多头注意力机制代码语音
时间: 2023-10-16 19:16:18 浏览: 84
注意力机制的一些代码整理
抱歉,语音回答需要语音合成技术,目前我还没有这个能力。但我可以为你提供多头注意力机制的代码示例:
```python
import torch
import torch.nn as nn
class MultiHeadAttention(nn.Module):
def __init__(self, n_heads, d_model, dropout=0.1):
super().__init__()
assert d_model % n_heads == 0
self.n_heads = n_heads
self.d_model = d_model
self.head_dim = d_model // n_heads
self.q_linear = nn.Linear(d_model, d_model)
self.k_linear = nn.Linear(d_model, d_model)
self.v_linear = nn.Linear(d_model, d_model)
self.dropout = nn.Dropout(dropout)
self.out_linear = nn.Linear(d_model, d_model)
def forward(self, query, key, value, mask=None):
batch_size = query.shape[0]
# Project inputs to multi-head attention space
query = self.q_linear(query)
key = self.k_linear(key)
value = self.v_linear(value)
# Reshape inputs to [batch_size, n_heads, seq_len, head_dim]
query = query.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
key = key.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
value = value.view(batch_size, -1, self.n_heads, self.head_dim).transpose(1, 2)
# Compute attention scores and apply mask if given
scores = torch.matmul(query, key.transpose(-2, -1)) / torch.sqrt(torch.tensor(self.head_dim, dtype=torch.float32))
if mask is not None:
scores = scores.masked_fill(mask == 0, -1e9)
# Apply softmax to get attention probabilities
attn_probs = torch.softmax(scores, dim=-1)
attn_probs = self.dropout(attn_probs)
# Compute weighted sum of values
weighted_sum = torch.matmul(attn_probs, value)
# Reshape and project back to original space
weighted_sum = weighted_sum.transpose(1, 2).contiguous().view(batch_size, -1, self.d_model)
output = self.out_linear(weighted_sum)
return output, attn_probs
```
这是一个用 PyTorch 实现的多头注意力机制模块,可以用于自然语言处理等任务中。需要注意的是,在使用时需要传入 query、key 和 value 三个输入,并且可以选择传入掩码 mask,以便在计算注意力分数时过滤掉无效的信息。
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