Update embeddings.py
Browse files- embeddings.py +343 -140
embeddings.py
CHANGED
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@@ -3,92 +3,186 @@ import torch.nn as nn
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import torch.nn.functional as F
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import math
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from typing import Optional, Tuple, List
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class PositionalEncoding(nn.Module):
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self.d_model = d_model
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self.dropout = nn.Dropout(dropout)
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pe = torch.zeros(max_seq_len, d_model)
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position = torch.arange(0, max_seq_len, dtype=torch.float).unsqueeze(1)
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div_term = torch.exp(torch.arange(0, d_model, 2).float() *
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-(math.log(10000.0) / d_model))
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pe[:, 0::2] = torch.sin(position * div_term)
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if d_model % 2 == 1
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batch_size, seq_len, d_model = x.size()
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return self.dropout(x)
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class LearnedPositionalEmbedding(nn.Module):
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self.max_seq_len = max_seq_len
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self.d_model = d_model
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self.pos_embedding = nn.Embedding(max_seq_len, d_model)
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self.dropout = nn.Dropout(dropout)
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nn.init.normal_(self.pos_embedding.weight, std=0.02)
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batch_size, seq_len, d_model = x.size()
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if seq_len > self.max_seq_len:
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raise ValueError(f"Sequence length {seq_len} exceeds maximum {self.max_seq_len}")
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positions = torch.arange(seq_len, device=x.device).unsqueeze(0).expand(batch_size, -1)
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pos_emb = self.pos_embedding(positions)
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x = x + pos_emb
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return self.dropout(x)
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class RotaryPositionalEmbedding(nn.Module):
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self.d_model = d_model
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self.max_seq_len = max_seq_len
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self.base = base
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inv_freq = 1.0 / (base ** (torch.arange(0, d_model, 2).float() / d_model))
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self.register_buffer('inv_freq', inv_freq)
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self._seq_len_cached = 0
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self._cos_cached = None
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self._sin_cached = None
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if seq_len > self._seq_len_cached:
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self._seq_len_cached = seq_len
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t = torch.arange(seq_len, device=device, dtype=torch.float32)
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freqs = torch.outer(t, self.inv_freq)
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self._cos_cached = freqs.cos().to(dtype)
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self._sin_cached = freqs.sin().to(dtype)
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def forward(self, q: torch.Tensor, k: torch.Tensor, start_pos: int = 0) -> Tuple[torch.Tensor, torch.Tensor]:
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batch_size, seq_len, num_heads, head_dim = q.shape
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self._update_cos_sin_cache(start_pos + seq_len, q.device, q.dtype)
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cos = self._cos_cached[start_pos:start_pos + seq_len, :head_dim // 2]
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sin = self._sin_cached[start_pos:start_pos + seq_len, :head_dim // 2]
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sin = sin.view(1, seq_len, 1, -1)
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q = q.transpose(1, 2).reshape(batch_size * num_heads, seq_len, head_dim)
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k = k.transpose(1, 2).reshape(batch_size * num_heads, seq_len, head_dim)
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q_rot = self._rotate_half(q, cos, sin)
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k_rot = self._rotate_half(k, cos, sin)
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q_rot = q_rot.reshape(batch_size, num_heads, seq_len, head_dim).transpose(1, 2)
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k_rot = k_rot.reshape(batch_size, num_heads, seq_len, head_dim).transpose(1, 2)
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return q_rot, k_rot
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x1 = x[..., :x.shape[-1] // 2]
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x2 = x[..., x.shape[-1] // 2:]
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return torch.cat([x1 * cos - x2 * sin, x1 * sin + x2 * cos], dim=-1)
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class TechEmbeddingLayer(nn.Module):
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self.d_model = d_model
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self.vocab_size = vocab_size
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self.padding_idx = padding_idx
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self.
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if pos_encoding == "sinusoidal":
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self.pos_encoding = PositionalEncoding(d_model, max_seq_len, dropout)
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elif pos_encoding == "learned":
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elif pos_encoding == "rope":
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self.pos_encoding = RotaryPositionalEmbedding(d_model, max_seq_len)
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else:
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raise ValueError(f"Unknown positional encoding type: {pos_encoding}")
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self.layer_norm = nn.LayerNorm(d_model) if layer_norm else nn.Identity()
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self.dropout = nn.Dropout(dropout)
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self._init_weights()
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nn.init.normal_(self.token_embedding.weight, mean=0.0, std=0.02)
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if self.padding_idx is not None:
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nn.init.constant_(self.token_embedding.weight[self.padding_idx], 0.0)
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def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
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if (input_ids >= self.vocab_size).any():
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raise ValueError(f"Input IDs contain values >= vocab_size ({self.vocab_size})")
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embeddings = self.token_embedding(input_ids)
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if self.pos_encoding_type != "rope":
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embeddings = self.pos_encoding(embeddings)
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embeddings = self.layer_norm(embeddings)
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def get_positional_encoding(self):
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return self.pos_encoding if self.pos_encoding_type == "rope" else None
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class AdaptiveEmbedding(nn.Module):
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self.vocab_size = vocab_size
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self.d_model = d_model
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self.cutoffs = [0] + cutoffs + [vocab_size]
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self.div_val = div_val
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self.embeddings = nn.ModuleList()
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self.projections = nn.ModuleList()
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for i in range(len(self.cutoffs) - 1):
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l_idx = self.cutoffs[i]
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d_emb = int(d_model / (div_val ** i))
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emb = nn.Embedding(r_idx - l_idx, d_emb)
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nn.init.normal_(emb.weight, mean=0.0, std=0.02)
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self.embeddings.append(emb)
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if d_emb != d_model:
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self.projections.append(proj)
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else:
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self.projections.append(nn.Identity())
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def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
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if (input_ids >= self.vocab_size).any():
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raise ValueError(f"Input IDs contain values >= vocab_size ({self.vocab_size})")
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batch_size, seq_len = input_ids.shape
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embeddings = torch.zeros(batch_size, seq_len, self.d_model,
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for i in range(len(self.cutoffs) - 1):
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l_idx = self.cutoffs[i]
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r_idx = self.cutoffs[i + 1]
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mask = (input_ids >= l_idx) & (input_ids < r_idx)
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if mask.any():
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indices = input_ids[mask] - l_idx
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indices = indices.clamp(max=r_idx - l_idx - 1)
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emb = self.embeddings[i](indices)
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embeddings[mask] = emb
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return embeddings
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return input_ids == padding_idx
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def create_causal_mask(seq_len: int, device: torch.device) -> torch.Tensor:
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return torch.triu(torch.ones(seq_len, seq_len, device=device), diagonal=1).bool()
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batch_size, seq_len = input_ids.shape
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device = input_ids.device
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padding_mask = create_padding_mask(input_ids, padding_idx)
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padding_mask = padding_mask.unsqueeze(1).expand(batch_size, seq_len, seq_len)
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if causal:
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causal_mask = create_causal_mask(seq_len, device)
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combined_mask = padding_mask
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return combined_mask
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class EmbeddingAnalyzer:
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def __init__(self, embedding_layer: nn.Module):
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if hasattr(self.embedding_layer, 'token_embedding'):
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embeddings = self.embedding_layer.token_embedding.weight
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elif hasattr(self.embedding_layer, 'embeddings'):
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embeddings.append(proj(w))
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embeddings = torch.cat(embeddings, dim=0)
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else:
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embeddings = self.embedding_layer.weight
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if tokens is not None and len(tokens) > 0:
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embeddings = embeddings[tokens]
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def find_similar_tokens(self, token_id: int, top_k: int = 10) -> List[Tuple[int, float]]:
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similarity_matrix = self.get_similarity_matrix()
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similarities = similarity_matrix[token_id]
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top_similarities, top_indices = torch.topk(similarities, top_k + 1)
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mask = top_indices != token_id
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if hasattr(self.embedding_layer, 'token_embedding'):
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weights = self.embedding_layer.token_embedding.weight
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elif hasattr(self.embedding_layer, 'embeddings'):
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weights = torch.cat([emb.weight for emb in self.embedding_layer.embeddings], dim=0)
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else:
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weights = self.embedding_layer.weight
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'mean': weights.mean().item(),
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'std': weights.std().item(),
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'min': weights.min().item(),
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'max': weights.max().item(),
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'norm_mean': weights.norm(dim=1).mean().item(),
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'norm_std': weights.norm(dim=1).std().item()
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}
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def test_embeddings():
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vocab_size = 1000
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d_model = 512
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max_seq_len = 128
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batch_size = 4
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seq_len = 64
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embedding_types = [
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("Learned Position", "learned"),
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("Sinusoidal Position", "sinusoidal"),
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("RoPE", "rope")
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for name, pos_type in embedding_types:
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print(f"\nTesting {name} Embedding:")
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embedding_layer = TechEmbeddingLayer(
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vocab_size=vocab_size,
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d_model=d_model,
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max_seq_len=max_seq_len,
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pos_encoding=pos_type
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)
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embeddings = embedding_layer(input_ids)
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print(f"Input shape: {input_ids.shape}")
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print(f"Output shape: {embeddings.shape}")
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print(f"Expected shape: ({batch_size}, {seq_len}, {d_model})")
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analyzer = EmbeddingAnalyzer(embedding_layer)
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stats = analyzer.analyze_embedding_distribution()
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print(f"Embedding statistics:")
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for key, value in stats.items():
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print(f" {key}: {value:.4f}")
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)
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embeddings = adaptive_emb(input_ids)
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print(f"
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input_ids_padded = input_ids.clone()
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input_ids_padded[:, -10:] = 0
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padding_mask = create_padding_mask(input_ids_padded, padding_idx=0)
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causal_mask = create_causal_mask(seq_len, input_ids.device)
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attention_mask = create_attention_mask(input_ids_padded, padding_idx=0, causal=True)
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print(f"Padding mask shape: {padding_mask.shape}")
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print(f"Causal mask shape: {causal_mask.shape}")
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print(f"Attention mask shape: {attention_mask.shape}")
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print(f"Padding positions: {padding_mask.sum().item()}")
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print(f"Causal mask positions: {causal_mask.sum().item()}")
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print(f"Combined mask positions: {attention_mask.sum().item()}")
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print("\nAll embedding tests completed successfully!")
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if __name__ == "__main__":
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test_embeddings()
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import torch.nn.functional as F
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import math
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from typing import Optional, Tuple, List
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# Constants for default configuration
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DEFAULT_MAX_SEQ_LEN = 512
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DEFAULT_DROPOUT = 0.1
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DEFAULT_BASE = 10000.0
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DEFAULT_CUTOFFS = [2000, 10000]
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DEFAULT_DIV_VAL = 4.0
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DEFAULT_PADDING_IDX = 0
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class PositionalEncoding(nn.Module):
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+
"""Sinusoidal positional encoding for transformer models."""
|
| 17 |
+
|
| 18 |
+
def __init__(self, d_model: int, max_seq_len: int = DEFAULT_MAX_SEQ_LEN, dropout: float = DEFAULT_DROPOUT):
|
| 19 |
+
"""
|
| 20 |
+
Initialize sinusoidal positional encoding.
|
| 21 |
+
|
| 22 |
+
Args:
|
| 23 |
+
d_model (int): Dimension of the model embeddings.
|
| 24 |
+
max_seq_len (int): Maximum sequence length for positional encodings.
|
| 25 |
+
dropout (float): Dropout rate for regularization.
|
| 26 |
+
"""
|
| 27 |
+
super().__init__()
|
| 28 |
self.d_model = d_model
|
| 29 |
+
self.dropout = nn.Dropout(dropout)
|
| 30 |
+
|
| 31 |
pe = torch.zeros(max_seq_len, d_model)
|
| 32 |
position = torch.arange(0, max_seq_len, dtype=torch.float).unsqueeze(1)
|
| 33 |
+
div_term = torch.exp(torch.arange(0, d_model, 2).float() * (-math.log(DEFAULT_BASE) / d_model))
|
|
|
|
| 34 |
pe[:, 0::2] = torch.sin(position * div_term)
|
| 35 |
+
pe[:, 1::2] = torch.cos(position * div_term[:, :-1] if d_model % 2 == 1 else div_term)
|
| 36 |
+
self.register_buffer('pe', pe.unsqueeze(0))
|
| 37 |
+
|
| 38 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 39 |
+
"""
|
| 40 |
+
Apply positional encoding to input embeddings.
|
| 41 |
+
|
| 42 |
+
Args:
|
| 43 |
+
x (torch.Tensor): Input tensor of shape (batch_size, seq_len, d_model).
|
| 44 |
+
|
| 45 |
+
Returns:
|
| 46 |
+
torch.Tensor: Tensor with positional encodings applied.
|
| 47 |
+
"""
|
| 48 |
batch_size, seq_len, d_model = x.size()
|
| 49 |
+
if d_model != self.d_model:
|
| 50 |
+
raise ValueError(f"Input dimension {d_model} does not match d_model {self.d_model}")
|
| 51 |
+
x = x + self.pe[:, :seq_len]
|
| 52 |
return self.dropout(x)
|
| 53 |
+
|
| 54 |
class LearnedPositionalEmbedding(nn.Module):
|
| 55 |
+
"""Learned positional embeddings for transformer models."""
|
| 56 |
+
|
| 57 |
+
def __init__(self, max_seq_len: int, d_model: int, dropout: float = DEFAULT_DROPOUT):
|
| 58 |
+
"""
|
| 59 |
+
Initialize learned positional embeddings.
|
| 60 |
+
|
| 61 |
+
Args:
|
| 62 |
+
max_seq_len (int): Maximum sequence length.
|
| 63 |
+
d_model (int): Dimension of the model embeddings.
|
| 64 |
+
dropout (float): Dropout rate for regularization.
|
| 65 |
+
"""
|
| 66 |
+
super().__init__()
|
| 67 |
self.max_seq_len = max_seq_len
|
| 68 |
+
self.d_model = d_model
|
| 69 |
self.pos_embedding = nn.Embedding(max_seq_len, d_model)
|
| 70 |
self.dropout = nn.Dropout(dropout)
|
| 71 |
+
nn.init.normal_(self.pos_embedding.weight, std=0.02)
|
| 72 |
+
|
| 73 |
+
def forward(self, x: torch.Tensor) -> torch.Tensor:
|
| 74 |
+
"""
|
| 75 |
+
Apply learned positional embeddings to input.
|
| 76 |
+
|
| 77 |
+
Args:
|
| 78 |
+
x (torch.Tensor): Input tensor of shape (batch_size, seq_len, d_model).
|
| 79 |
+
|
| 80 |
+
Returns:
|
| 81 |
+
torch.Tensor: Tensor with positional embeddings applied.
|
| 82 |
+
"""
|
| 83 |
batch_size, seq_len, d_model = x.size()
|
| 84 |
if seq_len > self.max_seq_len:
|
| 85 |
+
raise ValueError(f"Sequence length {seq_len} exceeds maximum {self.max_seq_len}")
|
| 86 |
+
if d_model != self.d_model:
|
| 87 |
+
raise ValueError(f"Input dimension {d_model} does not match d_model {self.d_model}")
|
| 88 |
positions = torch.arange(seq_len, device=x.device).unsqueeze(0).expand(batch_size, -1)
|
| 89 |
pos_emb = self.pos_embedding(positions)
|
| 90 |
x = x + pos_emb
|
| 91 |
return self.dropout(x)
|
| 92 |
+
|
| 93 |
class RotaryPositionalEmbedding(nn.Module):
|
| 94 |
+
"""Rotary Positional Embedding (RoPE) for transformer models."""
|
| 95 |
+
|
| 96 |
+
def __init__(self, d_model: int, max_seq_len: int = 2048, base: float = DEFAULT_BASE):
|
| 97 |
+
"""
|
| 98 |
+
Initialize rotary positional embeddings.
|
| 99 |
+
|
| 100 |
+
Args:
|
| 101 |
+
d_model (int): Dimension of the model embeddings.
|
| 102 |
+
max_seq_len (int): Maximum sequence length.
|
| 103 |
+
base (float): Base for frequency calculation.
|
| 104 |
+
"""
|
| 105 |
+
super().__init__()
|
| 106 |
self.d_model = d_model
|
| 107 |
self.max_seq_len = max_seq_len
|
| 108 |
+
self.base = base
|
| 109 |
inv_freq = 1.0 / (base ** (torch.arange(0, d_model, 2).float() / d_model))
|
| 110 |
+
self.register_buffer('inv_freq', inv_freq)
|
| 111 |
self._seq_len_cached = 0
|
| 112 |
self._cos_cached = None
|
| 113 |
+
self._sin_cached = None
|
| 114 |
+
|
| 115 |
+
def _update_cos_sin_cache(self, seq_len: int, device: torch.device, dtype: torch.dtype) -> None:
|
| 116 |
+
"""Update cached cosine and sine values for RoPE."""
|
| 117 |
if seq_len > self._seq_len_cached:
|
| 118 |
self._seq_len_cached = seq_len
|
| 119 |
t = torch.arange(seq_len, device=device, dtype=torch.float32)
|
| 120 |
freqs = torch.outer(t, self.inv_freq)
|
| 121 |
self._cos_cached = freqs.cos().to(dtype)
|
| 122 |
+
self._sin_cached = freqs.sin().to(dtype)
|
| 123 |
+
|
| 124 |
+
def _rotate_half(self, x: torch.Tensor, cos: torch.Tensor, sin: torch.Tensor) -> torch.Tensor:
|
| 125 |
+
"""Apply rotary transformation to half of the tensor."""
|
| 126 |
+
x1, x2 = x[..., :x.shape[-1] // 2], x[..., x.shape[-1] // 2:]
|
| 127 |
+
return torch.cat([x1 * cos - x2 * sin, x1 * sin + x2 * cos], dim=-1)
|
| 128 |
+
|
| 129 |
def forward(self, q: torch.Tensor, k: torch.Tensor, start_pos: int = 0) -> Tuple[torch.Tensor, torch.Tensor]:
|
| 130 |
+
"""
|
| 131 |
+
Apply rotary positional embeddings to query and key tensors.
|
| 132 |
+
|
| 133 |
+
Args:
|
| 134 |
+
q (torch.Tensor): Query tensor of shape (batch_size, seq_len, num_heads, head_dim).
|
| 135 |
+
k (torch.Tensor): Key tensor of shape (batch_size, seq_len, num_heads, head_dim).
|
| 136 |
+
start_pos (int): Starting position for positional encoding.
|
| 137 |
+
|
| 138 |
+
Returns:
|
| 139 |
+
Tuple[torch.Tensor, torch.Tensor]: Rotated query and key tensors.
|
| 140 |
+
"""
|
| 141 |
batch_size, seq_len, num_heads, head_dim = q.shape
|
| 142 |
+
self._update_cos_sin_cache(start_pos + seq_len, q.device, q.dtype)
|
| 143 |
+
cos = self._cos_cached[start_pos:start_pos + seq_len, :head_dim // 2].view(1, seq_len, 1, -1)
|
| 144 |
+
sin = self._sin_cached[start_pos:start_pos + seq_len, :head_dim // 2].view(1, seq_len, 1, -1)
|
| 145 |
+
|
|
|
|
| 146 |
q = q.transpose(1, 2).reshape(batch_size * num_heads, seq_len, head_dim)
|
| 147 |
+
k = k.transpose(1, 2).reshape(batch_size * num_heads, seq_len, head_dim)
|
| 148 |
q_rot = self._rotate_half(q, cos, sin)
|
| 149 |
+
k_rot = self._rotate_half(k, cos, sin)
|
| 150 |
q_rot = q_rot.reshape(batch_size, num_heads, seq_len, head_dim).transpose(1, 2)
|
| 151 |
+
k_rot = k_rot.reshape(batch_size, num_heads, seq_len, head_dim).transpose(1, 2)
|
| 152 |
+
return q_rot, k_rot
|
| 153 |
+
|
|
|
|
|
|
|
|
|
|
| 154 |
class TechEmbeddingLayer(nn.Module):
|
| 155 |
+
"""Comprehensive embedding layer with token and positional embeddings."""
|
| 156 |
+
|
| 157 |
+
def __init__(
|
| 158 |
+
self,
|
| 159 |
+
vocab_size: int,
|
| 160 |
+
d_model: int,
|
| 161 |
+
max_seq_len: int = DEFAULT_MAX_SEQ_LEN,
|
| 162 |
+
dropout: float = DEFAULT_DROPOUT,
|
| 163 |
+
padding_idx: int = DEFAULT_PADDING_IDX,
|
| 164 |
+
pos_encoding: str = "learned",
|
| 165 |
+
layer_norm: bool = True,
|
| 166 |
+
):
|
| 167 |
+
"""
|
| 168 |
+
Initialize the embedding layer.
|
| 169 |
+
|
| 170 |
+
Args:
|
| 171 |
+
vocab_size (int): Size of the vocabulary.
|
| 172 |
+
d_model (int): Dimension of the model embeddings.
|
| 173 |
+
max_seq_len (int): Maximum sequence length.
|
| 174 |
+
dropout (float): Dropout rate.
|
| 175 |
+
padding_idx (int): Index for padding token.
|
| 176 |
+
pos_encoding (str): Type of positional encoding ('sinusoidal', 'learned', 'rope').
|
| 177 |
+
layer_norm (bool): Whether to apply layer normalization.
|
| 178 |
+
"""
|
| 179 |
+
super().__init__()
|
| 180 |
self.d_model = d_model
|
| 181 |
self.vocab_size = vocab_size
|
| 182 |
+
self.padding_idx = padding_idx
|
| 183 |
+
self.pos_encoding_type = pos_encoding.lower()
|
| 184 |
+
|
| 185 |
+
self.token_embedding = nn.Embedding(vocab_size, d_model, padding_idx=padding_idx)
|
| 186 |
if pos_encoding == "sinusoidal":
|
| 187 |
self.pos_encoding = PositionalEncoding(d_model, max_seq_len, dropout)
|
| 188 |
elif pos_encoding == "learned":
|
|
|
|
| 190 |
elif pos_encoding == "rope":
|
| 191 |
self.pos_encoding = RotaryPositionalEmbedding(d_model, max_seq_len)
|
| 192 |
else:
|
| 193 |
+
raise ValueError(f"Unknown positional encoding type: {pos_encoding}")
|
| 194 |
+
|
| 195 |
self.layer_norm = nn.LayerNorm(d_model) if layer_norm else nn.Identity()
|
| 196 |
self.dropout = nn.Dropout(dropout)
|
| 197 |
+
self._init_weights()
|
| 198 |
+
|
| 199 |
+
def _init_weights(self) -> None:
|
| 200 |
+
"""Initialize weights for token embeddings."""
|
| 201 |
nn.init.normal_(self.token_embedding.weight, mean=0.0, std=0.02)
|
| 202 |
if self.padding_idx is not None:
|
| 203 |
+
nn.init.constant_(self.token_embedding.weight[self.padding_idx], 0.0)
|
| 204 |
+
|
| 205 |
def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
|
| 206 |
+
"""
|
| 207 |
+
Forward pass for embedding layer.
|
| 208 |
+
|
| 209 |
+
Args:
|
| 210 |
+
input_ids (torch.Tensor): Input tensor of shape (batch_size, seq_len).
|
| 211 |
+
|
| 212 |
+
Returns:
|
| 213 |
+
torch.Tensor: Embedded tensor of shape (batch_size, seq_len, d_model).
|
| 214 |
+
"""
|
| 215 |
if (input_ids >= self.vocab_size).any():
|
| 216 |
+
raise ValueError(f"Input IDs contain values >= vocab_size ({self.vocab_size})")
|
| 217 |
embeddings = self.token_embedding(input_ids)
|
| 218 |
if self.pos_encoding_type != "rope":
|
| 219 |
+
embeddings = self.pos_encoding(embeddings)
|
| 220 |
embeddings = self.layer_norm(embeddings)
|
| 221 |
+
return self.dropout(embeddings)
|
| 222 |
+
|
| 223 |
+
def get_positional_encoding(self) -> Optional[nn.Module]:
|
| 224 |
+
"""Return the positional encoding module if RoPE, else None."""
|
| 225 |
return self.pos_encoding if self.pos_encoding_type == "rope" else None
|
| 226 |
+
|
| 227 |
class AdaptiveEmbedding(nn.Module):
|
| 228 |
+
"""Adaptive embedding layer with variable embedding dimensions."""
|
| 229 |
+
|
| 230 |
+
def __init__(
|
| 231 |
+
self,
|
| 232 |
+
vocab_size: int,
|
| 233 |
+
d_model: int,
|
| 234 |
+
cutoffs: List[int] = DEFAULT_CUTOFFS,
|
| 235 |
+
div_val: float = DEFAULT_DIV_VAL,
|
| 236 |
+
):
|
| 237 |
+
"""
|
| 238 |
+
Initialize adaptive embedding layer.
|
| 239 |
+
|
| 240 |
+
Args:
|
| 241 |
+
vocab_size (int): Size of the vocabulary.
|
| 242 |
+
d_model (int): Dimension of the model embeddings.
|
| 243 |
+
cutoffs (List[int]): Cutoff points for vocabulary splits.
|
| 244 |
+
div_val (float): Division factor for embedding dimensions.
|
| 245 |
+
"""
|
| 246 |
+
super().__init__()
|
| 247 |
self.vocab_size = vocab_size
|
| 248 |
self.d_model = d_model
|
| 249 |
self.cutoffs = [0] + cutoffs + [vocab_size]
|
| 250 |
+
self.div_val = div_val
|
| 251 |
+
|
| 252 |
self.embeddings = nn.ModuleList()
|
| 253 |
+
self.projections = nn.ModuleList()
|
| 254 |
+
|
| 255 |
for i in range(len(self.cutoffs) - 1):
|
| 256 |
+
l_idx, r_idx = self.cutoffs[i], self.cutoffs[i + 1]
|
| 257 |
+
d_emb = int(d_model / (div_val ** i))
|
|
|
|
| 258 |
emb = nn.Embedding(r_idx - l_idx, d_emb)
|
| 259 |
nn.init.normal_(emb.weight, mean=0.0, std=0.02)
|
| 260 |
+
self.embeddings.append(emb)
|
| 261 |
+
self.projections.append(
|
| 262 |
+
nn.Linear(d_emb, d_model, bias=False) if d_emb != d_model else nn.Identity()
|
| 263 |
+
)
|
| 264 |
if d_emb != d_model:
|
| 265 |
+
nn.init.normal_(self.projections[-1].weight, mean=0.0, std=0.02)
|
| 266 |
+
|
|
|
|
|
|
|
|
|
|
| 267 |
def forward(self, input_ids: torch.Tensor) -> torch.Tensor:
|
| 268 |
+
"""
|
| 269 |
+
Forward pass for adaptive embedding.
|
| 270 |
+
|
| 271 |
+
Args:
|
| 272 |
+
input_ids (torch.Tensor): Input tensor of shape (batch_size, seq_len).
|
| 273 |
+
|
| 274 |
+
Returns:
|
| 275 |
+
torch.Tensor: Embedded tensor of shape (batch_size, seq_len, d_model).
|
| 276 |
+
"""
|
| 277 |
if (input_ids >= self.vocab_size).any():
|
| 278 |
+
raise ValueError(f"Input IDs contain values >= vocab_size ({self.vocab_size})")
|
| 279 |
batch_size, seq_len = input_ids.shape
|
| 280 |
+
embeddings = torch.zeros(batch_size, seq_len, self.d_model, device=input_ids.device, dtype=torch.float32)
|
| 281 |
+
|
| 282 |
for i in range(len(self.cutoffs) - 1):
|
| 283 |
+
l_idx, r_idx = self.cutoffs[i], self.cutoffs[i + 1]
|
|
|
|
| 284 |
mask = (input_ids >= l_idx) & (input_ids < r_idx)
|
| 285 |
if mask.any():
|
| 286 |
+
indices = (input_ids[mask] - l_idx).clamp(max=r_idx - l_idx - 1)
|
|
|
|
| 287 |
emb = self.embeddings[i](indices)
|
| 288 |
+
embeddings[mask] = self.projections[i](emb)
|
|
|
|
| 289 |
return embeddings
|
| 290 |
+
|
| 291 |
+
def create_padding_mask(input_ids: torch.Tensor, padding_idx: int = DEFAULT_PADDING_IDX) -> torch.Tensor:
|
| 292 |
+
"""
|
| 293 |
+
Create a padding mask for input IDs.
|
| 294 |
+
|
| 295 |
+
Args:
|
| 296 |
+
input_ids (torch.Tensor): Input tensor of shape (batch_size, seq_len).
|
| 297 |
+
padding_idx (int): Index for padding token.
|
| 298 |
+
|
| 299 |
+
Returns:
|
| 300 |
+
torch.Tensor: Padding mask of shape (batch_size, seq_len).
|
| 301 |
+
"""
|
| 302 |
return input_ids == padding_idx
|
| 303 |
+
|
| 304 |
def create_causal_mask(seq_len: int, device: torch.device) -> torch.Tensor:
|
| 305 |
+
"""
|
| 306 |
+
Create a causal mask for attention.
|
| 307 |
+
|
| 308 |
+
Args:
|
| 309 |
+
seq_len (int): Sequence length.
|
| 310 |
+
device (torch.device): Device for tensor allocation.
|
| 311 |
+
|
| 312 |
+
Returns:
|
| 313 |
+
torch.Tensor: Causal mask of shape (seq_len, seq_len).
|
| 314 |
+
"""
|
| 315 |
return torch.triu(torch.ones(seq_len, seq_len, device=device), diagonal=1).bool()
|
| 316 |
+
|
| 317 |
+
def create_attention_mask(input_ids: torch.Tensor, padding_idx: int = DEFAULT_PADDING_IDX, causal: bool = True) -> torch.Tensor:
|
| 318 |
+
"""
|
| 319 |
+
Create an attention mask combining padding and causal masks.
|
| 320 |
+
|
| 321 |
+
Args:
|
| 322 |
+
input_ids (torch.Tensor): Input tensor of shape (batch_size, seq_len).
|
| 323 |
+
padding_idx (int): Index for padding token.
|
| 324 |
+
causal (bool): Whether to include causal masking.
|
| 325 |
+
|
| 326 |
+
Returns:
|
| 327 |
+
torch.Tensor: Attention mask of shape (batch_size, seq_len, seq_len).
|
| 328 |
+
"""
|
| 329 |
batch_size, seq_len = input_ids.shape
|
| 330 |
device = input_ids.device
|
| 331 |
+
padding_mask = create_padding_mask(input_ids, padding_idx).unsqueeze(1).expand(batch_size, seq_len, seq_len)
|
|
|
|
|
|
|
| 332 |
if causal:
|
| 333 |
+
causal_mask = create_causal_mask(seq_len, device).unsqueeze(0).expand(batch_size, seq_len, seq_len)
|
| 334 |
+
return padding_mask | causal_mask
|
| 335 |
+
return padding_mask
|
| 336 |
+
|
|
|
|
|
|
|
|
|
|
| 337 |
class EmbeddingAnalyzer:
|
| 338 |
+
"""Analyzer for inspecting embedding layer properties."""
|
| 339 |
+
|
| 340 |
def __init__(self, embedding_layer: nn.Module):
|
| 341 |
+
"""
|
| 342 |
+
Initialize the embedding analyzer.
|
| 343 |
+
|
| 344 |
+
Args:
|
| 345 |
+
embedding_layer (nn.Module): The embedding layer to analyze.
|
| 346 |
+
"""
|
| 347 |
+
self.embedding_layer = embedding_layer
|
| 348 |
+
|
| 349 |
+
def get_similarity_matrix(self, tokens: Optional[List[int]] = None) -> torch.Tensor:
|
| 350 |
+
"""
|
| 351 |
+
Compute the cosine similarity matrix for embeddings.
|
| 352 |
+
|
| 353 |
+
Args:
|
| 354 |
+
tokens (Optional[List[int]]): List of token IDs to compute similarities for.
|
| 355 |
+
|
| 356 |
+
Returns:
|
| 357 |
+
torch.Tensor: Cosine similarity matrix.
|
| 358 |
+
"""
|
| 359 |
if hasattr(self.embedding_layer, 'token_embedding'):
|
| 360 |
embeddings = self.embedding_layer.token_embedding.weight
|
| 361 |
elif hasattr(self.embedding_layer, 'embeddings'):
|
| 362 |
+
embeddings = torch.cat(
|
| 363 |
+
[self.embedding_layer.projections[i](emb.weight) for i, emb in enumerate(self.embedding_layer.embeddings)],
|
| 364 |
+
dim=0
|
| 365 |
+
)
|
|
|
|
|
|
|
| 366 |
else:
|
| 367 |
+
embeddings = self.embedding_layer.weight
|
| 368 |
+
|
| 369 |
if tokens is not None and len(tokens) > 0:
|
| 370 |
+
embeddings = embeddings[tokens]
|
| 371 |
+
return torch.mm(F.normalize(embeddings, p=2, dim=1), F.normalize(embeddings, p=2, dim=1).t())
|
| 372 |
+
|
| 373 |
def find_similar_tokens(self, token_id: int, top_k: int = 10) -> List[Tuple[int, float]]:
|
| 374 |
+
"""
|
| 375 |
+
Find the top-k most similar tokens to a given token ID.
|
| 376 |
+
|
| 377 |
+
Args:
|
| 378 |
+
token_id (int): Token ID to find similar tokens for.
|
| 379 |
+
top_k (int): Number of similar tokens to return.
|
| 380 |
+
|
| 381 |
+
Returns:
|
| 382 |
+
List[Tuple[int, float]]: List of (token_id, similarity_score) pairs.
|
| 383 |
+
"""
|
| 384 |
similarity_matrix = self.get_similarity_matrix()
|
| 385 |
+
if token_id >= similarity_matrix.shape[0]:
|
| 386 |
+
raise ValueError(f"Token ID {token_id} is out of range")
|
| 387 |
similarities = similarity_matrix[token_id]
|
| 388 |
top_similarities, top_indices = torch.topk(similarities, top_k + 1)
|
| 389 |
mask = top_indices != token_id
|
| 390 |
+
return list(zip(top_indices[mask][:top_k].tolist(), top_similarities[mask][:top_k].tolist()))
|
| 391 |
+
|
| 392 |
+
def analyze_embedding_distribution(self) -> dict:
|
| 393 |
+
"""
|
| 394 |
+
Analyze the statistical properties of the embedding weights.
|
| 395 |
+
|
| 396 |
+
Returns:
|
| 397 |
+
dict: Dictionary containing mean, std, min, max, norm_mean, and norm_std of embeddings.
|
| 398 |
+
"""
|
| 399 |
if hasattr(self.embedding_layer, 'token_embedding'):
|
| 400 |
weights = self.embedding_layer.token_embedding.weight
|
| 401 |
elif hasattr(self.embedding_layer, 'embeddings'):
|
| 402 |
weights = torch.cat([emb.weight for emb in self.embedding_layer.embeddings], dim=0)
|
| 403 |
else:
|
| 404 |
+
weights = self.embedding_layer.weight
|
| 405 |
+
return {
|
| 406 |
'mean': weights.mean().item(),
|
| 407 |
'std': weights.std().item(),
|
| 408 |
'min': weights.min().item(),
|
| 409 |
'max': weights.max().item(),
|
| 410 |
'norm_mean': weights.norm(dim=1).mean().item(),
|
| 411 |
+
'norm_std': weights.norm(dim=1).std().item(),
|
| 412 |
}
|
| 413 |
+
|
| 414 |
+
def test_embeddings() -> None:
|
| 415 |
+
"""Test the embedding layers and related utilities."""
|
| 416 |
+
print("Starting embedding layer tests...")
|
| 417 |
vocab_size = 1000
|
| 418 |
d_model = 512
|
| 419 |
max_seq_len = 128
|
| 420 |
batch_size = 4
|
| 421 |
+
seq_len = 64
|
| 422 |
+
|
| 423 |
+
input_ids = torch.randint(1, vocab_size, (batch_size, seq_len))
|
| 424 |
embedding_types = [
|
| 425 |
("Learned Position", "learned"),
|
| 426 |
("Sinusoidal Position", "sinusoidal"),
|
| 427 |
+
("RoPE", "rope"),
|
| 428 |
+
]
|
| 429 |
+
|
| 430 |
for name, pos_type in embedding_types:
|
| 431 |
print(f"\nTesting {name} Embedding:")
|
| 432 |
embedding_layer = TechEmbeddingLayer(
|
| 433 |
vocab_size=vocab_size,
|
| 434 |
d_model=d_model,
|
| 435 |
max_seq_len=max_seq_len,
|
| 436 |
+
pos_encoding=pos_type,
|
| 437 |
+
)
|
| 438 |
embeddings = embedding_layer(input_ids)
|
| 439 |
+
assert embeddings.shape == (batch_size, seq_len, d_model), f"Unexpected shape for {name}: {embeddings.shape}"
|
| 440 |
print(f"Input shape: {input_ids.shape}")
|
| 441 |
print(f"Output shape: {embeddings.shape}")
|
| 442 |
+
print(f"Expected shape: ({batch_size}, {seq_len}, {d_model})")
|
| 443 |
+
|
| 444 |
analyzer = EmbeddingAnalyzer(embedding_layer)
|
| 445 |
stats = analyzer.analyze_embedding_distribution()
|
| 446 |
print(f"Embedding statistics:")
|
| 447 |
for key, value in stats.items():
|
| 448 |
+
print(f" {key}: {value:.4f}")
|
| 449 |
+
|
| 450 |
+
# Test similarity for a sample token
|
| 451 |
+
similar_tokens = analyzer.find_similar_tokens(token_id=0, top_k=5)
|
| 452 |
+
print(f"Top 5 similar tokens to token 0: {similar_tokens}")
|
| 453 |
+
|
| 454 |
+
print("\nTesting Adaptive Embeddings:")
|
| 455 |
+
adaptive_emb = AdaptiveEmbedding(vocab_size=vocab_size, d_model=d_model, cutoffs=[200, 500], div_val=2.0)
|
| 456 |
embeddings = adaptive_emb(input_ids)
|
| 457 |
+
assert embeddings.shape == (batch_size, seq_len, d_model), f"Unexpected adaptive embedding shape: {embeddings.shape}"
|
| 458 |
+
print(f"Adaptive embedding output shape: {embeddings.shape}")
|
| 459 |
+
|
| 460 |
+
print("\nTesting masking functions:")
|
| 461 |
input_ids_padded = input_ids.clone()
|
| 462 |
input_ids_padded[:, -10:] = 0
|
| 463 |
padding_mask = create_padding_mask(input_ids_padded, padding_idx=0)
|
| 464 |
causal_mask = create_causal_mask(seq_len, input_ids.device)
|
| 465 |
+
attention_mask = create_attention_mask(input_ids_padded, padding_idx=0, causal=True)
|
| 466 |
+
|
| 467 |
+
assert padding_mask.shape == (batch_size, seq_len), f"Unexpected padding mask shape: {padding_mask.shape}"
|
| 468 |
+
assert causal_mask.shape == (seq_len, seq_len), f"Unexpected causal mask shape: {causal_mask.shape}"
|
| 469 |
+
assert attention_mask.shape == (batch_size, seq_len, seq_len), f"Unexpected attention mask shape: {attention_mask.shape}"
|
| 470 |
print(f"Padding mask shape: {padding_mask.shape}")
|
| 471 |
print(f"Causal mask shape: {causal_mask.shape}")
|
| 472 |
print(f"Attention mask shape: {attention_mask.shape}")
|
| 473 |
print(f"Padding positions: {padding_mask.sum().item()}")
|
| 474 |
print(f"Causal mask positions: {causal_mask.sum().item()}")
|
| 475 |
+
print(f"Combined mask positions: {attention_mask.sum().item()}")
|
| 476 |
+
|
| 477 |
print("\nAll embedding tests completed successfully!")
|
| 478 |
+
|
| 479 |
if __name__ == "__main__":
|
| 480 |
test_embeddings()
|