写一个利用多头注意力机制处理多维时序数据的代码
时间: 2023-05-17 16:04:43 浏览: 342
当然,我可以为您提供一个基于Transformer的多头注意力机制处理多维时序数据的代码示例:
```
import torch
import torch.nn as nn
import torch.nn.functional as F
class MultiHeadAttention(nn.Module):
def __init__(self, d_model, num_heads):
super(MultiHeadAttention, self).__init__()
self.num_heads = num_heads
self.d_model = d_model
assert d_model % num_heads == 0
self.depth = d_model // num_heads
self.query_linear = nn.Linear(d_model, d_model)
self.key_linear = nn.Linear(d_model, d_model)
self.value_linear = nn.Linear(d_model, d_model)
self.output_linear = nn.Linear(d_model, d_model)
def split_heads(self, x, batch_size):
x = x.view(batch_size, -1, self.num_heads, self.depth)
return x.permute(0, 2, 1, 3)
def forward(self, query, key, value, mask=None):
batch_size = query.size(0)
query = self.query_linear(query)
key = self.key_linear(key)
value = self.value_linear(value)
query = self.split_heads(query, batch_size)
key = self.split_heads(key, batch_size)
value = self.split_heads(value, batch_size)
scaled_attention_logits = torch.matmul(query, key.permute(0, 1, 3, 2)) / torch.sqrt(torch.tensor(self.depth, dtype=torch.float32))
if mask is not None:
scaled_attention_logits += (mask * -1e9)
attention_weights = F.softmax(scaled_attention_logits, dim=-1)
output = torch.matmul(attention_weights, value)
output = output.permute(0, 2, 1, 3).contiguous()
output = output.view(batch_size, -1, self.d_model)
output = self.output_linear(output)
return output
```
这个代码实现了一个多头注意力机制,可以用于处理多维时序数据。其中,d_model表示输入数据的维度,num_heads表示注意力头的数量。在forward函数中,输入的query、key、value都是形状为(batch_size, seq_len, d_model)的张量,其中seq_len表示时序数据的长度。如果需要进行mask操作,可以传入一个形状为(batch_size, num_heads, seq_len, seq_len)的张量作为mask参数。
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