GNNRecom/gnnrec/hge/rhco/build_pos_graph_full.py

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2021-11-16 07:04:52 +00:00
import argparse
import random
from collections import defaultdict
import dgl
import torch
from gnnrec.hge.hgt.model import HGTFull
from gnnrec.hge.utils import set_random_seed, get_device, load_data, add_node_feat
def main():
args = parse_args()
print(args)
set_random_seed(args.seed)
device = get_device(args.device)
data, g, _, labels, predict_ntype, train_idx, val_idx, test_idx, _ = load_data(args.dataset)
g = g.to(device)
labels = labels.tolist()
train_idx = torch.cat([train_idx, val_idx])
add_node_feat(g, 'one-hot')
label_neigh = sample_label_neighbors(labels, args.num_samples) # (N, T_pos)
# List[tensor(N, T_pos)] HGT计算出的注意力权重M条元路径+一个总体
attn_pos = calc_attn_pos(g, data.num_classes, predict_ntype, args.num_samples, device, args)
# 元路径对应的正样本图
v = torch.repeat_interleave(g.nodes(predict_ntype), args.num_samples).cpu()
pos_graphs = []
for p in attn_pos[:-1]:
u = p.view(1, -1).squeeze(dim=0) # (N*T_pos,)
pos_graphs.append(dgl.graph((u, v)))
# 整体正样本图
pos = attn_pos[-1]
if args.use_label:
pos[train_idx] = label_neigh[train_idx]
u = pos.view(1, -1).squeeze(dim=0)
pos_graphs.append(dgl.graph((u, v)))
dgl.save_graphs(args.save_graph_path, pos_graphs)
print('正样本图已保存到', args.save_graph_path)
def calc_attn_pos(g, num_classes, predict_ntype, num_samples, device, args):
"""使用预训练的HGT模型计算的注意力权重选择目标顶点的正样本。"""
# 形如ABA的元路径其中A是目标顶点类型
metapaths = []
for s, e, d in g.canonical_etypes:
if d == predict_ntype:
re = next(re for rs, re, rd in g.canonical_etypes if rs == d and rd == s)
metapaths.append((re, e))
model = HGTFull(
{ntype: g.nodes[ntype].data['feat'].shape[1] for ntype in g.ntypes},
args.num_hidden, num_classes, args.num_heads, g.ntypes, g.canonical_etypes,
predict_ntype, 2, args.dropout
).to(device)
model.load_state_dict(torch.load(args.hgt_model_path, map_location=device))
# 每条元路径ABA对应一个正样本图G_ABA加一个总体正样本图G_pos
with torch.no_grad():
_ = model(g, g.ndata['feat'])
attn = [calc_attn(mp, model, g, device).t() for mp in metapaths] # List[tensor(N, N)]
pos = [torch.topk(a, num_samples)[1] for a in attn] # List[tensor(N, T_pos)]
pos.append(torch.topk(sum(attn), num_samples)[1])
return [p.cpu() for p in pos]
def calc_attn(metapath, model, g, device):
"""计算通过指定元路径与目标顶点连接的同类型顶点的注意力权重。"""
re, e = metapath
s, _, d = g.to_canonical_etype(re) # s是目标顶点类型, d是中间顶点类型
a0 = torch.zeros(g.num_nodes(s), g.num_nodes(d), device=device)
a0[g.edges(etype=re)] = model.layers[0].conv.mods[re].attn.mean(dim=1)
a1 = torch.zeros(g.num_nodes(d), g.num_nodes(s), device=device)
a1[g.edges(etype=e)] = model.layers[1].conv.mods[e].attn.mean(dim=1)
return torch.matmul(a0, a1) # (N, N)
def sample_label_neighbors(labels, num_samples):
"""为每个顶点采样相同标签的邻居。"""
label2id = defaultdict(list)
for i, y in enumerate(labels):
label2id[y].append(i)
return torch.tensor([random.sample(label2id[y], num_samples) for y in labels])
def parse_args():
parser = argparse.ArgumentParser(description='使用预训练的HGT计算的注意力权重构造正样本图(full-batch)')
parser.add_argument('--seed', type=int, default=0, help='随机数种子')
parser.add_argument('--device', type=int, default=0, help='GPU设备')
parser.add_argument('--dataset', choices=['acm', 'dblp'], default='acm', help='数据集')
parser.add_argument('--num-hidden', type=int, default=512, help='隐藏层维数')
parser.add_argument('--num-heads', type=int, default=8, help='注意力头数')
parser.add_argument('--dropout', type=float, default=0.5, help='Dropout概率')
parser.add_argument('--num-samples', type=int, default=5, help='每个顶点采样的正样本数量')
parser.add_argument('--use-label', action='store_true', help='训练集使用真实标签')
parser.add_argument('hgt_model_path', help='预训练的HGT模型保存路径')
parser.add_argument('save_graph_path', help='正样本图保存路径')
args = parser.parse_args()
return args
if __name__ == '__main__':
main()