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文件
Mufei Li 2758c24955 [NN] Fix GCN module (#99)
1. Update `examples/pytorch/gcn` and `python/dgl/nn/pytorch` based on the latest APIs
2. Add full support for dropout in `examples/pytorch/gcn` and `python/dgl/nn/pytorch`
3. Rename `GCN` class in `python/dgl/nn/pytorch` to be `GraphConvolutionLayer` class
4. Make node field an argument that can be configured by users in GraphConvolutionLayer

Note that adjacency normalization has not been supported yet in the examples.
2018-10-28 04:35:33 +08:00

71 行
2.2 KiB
Python

"""
Semi-Supervised Classification with Graph Convolutional Networks
Paper: https://arxiv.org/abs/1609.02907
Code: https://github.com/tkipf/gcn
GCN with SPMV specialization.
"""
import torch.nn as nn
from ... import function as fn
from ...base import ALL, is_all
class NodeUpdateModule(nn.Module):
def __init__(self, node_field, in_feats, out_feats, activation=None):
super(NodeUpdateModule, self).__init__()
self.node_field = node_field
self.linear = nn.Linear(in_feats, out_feats)
self.activation = activation
def forward(self, node):
h = self.linear(node[self.node_field])
if self.activation:
h = self.activation(h)
return {self.node_field: h}
class GraphConvolutionLayer(nn.Module):
"""Single graph convolution layer as in https://arxiv.org/abs/1609.02907."""
def __init__(self,
node_field,
in_feats,
out_feats,
activation,
dropout=0):
"""
node_filed: hashable keys for node features, e.g. 'h'
msg_field: hashable keys for message features, e.g. 'm'. In GCN, this is
just AH, where A is the adjacency matrix and H is current node features.
"""
super(GraphConvolutionLayer, self).__init__()
self.node_field = node_field
if dropout:
self.dropout = nn.Dropout(p=dropout)
else:
self.dropout = 0.
# input layer
self.update_func = NodeUpdateModule(node_field, in_feats, out_feats,
activation)
def forward(self, g, u=ALL, v=ALL):
if self.dropout:
g.apply_nodes(u, apply_node_func=
lambda node: {self.node_field: self.dropout(node[self.node_field])})
if is_all(u) and is_all(v):
g.update_all(fn.copy_src(src=self.node_field, out='m'),
fn.sum(msg='m', out=self.node_field),
self.update_func)
else:
g.send_and_recv(u, v,
fn.copy_src(src=self.node_field, out='m'),
fn.sum(msg='m', out=self.node_field),
self.update_func)
return g