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2019-11-04 12:11:53 +08:00

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Python

"""
This code was modified from the GCN implementation in DGL examples.
Simplifying Graph Convolutional Networks
Paper: https://arxiv.org/abs/1902.07153
Code: https://github.com/Tiiiger/SGC
SGC implementation in DGL.
"""
import argparse, time, math
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import dgl.function as fn
from dgl import DGLGraph
from dgl.data import register_data_args, load_data
from dgl.nn.pytorch.conv import SGConv
def normalize(h):
return (h-h.mean(0))/h.std(0)
def evaluate(model, features, graph, labels, mask):
model.eval()
with torch.no_grad():
logits = model(graph, features)[mask] # only compute the evaluation set
labels = labels[mask]
_, indices = torch.max(logits, dim=1)
correct = torch.sum(indices == labels)
return correct.item() * 1.0 / len(labels)
def main(args):
# load and preprocess dataset
args.dataset = "reddit-self-loop"
data = load_data(args)
features = torch.FloatTensor(data.features)
labels = torch.LongTensor(data.labels)
if hasattr(torch, 'BoolTensor'):
train_mask = torch.BoolTensor(data.train_mask)
val_mask = torch.BoolTensor(data.val_mask)
test_mask = torch.BoolTensor(data.test_mask)
else:
train_mask = torch.ByteTensor(data.train_mask)
val_mask = torch.ByteTensor(data.val_mask)
test_mask = torch.ByteTensor(data.test_mask)
in_feats = features.shape[1]
n_classes = data.num_labels
n_edges = data.graph.number_of_edges()
print("""----Data statistics------'
#Edges %d
#Classes %d
#Train samples %d
#Val samples %d
#Test samples %d""" %
(n_edges, n_classes,
train_mask.int().sum().item(),
val_mask.int().sum().item(),
test_mask.int().sum().item()))
if args.gpu < 0:
cuda = False
else:
cuda = True
torch.cuda.set_device(args.gpu)
features = features.cuda()
labels = labels.cuda()
train_mask = train_mask.cuda()
val_mask = val_mask.cuda()
test_mask = test_mask.cuda()
# graph preprocess and calculate normalization factor
g = DGLGraph(data.graph)
n_edges = g.number_of_edges()
# normalization
degs = g.in_degrees().float()
norm = torch.pow(degs, -0.5)
norm[torch.isinf(norm)] = 0
if cuda: norm = norm.cuda()
g.ndata['norm'] = norm.unsqueeze(1)
# create SGC model
model = SGConv(in_feats, n_classes, k=2, cached=True, bias=True, norm=normalize)
if args.gpu >= 0:
model = model.cuda()
# use optimizer
optimizer = torch.optim.LBFGS(model.parameters())
# define loss closure
def closure():
optimizer.zero_grad()
output = model(g, features)[train_mask]
loss_train = F.cross_entropy(output, labels[train_mask])
loss_train.backward()
return loss_train
# initialize graph
for epoch in range(args.n_epochs):
model.train()
optimizer.step(closure)
acc = evaluate(model, features, g, labels, test_mask)
print("Test Accuracy {:.4f}".format(acc))
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='SGC')
register_data_args(parser)
parser.add_argument("--gpu", type=int, default=-1,
help="gpu")
parser.add_argument("--bias", action='store_true', default=False,
help="flag to use bias")
parser.add_argument("--n-epochs", type=int, default=2,
help="number of training epochs")
args = parser.parse_args()
print(args)
main(args)