软注意力机制超长超长版代码
时间: 2023-07-01 22:26:32 浏览: 101
好的,以下是一个更加详细的基于PyTorch实现的软注意力机制的代码示例:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
class SoftAttention(nn.Module):
def __init__(self, encoder_hidden_size, decoder_hidden_size, attention_hidden_size):
super(SoftAttention, self).__init__()
self.encoder_hidden_size = encoder_hidden_size
self.decoder_hidden_size = decoder_hidden_size
self.attention_hidden_size = attention_hidden_size
# 定义线性层,用于将encoder_outputs和decoder_hidden变换到attention_hidden_size的维度
self.encoder_linear = nn.Linear(encoder_hidden_size, attention_hidden_size, bias=False)
self.decoder_linear = nn.Linear(decoder_hidden_size, attention_hidden_size, bias=False)
self.attention_weights = nn.Linear(attention_hidden_size, 1, bias=False)
def forward(self, encoder_outputs, decoder_hidden):
"""
Args:
encoder_outputs: encoder端的输出,shape为(batch_size, seq_len, encoder_hidden_size)
decoder_hidden: decoder端的隐藏状态,shape为(batch_size, decoder_hidden_size)
Returns:
context: 加权后的上下文向量,shape为(batch_size, encoder_hidden_size)
weights: 注意力权重,shape为(batch_size, seq_len)
"""
batch_size, seq_len, _ = encoder_outputs.size()
# 将encoder_outputs和decoder_hidden变换到attention_hidden_size的维度
encoder_outputs = self.encoder_linear(encoder_outputs)
decoder_hidden = self.decoder_linear(decoder_hidden).unsqueeze(1).repeat(1, seq_len, 1)
# 计算注意力权重,先将encoder_outputs和decoder_hidden相加,再通过线性层变换到1维,最后使用softmax函数得到注意力权重
weights = self.attention_weights(torch.tanh(encoder_outputs + decoder_hidden))
weights = F.softmax(weights, dim=1)
# 对encoder_outputs进行加权求和,得到上下文向量
context = torch.bmm(weights.transpose(1, 2), encoder_outputs).squeeze(1)
return context, weights
```
在这个代码中,我们首先定义了一个名为SoftAttention的类,继承自nn.Module。在类的初始化函数中,我们传入encoder_hidden_size、decoder_hidden_size和attention_hidden_size三个参数,它们分别表示encoder端的隐藏状态的维度、decoder端的隐藏状态的维度和注意力权重的维度。接着,我们定义了三个线性层,用于将encoder_outputs和decoder_hidden变换到attention_hidden_size的维度,并定义了一个线性层,用于计算注意力权重。在forward方法中,我们首先将encoder_outputs和decoder_hidden变换到attention_hidden_size的维度,
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