位置编码 文本序列

 import torch

import math

 

def get_positional_encoding(max_len, d_model):

    pe = torch.zeros(max_len, d_model)

    position = torch.arange(0, max_len, dtype=torch.float).unsqueeze(1)

    div_term = torch.exp(torch.arange(0, d_model, 2).float() * (-math.log(10000.0) / d_model))

    pe[:, 0::2] = torch.sin(position * div_term)

    pe[:, 1::2] = torch.cos(position * div_term)

    return pe.unsqueeze(0) # (1, max_len, d_model)

 

# 示例

max_len = 50

d_model = 512

positional_encoding = get_positional_encoding(max_len, d_model)

print(positional_encoding.shape) # 输出: torch.Size([1, 50, 512])