Class MotionLenEstimatorBiGRU

text2motion/datasets/evaluator_models.py:389–438

class MotionLenEstimatorBiGRU(nn.Module):
    def __init__(self, word_size, pos_size, hidden_size, output_size):
        super(MotionLenEstimatorBiGRU, self).__init__()

        self.pos_emb = nn.Linear(pos_size, word_size)
        self.input_emb = nn.Linear(word_size, hidden_size)
        self.gru = nn.GRU(hidden_size, hidden_size, batch_first=True, bidirectional=True)
        nd = 512
        self.output = nn.Sequential(
            nn.Linear(hidden_size*2, nd),
            nn.LayerNorm(nd),
            nn.LeakyReLU(0.2, inplace=True),

            nn.Linear(nd, nd // 2),
            nn.LayerNorm(nd // 2),
            nn.LeakyReLU(0.2, inplace=True),

            nn.Linear(nd // 2, nd // 4),
            nn.LayerNorm(nd // 4),
            nn.LeakyReLU(0.2, inplace=True),

            nn.Linear(nd // 4, output_size)
        )
        # self.linear2 = nn.Linear(hidden_size, output_size)

        self.input_emb.apply(init_weight)
        self.pos_emb.apply(init_weight)
        self.output.apply(init_weight)
        # self.linear2.apply(init_weight)
        # self.batch_size = batch_size
        self.hidden_size = hidden_size
        self.hidden = nn.Parameter(torch.randn((2, 1, self.hidden_size), requires_grad=True))

    # input(batch_size, seq_len, dim)
    def forward(self, word_embs, pos_onehot, cap_lens):
        num_samples = word_embs.shape[0]

        pos_embs = self.pos_emb(pos_onehot)
        inputs = word_embs + pos_embs
        input_embs = self.input_emb(inputs)
        hidden = self.hidden.repeat(1, num_samples, 1)

        cap_lens = cap_lens.data.tolist()
        emb = pack_padded_sequence(input_embs, cap_lens, batch_first=True)

        gru_seq, gru_last = self.gru(emb, hidden)

        gru_last = torch.cat([gru_last[0], gru_last[1]], dim=-1)

        return self.output(gru_last)