| import torch | |
| import torch.nn.functional as F | |
| import torch.nn as nn | |
| from torch.nn import MultiheadAttention, GRU, Linear, LayerNorm, Dropout | |
| class FFN(nn.Module): | |
| def __init__(self, d_model, bidirectional=True, dropout=0): | |
| super(FFN, self).__init__() | |
| self.gru = GRU(d_model, d_model*2, 1, bidirectional=bidirectional) | |
| if bidirectional: | |
| self.linear = Linear(d_model*2*2, d_model) | |
| else: | |
| self.linear = Linear(d_model*2, d_model) | |
| self.dropout = Dropout(dropout) | |
| def forward(self, x): | |
| self.gru.flatten_parameters() | |
| x, _ = self.gru(x) | |
| x = F.leaky_relu(x) | |
| x = self.dropout(x) | |
| x = self.linear(x) | |
| return x | |
| class TransformerBlock(nn.Module): | |
| def __init__(self, d_model, n_heads, bidirectional=True, dropout=0): | |
| super(TransformerBlock, self).__init__() | |
| self.norm1 = LayerNorm(d_model) | |
| self.attention = MultiheadAttention(d_model, n_heads, dropout=dropout) | |
| self.dropout1 = Dropout(dropout) | |
| self.norm2 = LayerNorm(d_model) | |
| self.ffn = FFN(d_model, bidirectional=bidirectional) | |
| self.dropout2 = Dropout(dropout) | |
| self.norm3 = LayerNorm(d_model) | |
| def forward(self, x, attn_mask=None, key_padding_mask=None): | |
| xt = self.norm1(x) | |
| xt, _ = self.attention(xt, xt, xt, | |
| attn_mask=attn_mask, | |
| key_padding_mask=key_padding_mask) | |
| x = x + self.dropout1(xt) | |
| xt = self.norm2(x) | |
| xt = self.ffn(xt) | |
| x = x + self.dropout2(xt) | |
| x = self.norm3(x) | |
| return x | |
| def main(): | |
| x = torch.randn(4, 64, 401, 201) | |
| b, c, t, f = x.size() | |
| x = x.permute(0, 3, 2, 1).contiguous().view(b, f*t, c) | |
| transformer = TransformerBlock(d_model=64, n_heads=4) | |
| x = transformer(x) | |
| x = x.view(b, f, t, c).permute(0, 3, 2, 1) | |
| print(x.size()) | |
| if __name__ == '__main__': | |
| main() |