1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
|
import os.path as osp
import torch
import torch.nn.functional as F
from torch_geometric.datasets import Planetoid
from torch_geometric.explain import Explainer, GNNExplainer
from torch_geometric.nn import GCNConv
dataset = 'Cora'
path = osp.join(osp.dirname(osp.realpath(__file__)), '..', 'data', 'Planetoid')
dataset = Planetoid(path, dataset)
data = dataset[0]
class GCN(torch.nn.Module):
def __init__(self):
super().__init__()
self.conv1 = GCNConv(dataset.num_features, 16)
self.conv2 = GCNConv(16, dataset.num_classes)
def forward(self, x, edge_index):
x = F.relu(self.conv1(x, edge_index))
x = F.dropout(x, training=self.training)
x = self.conv2(x, edge_index)
return F.log_softmax(x, dim=1)
device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
model = GCN().to(device)
data = data.to(device)
optimizer = torch.optim.Adam(model.parameters(), lr=0.01, weight_decay=5e-4)
for epoch in range(1, 201):
model.train()
optimizer.zero_grad()
out = model(data.x, data.edge_index)
loss = F.nll_loss(out[data.train_mask], data.y[data.train_mask])
loss.backward()
optimizer.step()
explainer = Explainer(
model=model,
algorithm=GNNExplainer(epochs=200),
explanation_type='model',
node_mask_type='attributes',
edge_mask_type='object',
model_config=dict(
mode='multiclass_classification',
task_level='node',
return_type='log_probs',
),
)
node_index = 10
explanation = explainer(data.x, data.edge_index, index=node_index)
print(f'Generated explanations in {explanation.available_explanations}')
path = 'feature_importance.png'
explanation.visualize_feature_importance(path, top_k=10)
print(f"Feature importance plot has been saved to '{path}'")
path = 'subgraph.pdf'
explanation.visualize_graph(path)
print(f"Subgraph visualization plot has been saved to '{path}'")
|
