Files
2026-07-13 13:35:51 +08:00

279 lines
8.4 KiB
Python

import argparse
import dgl
import torch as th
import torch.optim as optim
from model_sampling import _l1_dist, CAREGNN, CARESampler
from sklearn.metrics import recall_score, roc_auc_score
from torch.nn.functional import softmax
from utils import EarlyStopping
def evaluate(model, loss_fn, dataloader, device="cpu"):
loss = 0
auc = 0
recall = 0
num_blocks = 0
for input_nodes, output_nodes, blocks in dataloader:
blocks = [b.to(device) for b in blocks]
feature = blocks[0].srcdata["feature"]
label = blocks[-1].dstdata["label"]
logits_gnn, logits_sim = model(blocks, feature)
# compute loss
loss += (
loss_fn(logits_gnn, label).item()
+ args.sim_weight * loss_fn(logits_sim, label).item()
)
recall += recall_score(
label.cpu(), logits_gnn.argmax(dim=1).detach().cpu()
)
auc += roc_auc_score(
label.cpu(), softmax(logits_gnn, dim=1)[:, 1].detach().cpu()
)
num_blocks += 1
return recall / num_blocks, auc / num_blocks, loss / num_blocks
def main(args):
# Step 1: Prepare graph data and retrieve train/validation/test index ============================= #
# Load dataset
dataset = dgl.data.FraudDataset(args.dataset, train_size=0.4)
graph = dataset[0]
num_classes = dataset.num_classes
# check cuda
if args.gpu >= 0 and th.cuda.is_available():
device = "cuda:{}".format(args.gpu)
args.num_workers = 0
else:
device = "cpu"
# retrieve labels of ground truth
labels = graph.ndata["label"].to(device)
# Extract node features
feat = graph.ndata["feature"].to(device)
layers_feat = feat.expand(args.num_layers, -1, -1)
# retrieve masks for train/validation/test
train_mask = graph.ndata["train_mask"]
val_mask = graph.ndata["val_mask"]
test_mask = graph.ndata["test_mask"]
train_idx = th.nonzero(train_mask, as_tuple=False).squeeze(1).to(device)
val_idx = th.nonzero(val_mask, as_tuple=False).squeeze(1).to(device)
test_idx = th.nonzero(test_mask, as_tuple=False).squeeze(1).to(device)
# Reinforcement learning module only for positive training nodes
rl_idx = th.nonzero(
train_mask.to(device) & labels.bool(), as_tuple=False
).squeeze(1)
graph = graph.to(device)
# Step 2: Create model =================================================================== #
model = CAREGNN(
in_dim=feat.shape[-1],
num_classes=num_classes,
hid_dim=args.hid_dim,
num_layers=args.num_layers,
activation=th.tanh,
step_size=args.step_size,
edges=graph.canonical_etypes,
)
model = model.to(device)
# Step 3: Create training components ===================================================== #
_, cnt = th.unique(labels, return_counts=True)
loss_fn = th.nn.CrossEntropyLoss(weight=1 / cnt)
optimizer = optim.Adam(
model.parameters(), lr=args.lr, weight_decay=args.weight_decay
)
if args.early_stop:
stopper = EarlyStopping(patience=100)
# Step 4: training epochs =============================================================== #
for epoch in range(args.max_epoch):
# calculate the distance of each edges and sample based on the distance
dists = []
p = []
for i in range(args.num_layers):
dist = {}
graph.ndata["nd"] = th.tanh(model.layers[i].MLP(layers_feat[i]))
for etype in graph.canonical_etypes:
graph.apply_edges(_l1_dist, etype=etype)
dist[etype] = graph.edges[etype].data.pop("ed").detach().cpu()
dists.append(dist)
p.append(model.layers[i].p)
graph.ndata.pop("nd")
sampler = CARESampler(p, dists, args.num_layers)
# train
model.train()
tr_loss = 0
tr_recall = 0
tr_auc = 0
tr_blk = 0
train_dataloader = dgl.dataloading.DataLoader(
graph,
train_idx,
sampler,
batch_size=args.batch_size,
shuffle=True,
drop_last=False,
num_workers=args.num_workers,
)
for input_nodes, output_nodes, blocks in train_dataloader:
blocks = [b.to(device) for b in blocks]
train_feature = blocks[0].srcdata["feature"]
train_label = blocks[-1].dstdata["label"]
logits_gnn, logits_sim = model(blocks, train_feature)
# compute loss
blk_loss = loss_fn(
logits_gnn, train_label
) + args.sim_weight * loss_fn(logits_sim, train_label)
tr_loss += blk_loss.item()
tr_recall += recall_score(
train_label.cpu(), logits_gnn.argmax(dim=1).detach().cpu()
)
tr_auc += roc_auc_score(
train_label.cpu(),
softmax(logits_gnn, dim=1)[:, 1].detach().cpu(),
)
tr_blk += 1
# backward
optimizer.zero_grad()
blk_loss.backward()
optimizer.step()
# Reinforcement learning module
model.RLModule(graph, epoch, rl_idx, dists)
# validation
model.eval()
val_dataloader = dgl.dataloading.DataLoader(
graph,
val_idx,
sampler,
batch_size=args.batch_size,
shuffle=True,
drop_last=False,
num_workers=args.num_workers,
)
val_recall, val_auc, val_loss = evaluate(
model, loss_fn, val_dataloader, device
)
# Print out performance
print(
"In epoch {}, Train Recall: {:.4f} | Train AUC: {:.4f} | Train Loss: {:.4f}; "
"Valid Recall: {:.4f} | Valid AUC: {:.4f} | Valid loss: {:.4f}".format(
epoch,
tr_recall / tr_blk,
tr_auc / tr_blk,
tr_loss / tr_blk,
val_recall,
val_auc,
val_loss,
)
)
if args.early_stop:
if stopper.step(val_auc, model):
break
# Test with mini batch after all epoch
model.eval()
if args.early_stop:
model.load_state_dict(th.load("es_checkpoint.pt"))
test_dataloader = dgl.dataloading.DataLoader(
graph,
test_idx,
sampler,
batch_size=args.batch_size,
shuffle=True,
drop_last=False,
num_workers=args.num_workers,
)
test_recall, test_auc, test_loss = evaluate(
model, loss_fn, test_dataloader, device
)
print(
"Test Recall: {:.4f} | Test AUC: {:.4f} | Test loss: {:.4f}".format(
test_recall, test_auc, test_loss
)
)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="GCN-based Anti-Spam Model")
parser.add_argument(
"--dataset",
type=str,
default="amazon",
help="DGL dataset for this model (yelp, or amazon)",
)
parser.add_argument(
"--gpu", type=int, default=-1, help="GPU index. Default: -1, using CPU."
)
parser.add_argument(
"--hid_dim", type=int, default=64, help="Hidden layer dimension"
)
parser.add_argument(
"--num_layers", type=int, default=1, help="Number of layers"
)
parser.add_argument(
"--batch_size", type=int, default=256, help="Size of mini-batch"
)
parser.add_argument(
"--max_epoch",
type=int,
default=30,
help="The max number of epochs. Default: 30",
)
parser.add_argument(
"--lr", type=float, default=0.01, help="Learning rate. Default: 0.01"
)
parser.add_argument(
"--weight_decay",
type=float,
default=0.001,
help="Weight decay. Default: 0.001",
)
parser.add_argument(
"--step_size",
type=float,
default=0.02,
help="RL action step size (lambda 2). Default: 0.02",
)
parser.add_argument(
"--sim_weight",
type=float,
default=2,
help="Similarity loss weight (lambda 1). Default: 0.001",
)
parser.add_argument(
"--num_workers", type=int, default=4, help="Number of node dataloader"
)
parser.add_argument(
"--early-stop",
action="store_true",
default=False,
help="indicates whether to use early stop",
)
args = parser.parse_args()
th.manual_seed(717)
print(args)
main(args)