File size: 4,800 Bytes
2ab60a1
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
import torch
from torch import nn
from torch_geometric.nn import MessagePassing


class CustomTransformer(nn.Module):
    def __init__(self, feat_dim, nhead, num_encoder_layers, dim_feedforward, dropout, first_seq=1, second_seq=1):
        super(CustomTransformer, self).__init__()
        self.seq_len = first_seq + second_seq + 2
        self.first_seq = first_seq
        self.second_seq = second_seq

        encoder_layer = nn.TransformerEncoderLayer(d_model=feat_dim, nhead=nhead,
                                                   dim_feedforward=dim_feedforward,
                                                   dropout=dropout, batch_first=True)
        self.transformer_encoder = nn.TransformerEncoder(encoder_layer, num_layers=num_encoder_layers,
                                                         enable_nested_tensor=False)

        self.cls_token_param = nn.Parameter(torch.ones(1, 1, feat_dim))
        self.sep_token_param = nn.Parameter(torch.zeros(1, 1, feat_dim))

        self.pos_param = nn.Parameter(torch.zeros(1, self.seq_len, feat_dim))

    def forward(self, *x):
        # x1: (Be (!), H) | x1: (Be, H)
        # x2: (Be, H)     | x2: (Be, H)
        # x3 : --         | x3: (Be, H)

        first_seq = [x.unsqueeze(1) for x in x[:self.first_seq]]  # (Be, 1, H)
        second_seq = [x.unsqueeze(1) for x in x[self.first_seq:]]  # (Be, 1, H)

        cls_token = self.cls_token_param.expand(first_seq[0].size(0), -1, -1)
        sep_token = self.sep_token_param.expand(first_seq[0].size(0), -1, -1)

        x = torch.cat([cls_token] + first_seq + [sep_token] + second_seq, dim=1)
        x += self.pos_param

        x = self.transformer_encoder(x)
        return x[:, 0, :]


class GNNTransformModel(MessagePassing):
    def __init__(self, num_node_features, num_edge_features, dropout_rate=.1, hid_dim=128):
        super(GNNTransformModel, self).__init__(aggr='add')

        self.node_encoder = nn.Sequential(
            nn.Linear(num_node_features, hid_dim),
            nn.Linear(hid_dim, hid_dim),
            nn.LayerNorm(hid_dim),
        )
        self.edge_encoder = nn.Sequential(
            nn.Linear(num_edge_features, hid_dim),
            nn.Linear(hid_dim, hid_dim),
            nn.LayerNorm(hid_dim),
        )

        self.node_decoder = nn.Linear(hid_dim, num_node_features)
        self.edge_decoder = nn.Linear(hid_dim, num_edge_features)

        self.node_message_passing = CustomTransformer(
            hid_dim, 4, 4, hid_dim, dropout_rate,
            first_seq=1
        )
        self.edge_message_passing = CustomTransformer(
            hid_dim, 4, 4, hid_dim, dropout_rate,
            first_seq=2
        )

        # self.node_message_passing = nn.Sequential(
        #     nn.Linear(hid_dim * 2, hid_dim),
        #     nn.LeakyReLU(),
        #     nn.Dropout(p=dropout_rate),
        #     nn.Linear(hid_dim, hid_dim),
        #     nn.LeakyReLU(),
        #     nn.Dropout(p=dropout_rate),
        #     nn.Linear(hid_dim, hid_dim),
        #     nn.LeakyReLU(),
        # )

        # self.edge_message_passing = nn.Sequential(
        #     nn.Linear(hid_dim * 3, hid_dim),
        #     nn.LeakyReLU(),
        #     nn.Dropout(p=dropout_rate),
        #     nn.Linear(hid_dim, hid_dim),
        #     nn.LeakyReLU(),
        #     nn.Dropout(p=dropout_rate),
        #     nn.Linear(hid_dim, hid_dim),
        #     nn.LeakyReLU(),
        # )

    def forward(self, x, edge_index, edge_attr):
        # x: (Bn, N) Bn ~ 4978
        # edge_attr: (Be, E) Be ~ 10708
        # edge_index: (2, Be)

        x = self.node_encoder(x)  # (Bn, H)
        edge_attr = self.edge_encoder(edge_attr) if len(edge_attr) > 0 else edge_attr  # (Be, H)

        # Handling graphs with no edges
        if len(edge_index) > 0 and edge_index.shape[1] > 0:
            x = self.propagate(edge_index, x=x, edge_attr=edge_attr)
            edge_attr = self.edge_updater(edge_index, x=x, edge_attr=edge_attr) if len(edge_attr) > 0 else edge_attr

        out_node_features = self.node_decoder(x)
        out_edge_features = self.edge_decoder(edge_attr) if len(edge_attr) > 0 else edge_attr

        return out_node_features, out_edge_features

    def message(self, x_j, edge_attr):
        # x_i: --
        # x_j: (Be (!), H)
        # edge_attr: (Be, H)

        return self.node_message_passing(x_j, edge_attr)

    def edge_update(self, x_i, x_j, edge_attr):
        # x_i: (Be, H)
        # x_j: (Be, H)
        # edge_attr: (Be, H)

        return self.edge_message_passing(x_i, x_j, edge_attr)

    def update(self, aggr_out):
        # Only for nodes
        # aggr_out: (Bn, H)

        return aggr_out