78 lines
2.0 KiB
Python
78 lines
2.0 KiB
Python
"""
|
|
Graph Attention Networks in DGL using SPMV optimization.
|
|
References
|
|
----------
|
|
Paper: https://arxiv.org/abs/1710.10903
|
|
Author's code: https://github.com/PetarV-/GAT
|
|
Pytorch implementation: https://github.com/Diego999/pyGAT
|
|
"""
|
|
|
|
import mxnet.gluon.nn as nn
|
|
|
|
from dgl.nn.mxnet.conv import GATConv
|
|
|
|
|
|
class GAT(nn.Block):
|
|
def __init__(
|
|
self,
|
|
g,
|
|
num_layers,
|
|
in_dim,
|
|
num_hidden,
|
|
num_classes,
|
|
heads,
|
|
activation,
|
|
feat_drop,
|
|
attn_drop,
|
|
alpha,
|
|
residual,
|
|
):
|
|
super(GAT, self).__init__()
|
|
self.g = g
|
|
self.num_layers = num_layers
|
|
self.gat_layers = []
|
|
self.activation = activation
|
|
# input projection (no residual)
|
|
self.gat_layers.append(
|
|
GATConv(
|
|
in_dim, num_hidden, heads[0], feat_drop, attn_drop, alpha, False
|
|
)
|
|
)
|
|
# hidden layers
|
|
for l in range(1, num_layers):
|
|
# due to multi-head, the in_dim = num_hidden * num_heads
|
|
self.gat_layers.append(
|
|
GATConv(
|
|
num_hidden * heads[l - 1],
|
|
num_hidden,
|
|
heads[l],
|
|
feat_drop,
|
|
attn_drop,
|
|
alpha,
|
|
residual,
|
|
)
|
|
)
|
|
# output projection
|
|
self.gat_layers.append(
|
|
GATConv(
|
|
num_hidden * heads[-2],
|
|
num_classes,
|
|
heads[-1],
|
|
feat_drop,
|
|
attn_drop,
|
|
alpha,
|
|
residual,
|
|
)
|
|
)
|
|
for i, layer in enumerate(self.gat_layers):
|
|
self.register_child(layer, "gat_layer_{}".format(i))
|
|
|
|
def forward(self, inputs):
|
|
h = inputs
|
|
for l in range(self.num_layers):
|
|
h = self.gat_layers[l](self.g, h).flatten()
|
|
h = self.activation(h)
|
|
# output projection
|
|
logits = self.gat_layers[-1](self.g, h).mean(1)
|
|
return logits
|