3b = ThoughtNode('Cross-disciplinary Impact') G3.add_child(G3a) G3.add_child(G3b) # Related Fields children G3a1 = ThoughtNode('Cross-domain Knowledge Transfer') G3a2 = ThoughtNode('Interdisciplinary Collaboration') G3a.add_child(G3a1) G3a.add_child(G3a2) # Cross-disciplinary Impact children G3b1 = ThoughtNode('Synergy Identification') G3b2 = ThoughtNode('Holistic Impact Assessment') G3b.add_child(G3b1) G3b.add_child(G3b2) # Technological Integration children G4a = ThoughtNode('AI-assisted Problem Solving') G4b = ThoughtNode('Data-driven Insights') G4c = ThoughtNode('Digital Collaboration Tools') G4.add_child(G4a) G4.add_child(G4b) G4.add_child(G4c) # AI-assisted Problem Solving children G4a1 = ThoughtNode('Machine Learning Models') G4a2 = ThoughtNode('Natural Language Processing') G4a.add_child(G4a1) G4a.add_child(G4a2) # Data-driven Insights children G4b1 = ThoughtNode('Big Data Analytics') G4b2 = ThoughtNode('Predictive Modeling') G4b.add_child(G4b1) G4b.add_child(G4b2) # Digital Collaboration Tools children G4c1 = ThoughtNode('Project Management Platforms') G4c2 = ThoughtNode('Virtual Reality Collaboration') G4c.add_child(G4c1) G4c.add_child(G4c2) # Emotional Intelligence children G5a = ThoughtNode('Self-Awareness') G5b = ThoughtNode('Empathy') G5c = ThoughtNode('Stress Management') G5.add_child(G5a) G5.add_child(G5b) G5.add_child(G5c) # Self-Awareness children G5a1 = ThoughtNode('Emotional Recognition') G5a2 = ThoughtNode('Personal Bias Identification') G5a.add_child(G5a1) G5a.add_child(G5a2) # Empathy children G5b1 = ThoughtNode('Perspective Taking') G5b2 = ThoughtNode('Active Listening') G5b.add_child(G5b1) G5b.add_child(G5b2) # Stress Management children G5c1 = ThoughtNode('Mindfulness Techniques') G5c2 = ThoughtNode('Resilience Building') G5c.add_child(G5c1) G5c.add_child(G5c2) # Collaborative Problem Solving children G6a = ThoughtNode('Team Dynamics') G6b = ThoughtNode('Communication Strategies') G6c = ThoughtNode('Conflict Resolution') G6.add_child(G6a) G6.add_child(G6b) G6.add_child(G6c) # Team Dynamics children G6a1 = ThoughtNode('Team Formation Strategies') G6a2 = ThoughtNode('Role Assignment') G6a.add_child(G6a1) G6a.add_child(G6a2) # Communication Strategies children G6b1 = ThoughtNode('Clear Messaging') G6b2 = ThoughtNode('Feedback Mechanisms') G6b.add_child(G6b1) G6b.add_child(G6b2) # Conflict Resolution children G6c1 = ThoughtNode('Mediation Techniques') G6c2 = ThoughtNode('Consensus Building') G6c.add_child(G6c1) G6c.add_child(G6c2) # Computational Considerations children G7a = ThoughtNode('CPU Operations') G7b = ThoughtNode('GPU Parallelization') G7c = ThoughtNode('Floating-Point Precision') G7.add_child(G7a) G7.add_child(G7b) G7.add_child(G7c) # CPU Operations children G7a1 = ThoughtNode('Instruction Set Architecture') G7a2 = ThoughtNode('Pipelining and Parallelism') G7a.add_child(G7a1) G7a.add_child(G7a2) # GPU Parallelization children G7b1 = ThoughtNode('CUDA Programming') G7b2 = ThoughtNode('OpenCL Framework') G7b.add_child(G7b1) G7b.add_child(G7b2) # Floating-Point Precision children G7c1 = ThoughtNode('IEEE 754 Standard') G7c2 = ThoughtNode('Error Propagation Analysis') G7c.add_child(G7c1) G7c.add_child(G7c2) # Order of Operations children G8a = ThoughtNode('Parentheses') G8b = ThoughtNode('Exponents') G8c = ThoughtNode('Multiplication and Division') G8d = ThoughtNode('Addition and Subtraction') G8.add_child(G8a) G8.add_child(G8b) G8.add_child(G8c) G8.add_child(G8d) # Critical Thinking children G9a = ThoughtNode('Assumptions Questioning') G9b = ThoughtNode('Bias Recognition') G9.add_child(G9a) G9.add_child(G9b) # Assumptions Questioning children G9a1 = ThoughtNode('Socratic Questioning') G9a2 = ThoughtNode('Devil\'s Advocate Approach') G9a.add_child(G9a1) G9a.add_child(G9a2) # Bias Recognition children G9b1 = ThoughtNode('Cognitive Bias Identification') G9b2 = ThoughtNode('Debiasing Techniques') G9b.add_child(G9b1) G9b.add_child(G9b2) # Future Perspective children G10a = ThoughtNode('Short-term Projections') G10b = ThoughtNode('Long-term Scenarios') G10c = ThoughtNode('Potential Impacts') G10.add_child(G10a) G10.add_child(G10b) G10.add_child(G10c) # Short-term Projections children G10a1 = ThoughtNode('Trend Analysis') G10a2 = ThoughtNode('Scenario Planning') G10a.add_child(G10a1) G10a.add_child(G10a2) # Long-term Scenarios children G10b1 = ThoughtNode('Futures Wheel') G10b2 = ThoughtNode('Backcasting') G10b.add_child(G10b1) G10b.add_child(G10b2) # Potential Impacts children G10c1 = ThoughtNode('Risk Assessment') G10c2 = ThoughtNode('Opportunity Identification') G10c.add_child(G10c1) G10c.add_child(G10c2) # Learning and Adaptation children G11a = ThoughtNode('Reflective Practice') G11b = ThoughtNode('Knowledge Transfer') G11c = ThoughtNode('Adaptive Problem Solving') G11.add_child(G11a) G11.add_child(G11b) G11.add_child(G11c) # Reflective Practice children G11a1 = ThoughtNode('After Action Review') G11a2 = ThoughtNode('Learning Journals') G11a.add_child(G11a1) G11a.add_child(G11a2) # Knowledge Transfer children G11b1 = ThoughtNode('Best Practice Documentation') G11b2 = ThoughtNode('Mentoring Programs') G11b.add_child(G11b1) G11b.add_child(G11b2) # Adaptive Problem Solving children G11c1 = ThoughtNode('Iterative Approaches') G11c2 = ThoughtNode('Flexibility in Methodology') G11c.add_child(G11c1) G11c.add_child(G11c2) return root def traverse_tree(node, action_list): if node.name not in action_list: action_list.append(node.name) for child in node.children: traverse_tree(child, action_list) def infer(query, world_model_components, root_thought_node, tokenizer, max_length=20, inference_mode='world_model', beam_size=5, n_tokens_predict=3, mcts_iterations=10, exploration_constant=1.414): """ Perform inference given a query, utilizing the Tree of Thought and MCTS with multi-token beam search. Args: query (str): The input query or prompt. world_model_components (tuple): Tuple containing the model components. root_thought_node (ThoughtNode): The root node of the Tree of Thought. tokenizer (transformers.PreTrainedTokenizer): The tokenizer used. max_length (int): Maximum length for the generated sequence. inference_mode (str): Inference mode ('world_model', 'without_world_model', 'world_model_tree_of_thought') beam_size (int): Size of the beam for beam search n_tokens_predict (int): Number of tokens to predict at each step Returns: List[str] or str: The sequence of actions (thoughts) selected or generated text. """ representation_network, dynamics_network, prediction_network, action_encoder, ppo_agent, model_transformer = world_model_components # Tokenize and encode the query input_ids = tokenizer.encode(query, return_tensors='pt').to(device) attention_mask = (input_ids != tokenizer.pad_token_id).long() if inference_mode == 'without_world_model': # Directly use the transformer model to generate text with beam search with torch.no_grad(): generated_sequences = model_transformer.generate_with_beam_search( src=input_ids, tokenizer=tokenizer, beam_size=beam_size, max_length=max_length, n_tokens_predict=n_tokens_predict, temperature=args.temperature ) best_sequence, best_score = generated_sequences[0] generated_text = tokenizer.decode(best_sequence[0], skip_special_tokens=True) return generated_text else: # Use the world model components with torch.no_grad(): transformer_output = model_transformer(input_ids, input_ids) # Get the initial state representation initial_representation = representation_network(transformer_output) # Shape: (batch_size=1, seq_len, state_dim) initial_representation = initial_representation[:, -1, :].unsqueeze(1) # Shape: (batch_size=1, 1, state_dim) initial_state = State( representation=initial_representation, dynamics_network=dynamics_network, action_encoder=action_encoder, thought_node=root_thought_node ) if inference_mode == 'world_model_tree_of_thought': # Use MCTS with Tree of Thought and multi-token beam search mcts = MCTS(prediction_network, dynamics_network, action_encoder, num_iterations=mcts_iterations, exploration_constant=exploration_constant) current_state = initial_state thought_sequence = [] for _ in range(max_length // n_tokens_predict): best_actions = mcts.search_with_beam(current_state) thought_sequence.extend(best_actions) # Apply the best actions to get the next state for action in best_actions: current_state = current_state.apply_action(action) # Check if we've reached a leaf node (no further actions) if len(current_state.thought_node.children) == 0: break return thought_sequence else: # Use the world model without Tree of Thought, but with multi-token beam search beam = [(initial_state, 0.0, torch.zeros(1, device=device), torch.zeros(1, device=device))] # (state, score, cum_entropy, cum_variance) for _ in range(max_length // n_tokens_predict): all_candidates = [] for state, score, cum_entropy, cum_variance in beam: policy_logits, _ = prediction_network(state.representation) probs = F.softmax(policy_logits / args.temperature, dim=-1) entropy = -torch.sum(probs * torch.log(probs + 1e-9), dim=-1) variance = torch.var(probs, dim=-1) topk_probs, topk_indices = torch.topk(probs, k=beam_size, dim=-1) for i in range(beam_size ** n_tokens_predict): indices = [i // (beam_size ** j) % beam_size for j in range(n_tokens_predict)] new_actions = [index_to_action[topk_indices[0, j, indices[j]].item()] for j in range(n_tokens_predict)] new_score = score + torch.sum(torch.log(topk_probs[0, range(n_tokens_predict), indices])) new_entropy = cum_entropy + torch.sum(entropy[0, indices]) new_variance = cum_variance + torch.sum(variance[0, indices]) new_state = state for action in new_actions: new_state = new_state.apply_action(action) all_candidates.append((new_state, new_score, new_entropy, new_variance, new_actions)) # Select top beam_size candidates beam = sorted(all_candidates, key=lambda x: x[1] - 0.1 * x[2] + 0.05 * x[3], reverse=True)[:beam_size] # Accumulate actions if not thought_sequence: thought_sequence = [b[4] for b in beam] else: for i, b in enumerate(beam): thought_sequence[i].extend(b[4]) # Return the top sequence return thought_sequence[0] def train_epoch_world_model(world_model_components, train_loader, optimizer, scheduler, scaler, args, model_transformer, state_dim, embed_dim, input_dim): representation_network, dynamics_network, prediction_network, action_encoder, ppo_agent, _ = world_model_components representation_network.train() dynamics_network.train() prediction_network.train() action_encoder.train() ppo_agent.policy_network.train() total_loss = 0.0 optimizer.zero_grad() print(f"Starting World Model training epoch with {len(train_loader)} batches...") for i, batch in enumerate(train_loader): print(f"Processing batch {i+1}/{len(train_loader)}...") # Move batches to the device src_batch = batch['input_ids'].to(device) tgt_batch = batch['labels'].to(device) with torch.amp.autocast(device_type='cuda'): print("Forward pass through Transformer (frozen)...") with torch.no_grad(): transformer_output = model_transformer(src_batch, tgt_batch[:, :-1]) # World Model - Representation state_representation = representation_network(transformer_output) # For simplicity, let's assume true actions are provided (e.g., next tokens) true_actions = tgt_batch[:, :-1] action_sequences = true_actions # Get action embeddings action_embeddings = action_encoder(action_sequences) # Apply dynamics network predicted_next_state_batch = dynamics_network(state_representation, action_embeddings) # Prediction Network - Policy logits and value policy_logits, value_estimates = prediction_network(predicted_next_state_batch) # Define true_policy and true_value as placeholders on the GPU true_policy = F.one_hot(true_actions, num_classes=input_dim).float() true_value = torch.zeros_like(value_estimates).to(device) # Compute individual losses ppo_loss = ppo_agent.compute_loss( state_representation, torch.zeros_like(true_actions, dtype=torch.float32).to(device), true_actions, torch.zeros_like(value_estimates, dtype=torch.float32).to(device), torch.zeros_like(value_estimates, dtype=torch.float32).to(device) ) info_nce = InfoNCE_Loss()( state_representation.view(-1, state_dim), F.dropout(state_representation.view(-1, state_dim), p=0.1, training=True) ) covariance = CovarianceRegularization()(predicted_next_state_batch.view(-1, predicted_next_state_batch.size(-1))) dynamics_loss = DynamicsPerformanceLoss()(state_representation, predicted_next_state_batch) perturbed_next_state = predicted_next_state_batch + torch.randn_like(predicted_next_state_batch) * 0.01 thought_loss = ThoughtConsistencyLoss()(predicted_next_state_batch, perturbed_next_state) pv_loss = PolicyValueJointLoss()(policy_logits, true_policy, value_estimates.squeeze(-1), true_value.squeeze(-1)) action_diversity = ActionDiversityReward()(action_embeddings.view(-1, embed_dim)) mcts_best_values = torch.zeros(true_actions.size(0)).to(device) etv = ExpectedThoughtValueLoss()(mcts_best_values) visit_counts = torch.ones(true_actions.size(0), policy_logits.size(-1)).to(device) exploration = ExplorationRegularization()(visit_counts) old_policy = F.softmax(policy_logits.detach(), dim=-1) new_policy = F.softmax(policy_logits, dim=-1) kl_loss = KL_DivergenceLoss()(old_policy, new_policy) # Total Loss loss = ( ppo_loss + info_nce + covariance + dynamics_loss + thought_loss + pv_loss + action_diversity + etv + exploration + kl_loss ) loss = loss / args.accumulation_steps print("Backward pass...") scaler.scale(loss).backward() if (i + 1) % args.accumulation_steps == 0 or (i + 1) == len(train_loader): print("Gradient clipping...") scaler.unscale_(optimizer) torch.nn.utils.clip_grad_norm_( [param for group in optimizer.param_groups for param in group['params']], args.max_grad_norm ) print("Optimizer step...") scaler.step(optimizer) scaler.update() print("Zeroing gradients...") optimizer.zero_grad() print("Updating learning rate...") scheduler.step() total_loss += loss.item() * args.accumulation_steps # Print individual losses and total loss for this batch print(f"Batch {i+1} completed. Losses:") print(f" PPO Loss: {ppo_loss.item():.4f}") print(f" InfoNCE Loss: {info_nce.item():.4f}") print(f" Covariance Loss: {covariance.item():.4f}") print(f" Dynamics Loss: {dynamics_loss.item():.4f}") print(f" Thought Consistency Loss: {thought_loss.item():.4f}") print(f" Policy-Value Loss: {pv_loss.item():.4f}") print(f" Action Diversity Loss: {action_diversity.item():.4f}") print(f" Expected Thought Value Loss: {etv.item():.4f}") print(f" Exploration Loss: {exploration.item():.4f}") print(f" KL Divergence Loss: {kl_loss.item():.4f}") print(f" Total Loss: {loss.item():.4f}") avg_loss = total_loss / len(train_loader) print(f"World Model training epoch completed. Average loss: {avg_loss:.4f}") return avg_loss def train_epoch_language_model(model, train_loader, optimizer, scheduler, scaler, args): model.train() total_loss = 0.0 optimizer.zero_grad() print(f"Starting Language Model training epoch with {len(train_loader)} batches...") for i, batch in enumerate(train_loader): input_ids = batch['input_ids'].to(device) labels = batch['labels'].to(device) with autocast(): outputs = model(input_ids, input_ids) logits = outputs.view(-1, outputs.size(-1)) labels = labels.view(-1) loss = F.cross_entropy(logits, labels, ignore_index=model.embedding.padding_idx) loss = loss / args.accumulation_steps scaler.scale(loss).backward() if (i + 1) % args.accumulation_steps == 0 or (i + 1) == len(train_loader): scaler.unscale_(optimizer) torch.nn.utils.clip_grad_norm_( [param for group in optimizer.param_groups for param in group['params']], args.max_grad_norm ) scaler.step(optimizer) scaler.update() optimizer.zero_grad() scheduler.step() total_loss += loss.item() * args.accumulation_steps print(f"Batch {i + 1} completed. Current loss: {loss.item():.4f}") avg_loss = total_loss / len(train_loader) print(f"Language Model training epoch completed. Average loss: {avg_loss:.4f}") return avg_loss def main(): args = parse_args() print("Arguments parsed successfully.") # Create save directory os.makedirs(args.save_dir, exist_ok=True) print(f"Save directory created: {args.save_dir}") # Load tokenizer print("Loading tokenizer...") tokenizer = AutoTokenizer.from_pretrained(args.model_name) if tokenizer.pad_token is None: tokenizer.pad_token = tokenizer.eos_token print("Tokenizer loaded successfully.") # Define padding_idx and input dimension based on tokenizer padding_idx = tokenizer.pad_token_id input_dim = len(tokenizer) # Initialize the Transformer model on GPU print("Initializing Transformer model...") model_transformer = Transformer( input_dim=input_dim, d_model=128, num_heads=4, num_layers=4, d_ff=256, num_experts=2, output_dim=input_dim, dropout=0.1, top_k=2 ).to(device) model_transformer.train() print("Transformer model initialized on device.") # Define model parameters (adjusted for speed) d_model = 128 state_dim = 128 action_dim = d_model hidden_dim = 256 vocab_dim = input_dim embed_dim = d_model # Define World Model components representation_network = RepresentationNetwork(vocab_dim, d_model, state_dim).to(device) dynamics_network = DynamicsNetwork(state_dim, action_dim, hidden_dim).to(device) prediction_network = PredictionNetwork(state_dim, input_dim, 1).to(device) action_encoder = ActionEncoder(input_dim, action_dim).to(device) # Initialize PPO Agent ppo_agent = PPOAgent( policy_network=prediction_network, optimizer=optim.AdamW(prediction_network.parameters(), lr=args.learning_rate), clip_epsilon=0.2, entropy_coef=0.01, value_coef=0.5 ) # Bundle World Model components world_model_components = (representation_network, dynamics_network, prediction_network, action_encoder, ppo_agent, model_transformer) print(f"Current mode: {args.mode}") if args.mode == 'train': print("Loading and preprocessing data...") train_loader, eval_loader = load_data(args, tokenizer) print("Data loaded and preprocessed successfully.") # Optimizer and Scheduler optimizer = optim.AdamW( list(representation_network.parameters()) + list(dynamics_network.parameters()) + list(prediction_network.parameters()) + list(action_encoder.parameters()), lr=args.learning_rate, weight_decay=args.weight_decay ) if args.train_mode == 'world_model' else optim.AdamW(model_transformer.parameters(), lr=args.learning_rate) scheduler = CosineAnnealingLR(optimizer, T_max=args.num_epochs) scaler = GradScaler() print(f"Starting {args.train_mode} training...") for epoch in range(args.num_epochs): if args.train_mode == 'world_model': avg_loss = train_epoch_world_model( world_model_components, train_loader, optimizer, scheduler, scaler, args, model_transformer, state_dim, embed_dim, input_dim ) else: avg_loss = train_epoch_language_model( model_transformer, train_loader, optimizer, scheduler, scaler, args ) print(f"{args.train_mode.capitalize()} training epoch {epoch + 1} completed. Average loss: {avg_loss:.4f}") if args.train_mode == 'world_model': save_all_models(model_transformer, representation_network, dynamics_network, prediction_network, action_encoder, args.save_dir, epoch + 1) print(f"Models saved for epoch {epoch + 1}") else: torch.save(model_transformer.state_dict(), os.path.join(args.save_dir, f'language_model_epoch_{epoch + 1}.pt')) print(f"Language model saved for epoch {epoch + 1}") print("Training completed.") elif args.mode == 'inference': print("Entering inference mode...") # Build Tree of Thought if needed print("Building Tree of Thought...") tree_root = build_tree_of_thought() print("Tree of Thought built successfully.") # Generate action list print("Generating action list...") action_list = [] traverse_tree(tree_root, action_list) print(f"Action list generated. Total actions: {len(action_list)}") # Create mappings global action_to_index, index_to_action action_to_index = {action: idx for idx, action in enumerate(action_list)} index_to_action = {idx: action for action, idx in action_to_index.items()} action_vocab_size = len(action_list) print(f"Action mappings created. Vocabulary size: {action_vocab_size}") # Initialize or load models based on the load_model argument if args.load_model: print(f"Loading saved model from {args.load_model}") # Load the saved models model_transformer.load_state_dict(torch.load(os.path.join(args.load_model, 'transformer_model.pt'))) representation_network.load_state_dict(torch.load(os.path.join(args.load_model, 'representation_network.pt'))) dynamics_network.load_state_dict(torch.load(os.path.join(args.load_model, 'dynamics_network.pt'))) # Load prediction network and adjust its size if necessary saved_state_dict = torch.load(os.path.join(args.load_model, 'prediction_network.pt')) saved_vocab_size = saved_state_dict['policy_head.weight'].size(0) if saved_vocab_size != action_vocab_size: print(f"Adjusting prediction network size from {saved_vocab_size} to {action_vocab_size}") prediction_network = PredictionNetwork(state_dim, saved_vocab_size, 1).to(device) prediction_network.load_state_dict(saved_state_dict) prediction_network.policy_head = nn.Linear(prediction_network.state_dim, action_vocab_size).to(device) else: prediction_network = PredictionNetwork(state_dim, action_vocab_size, 1).to(device) prediction_network.load_state_dict(saved_state_dict) action_encoder.load_state_dict(torch.load(os.path.join(args.load_model, 'action_encoder.pt'))) else: print("Using newly initialized models") # Prepare the components world_model_components = (representation_network, dynamics_network, prediction_network, action_encoder, ppo_agent, model_transformer) print("Starting inference loop...") while True: if args.query: query = args.query args.query = None # Reset query for next iteration else: query = input("Please enter your query (or type 'exit' to quit): ") if query.lower() == 'exit': break print(f"Processing query: {query}") result = infer(query, world_model_components, tree_root, tokenizer, max_length=args.max_length, inference_mode=args.inference_mode, beam_size=args.beam_size, n_tokens_predict=args.n_tokens_predict, mcts_iterations=args.mcts_iterations, exploration_constant=args.mcts_exploration_constant) if args.inference_mode == 'without_world_model': print("Generated Text:") print(result) else: print("Generated Thought Sequence:") for thought in result: print(thought) print("\n") # Add a newline for better readability between queries print("Inference completed.") else: print(f"Invalid mode: {args.mode}. Please choose 'train' or 'inference'.") if __name__ == '__main__': main()