| 201 | |
| 202 | # from https://pytorch.org/tutorials/beginner/transformer_tutorial.html |
| 203 | class PositionalEncoding(nn.Module): |
| 204 | |
| 205 | def __init__(self, d_model, dropout=0.1, max_len=5000): |
| 206 | super(PositionalEncoding, self).__init__() |
| 207 | self.dropout = nn.Dropout(p=dropout) |
| 208 | |
| 209 | pe = torch.zeros(max_len, d_model) |
| 210 | position = torch.arange(0, max_len, dtype=torch.float).unsqueeze(1) |
| 211 | div_term = torch.exp(torch.arange(0, d_model, 2).float() * (-math.log(10000.0) / d_model)) |
| 212 | pe[:, 0::2] = torch.sin(position * div_term) |
| 213 | pe[:, 1::2] = torch.cos(position * div_term) |
| 214 | pe = pe.unsqueeze(0).transpose(0, 1) |
| 215 | self.register_buffer('pe', pe) |
| 216 | |
| 217 | def forward(self, x): |
| 218 | # print('[DEBUG] input size:', x.size()) |
| 219 | # print('[DEBUG] positional embedding size:', self.pe.size()) |
| 220 | x = x + self.pe[:x.size(0), :] |
| 221 | # print('[DEBUG] output x with pe size:', x.size()) |
| 222 | return self.dropout(x) |
| 223 | |
| 224 | |
| 225 | """ Miscellaneous (not working well) """ |