项目文件夹

文件
2019-11-04 12:11:53 +08:00

274 行
9.4 KiB
Python

import argparse, time, math
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from functools import partial
import dgl
import dgl.function as fn
from dgl import DGLGraph
from dgl.data import register_data_args, load_data
class NodeUpdate(nn.Module):
def __init__(self, in_feats, out_feats, activation=None, test=False, concat=False):
super(NodeUpdate, self).__init__()
self.linear = nn.Linear(in_feats, out_feats)
self.activation = activation
self.concat = concat
self.test = test
def forward(self, node):
h = node.data['h']
if self.test:
h = h * node.data['norm']
h = self.linear(h)
# skip connection
if self.concat:
h = torch.cat((h, self.activation(h)), dim=1)
elif self.activation:
h = self.activation(h)
return {'activation': h}
class GCNSampling(nn.Module):
def __init__(self,
in_feats,
n_hidden,
n_classes,
n_layers,
activation,
dropout):
super(GCNSampling, self).__init__()
self.n_layers = n_layers
if dropout != 0:
self.dropout = nn.Dropout(p=dropout)
else:
self.dropout = None
self.layers = nn.ModuleList()
# input layer
skip_start = (0 == n_layers-1)
self.layers.append(NodeUpdate(in_feats, n_hidden, activation, concat=skip_start))
# hidden layers
for i in range(1, n_layers):
skip_start = (i == n_layers-1)
self.layers.append(NodeUpdate(n_hidden, n_hidden, activation, concat=skip_start))
# output layer
self.layers.append(NodeUpdate(2*n_hidden, n_classes))
def forward(self, nf):
nf.layers[0].data['activation'] = nf.layers[0].data['features']
for i, layer in enumerate(self.layers):
h = nf.layers[i].data.pop('activation')
if self.dropout:
h = self.dropout(h)
nf.layers[i].data['h'] = h
nf.block_compute(i,
fn.copy_src(src='h', out='m'),
lambda node : {'h': node.mailbox['m'].mean(dim=1)},
layer)
h = nf.layers[-1].data.pop('activation')
return h
class GCNInfer(nn.Module):
def __init__(self,
in_feats,
n_hidden,
n_classes,
n_layers,
activation):
super(GCNInfer, self).__init__()
self.n_layers = n_layers
self.layers = nn.ModuleList()
# input layer
skip_start = (0 == n_layers-1)
self.layers.append(NodeUpdate(in_feats, n_hidden, activation, test=True, concat=skip_start))
# hidden layers
for i in range(1, n_layers):
skip_start = (i == n_layers-1)
self.layers.append(NodeUpdate(n_hidden, n_hidden, activation, test=True, concat=skip_start))
# output layer
self.layers.append(NodeUpdate(2*n_hidden, n_classes, test=True))
def forward(self, nf):
nf.layers[0].data['activation'] = nf.layers[0].data['features']
for i, layer in enumerate(self.layers):
h = nf.layers[i].data.pop('activation')
nf.layers[i].data['h'] = h
nf.block_compute(i,
fn.copy_src(src='h', out='m'),
fn.sum(msg='m', out='h'),
layer)
h = nf.layers[-1].data.pop('activation')
return h
def main(args):
# load and preprocess dataset
data = load_data(args)
if args.self_loop and not args.dataset.startswith('reddit'):
data.graph.add_edges_from([(i,i) for i in range(len(data.graph))])
train_nid = np.nonzero(data.train_mask)[0].astype(np.int64)
test_nid = np.nonzero(data.test_mask)[0].astype(np.int64)
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()
n_train_samples = train_mask.int().sum().item()
n_val_samples = val_mask.int().sum().item()
n_test_samples = test_mask.int().sum().item()
print("""----Data statistics------'
#Edges %d
#Classes %d
#Train samples %d
#Val samples %d
#Test samples %d""" %
(n_edges, n_classes,
n_train_samples,
n_val_samples,
n_test_samples))
# create GCN model
g = DGLGraph(data.graph, readonly=True)
norm = 1. / g.in_degrees().float().unsqueeze(1)
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()
norm = norm.cuda()
g.ndata['features'] = features
num_neighbors = args.num_neighbors
g.ndata['norm'] = norm
model = GCNSampling(in_feats,
args.n_hidden,
n_classes,
args.n_layers,
F.relu,
args.dropout)
if cuda:
model.cuda()
loss_fcn = nn.CrossEntropyLoss()
infer_model = GCNInfer(in_feats,
args.n_hidden,
n_classes,
args.n_layers,
F.relu)
if cuda:
infer_model.cuda()
# use optimizer
optimizer = torch.optim.Adam(model.parameters(),
lr=args.lr,
weight_decay=args.weight_decay)
# initialize graph
dur = []
for epoch in range(args.n_epochs):
for nf in dgl.contrib.sampling.NeighborSampler(g, args.batch_size,
args.num_neighbors,
neighbor_type='in',
shuffle=True,
num_workers=32,
num_hops=args.n_layers+1,
seed_nodes=train_nid):
nf.copy_from_parent()
model.train()
# forward
pred = model(nf)
batch_nids = nf.layer_parent_nid(-1).to(device=pred.device, dtype=torch.long)
batch_labels = labels[batch_nids]
loss = loss_fcn(pred, batch_labels)
optimizer.zero_grad()
loss.backward()
optimizer.step()
for infer_param, param in zip(infer_model.parameters(), model.parameters()):
infer_param.data.copy_(param.data)
num_acc = 0.
for nf in dgl.contrib.sampling.NeighborSampler(g, args.test_batch_size,
g.number_of_nodes(),
neighbor_type='in',
num_workers=32,
num_hops=args.n_layers+1,
seed_nodes=test_nid):
nf.copy_from_parent()
infer_model.eval()
with torch.no_grad():
pred = infer_model(nf)
batch_nids = nf.layer_parent_nid(-1).to(device=pred.device, dtype=torch.long)
batch_labels = labels[batch_nids]
num_acc += (pred.argmax(dim=1) == batch_labels).sum().cpu().item()
print("Test Accuracy {:.4f}". format(num_acc/n_test_samples))
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='GCN')
register_data_args(parser)
parser.add_argument("--dropout", type=float, default=0.5,
help="dropout probability")
parser.add_argument("--gpu", type=int, default=-1,
help="gpu")
parser.add_argument("--lr", type=float, default=3e-2,
help="learning rate")
parser.add_argument("--n-epochs", type=int, default=200,
help="number of training epochs")
parser.add_argument("--batch-size", type=int, default=1000,
help="batch size")
parser.add_argument("--test-batch-size", type=int, default=1000,
help="test batch size")
parser.add_argument("--num-neighbors", type=int, default=3,
help="number of neighbors to be sampled")
parser.add_argument("--n-hidden", type=int, default=16,
help="number of hidden gcn units")
parser.add_argument("--n-layers", type=int, default=1,
help="number of hidden gcn layers")
parser.add_argument("--self-loop", action='store_true',
help="graph self-loop (default=False)")
parser.add_argument("--weight-decay", type=float, default=5e-4,
help="Weight for L2 loss")
args = parser.parse_args()
print(args)
main(args)