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

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Python

""" Code adapted from https://github.com/kavehhassani/mvgrl """
import os
import re
from collections import Counter
import dgl
import networkx as nx
import numpy as np
import torch as th
from dgl.data import DGLDataset
from scipy.linalg import fractional_matrix_power, inv
""" Compute Personalized Page Ranking"""
def compute_ppr(graph: nx.Graph, alpha=0.2, self_loop=True):
a = nx.convert_matrix.to_numpy_array(graph)
if self_loop:
a = a + np.eye(a.shape[0]) # A^ = A + I_n
d = np.diag(np.sum(a, 1)) # D^ = Sigma A^_ii
dinv = fractional_matrix_power(d, -0.5) # D^(-1/2)
at = np.matmul(np.matmul(dinv, a), dinv) # A~ = D^(-1/2) x A^ x D^(-1/2)
return alpha * inv(
(np.eye(a.shape[0]) - (1 - alpha) * at)
) # a(I_n-(1-a)A~)^-1
def download(dataset, datadir):
os.makedirs(datadir)
url = "https://ls11-www.cs.tu-dortmund.de/people/morris/graphkerneldatasets/{0}.zip".format(
dataset
)
zipfile = os.path.basename(url)
os.system("wget {0}; unzip {1}".format(url, zipfile))
os.system("mv {0}/* {1}".format(dataset, datadir))
os.system("rm -r {0}".format(dataset))
os.system("rm {0}".format(zipfile))
def process(dataset):
src = os.path.join(os.path.dirname(__file__), "data")
prefix = os.path.join(src, dataset, dataset)
# assign each node to the corresponding graph
graph_node_dict = {}
with open("{0}_graph_indicator.txt".format(prefix), "r") as f:
for idx, line in enumerate(f):
graph_node_dict[idx + 1] = int(line.strip("\n"))
node_labels = []
if os.path.exists("{0}_node_labels.txt".format(prefix)):
with open("{0}_node_labels.txt".format(prefix), "r") as f:
for line in f:
node_labels += [int(line.strip("\n")) - 1]
num_unique_node_labels = max(node_labels) + 1
else:
print("No node labels")
node_attrs = []
if os.path.exists("{0}_node_attributes.txt".format(prefix)):
with open("{0}_node_attributes.txt".format(prefix), "r") as f:
for line in f:
node_attrs.append(
np.array(
[
float(attr)
for attr in re.split("[,\s]+", line.strip("\s\n"))
if attr
],
dtype=float,
)
)
else:
print("No node attributes")
graph_labels = []
unique_labels = set()
with open("{0}_graph_labels.txt".format(prefix), "r") as f:
for line in f:
val = int(line.strip("\n"))
if val not in unique_labels:
unique_labels.add(val)
graph_labels.append(val)
label_idx_dict = {val: idx for idx, val in enumerate(unique_labels)}
graph_labels = np.array([label_idx_dict[l] for l in graph_labels])
adj_list = {idx: [] for idx in range(1, len(graph_labels) + 1)}
index_graph = {idx: [] for idx in range(1, len(graph_labels) + 1)}
with open("{0}_A.txt".format(prefix), "r") as f:
for line in f:
u, v = tuple(map(int, line.strip("\n").split(",")))
adj_list[graph_node_dict[u]].append((u, v))
index_graph[graph_node_dict[u]] += [u, v]
for k in index_graph.keys():
index_graph[k] = [u - 1 for u in set(index_graph[k])]
graphs, pprs = [], []
for idx in range(1, 1 + len(adj_list)):
graph = nx.from_edgelist(adj_list[idx])
graph.graph["label"] = graph_labels[idx - 1]
for u in graph.nodes():
if len(node_labels) > 0:
node_label_one_hot = [0] * num_unique_node_labels
node_label = node_labels[u - 1]
node_label_one_hot[node_label] = 1
graph.nodes[u]["label"] = node_label_one_hot
if len(node_attrs) > 0:
graph.nodes[u]["feat"] = node_attrs[u - 1]
if len(node_attrs) > 0:
graph.graph["feat_dim"] = node_attrs[0].shape[0]
# relabeling
mapping = {}
for node_idx, node in enumerate(graph.nodes()):
mapping[node] = node_idx
graphs.append(nx.relabel_nodes(graph, mapping))
pprs.append(compute_ppr(graph, alpha=0.2))
if "feat_dim" in graphs[0].graph:
pass
else:
max_deg = max([max(dict(graph.degree).values()) for graph in graphs])
for graph in graphs:
for u in graph.nodes(data=True):
f = np.zeros(max_deg + 1)
f[graph.degree[u[0]]] = 1.0
if "label" in u[1]:
f = np.concatenate(
(np.array(u[1]["label"], dtype=float), f)
)
graph.nodes[u[0]]["feat"] = f
return graphs, pprs
def load(dataset):
basedir = os.path.dirname(os.path.abspath(__file__))
datadir = os.path.join(basedir, "data", dataset)
if not os.path.exists(datadir):
download(dataset, datadir)
graphs, diff = process(dataset)
feat, adj, labels = [], [], []
for idx, graph in enumerate(graphs):
adj.append(nx.to_numpy_array(graph))
labels.append(graph.graph["label"])
feat.append(
np.array(list(nx.get_node_attributes(graph, "feat").values()))
)
adj, diff, feat, labels = (
np.array(adj),
np.array(diff),
np.array(feat),
np.array(labels),
)
np.save(f"{datadir}/adj.npy", adj)
np.save(f"{datadir}/diff.npy", diff)
np.save(f"{datadir}/feat.npy", feat)
np.save(f"{datadir}/labels.npy", labels)
else:
adj = np.load(f"{datadir}/adj.npy", allow_pickle=True)
diff = np.load(f"{datadir}/diff.npy", allow_pickle=True)
feat = np.load(f"{datadir}/feat.npy", allow_pickle=True)
labels = np.load(f"{datadir}/labels.npy", allow_pickle=True)
n_graphs = adj.shape[0]
graphs = []
diff_graphs = []
lbls = []
for i in range(n_graphs):
a = adj[i]
edge_indexes = a.nonzero()
graph = dgl.graph(edge_indexes)
graph = graph.add_self_loop()
graph.ndata["feat"] = th.tensor(feat[i]).float()
diff_adj = diff[i]
diff_indexes = diff_adj.nonzero()
diff_weight = th.tensor(diff_adj[diff_indexes]).float()
diff_graph = dgl.graph(diff_indexes)
diff_graph.edata["edge_weight"] = diff_weight
label = labels[i]
graphs.append(graph)
diff_graphs.append(diff_graph)
lbls.append(label)
labels = th.tensor(lbls)
dataset = TUDataset(graphs, diff_graphs, labels)
return dataset
class TUDataset(DGLDataset):
def __init__(self, graphs, diff_graphs, labels):
super(TUDataset, self).__init__(name="tu")
self.graphs = graphs
self.diff_graphs = diff_graphs
self.labels = labels
def process(self):
return
def __len__(self):
return len(self.graphs)
def __getitem__(self, idx):
return self.graphs[idx], self.diff_graphs[idx], self.labels[idx]