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

209 lines
6.4 KiB
Python

import dgl.function as fn
import numpy as np
import torch as th
import torch.nn as nn
class CAREConv(nn.Module):
"""One layer of CARE-GNN."""
def __init__(
self,
in_dim,
out_dim,
num_classes,
edges,
activation=None,
step_size=0.02,
):
super(CAREConv, self).__init__()
self.activation = activation
self.step_size = step_size
self.in_dim = in_dim
self.out_dim = out_dim
self.num_classes = num_classes
self.edges = edges
self.dist = {}
self.linear = nn.Linear(self.in_dim, self.out_dim)
self.MLP = nn.Linear(self.in_dim, self.num_classes)
self.p = {}
self.last_avg_dist = {}
self.f = {}
self.cvg = {}
for etype in edges:
self.p[etype] = 0.5
self.last_avg_dist[etype] = 0
self.f[etype] = []
self.cvg[etype] = False
def _calc_distance(self, edges):
# formula 2
d = th.norm(
th.tanh(self.MLP(edges.src["h"]))
- th.tanh(self.MLP(edges.dst["h"])),
1,
1,
)
return {"d": d}
def _top_p_sampling(self, g, p):
# this implementation is low efficient
# optimization requires dgl.sampling.select_top_p requested in issue #3100
dist = g.edata["d"]
neigh_list = []
for node in g.nodes():
edges = g.in_edges(node, form="eid")
num_neigh = th.ceil(g.in_degrees(node) * p).int().item()
neigh_dist = dist[edges]
if neigh_dist.shape[0] > num_neigh:
neigh_index = np.argpartition(
neigh_dist.cpu().detach(), num_neigh
)[:num_neigh]
else:
neigh_index = np.arange(num_neigh)
neigh_list.append(edges[neigh_index])
return th.cat(neigh_list)
def forward(self, g, feat):
with g.local_scope():
g.ndata["h"] = feat
hr = {}
for i, etype in enumerate(g.canonical_etypes):
g.apply_edges(self._calc_distance, etype=etype)
self.dist[etype] = g.edges[etype].data["d"]
sampled_edges = self._top_p_sampling(g[etype], self.p[etype])
# formula 8
g.send_and_recv(
sampled_edges,
fn.copy_u("h", "m"),
fn.mean("m", "h_%s" % etype[1]),
etype=etype,
)
hr[etype] = g.ndata["h_%s" % etype[1]]
if self.activation is not None:
hr[etype] = self.activation(hr[etype])
# formula 9 using mean as inter-relation aggregator
p_tensor = (
th.Tensor(list(self.p.values())).view(-1, 1, 1).to(g.device)
)
h_homo = th.sum(th.stack(list(hr.values())) * p_tensor, dim=0)
h_homo += feat
if self.activation is not None:
h_homo = self.activation(h_homo)
return self.linear(h_homo)
class CAREGNN(nn.Module):
def __init__(
self,
in_dim,
num_classes,
hid_dim=64,
edges=None,
num_layers=2,
activation=None,
step_size=0.02,
):
super(CAREGNN, self).__init__()
self.in_dim = in_dim
self.hid_dim = hid_dim
self.num_classes = num_classes
self.edges = edges
self.activation = activation
self.step_size = step_size
self.num_layers = num_layers
self.layers = nn.ModuleList()
if self.num_layers == 1:
# Single layer
self.layers.append(
CAREConv(
self.in_dim,
self.num_classes,
self.num_classes,
self.edges,
activation=self.activation,
step_size=self.step_size,
)
)
else:
# Input layer
self.layers.append(
CAREConv(
self.in_dim,
self.hid_dim,
self.num_classes,
self.edges,
activation=self.activation,
step_size=self.step_size,
)
)
# Hidden layers with n - 2 layers
for i in range(self.num_layers - 2):
self.layers.append(
CAREConv(
self.hid_dim,
self.hid_dim,
self.num_classes,
self.edges,
activation=self.activation,
step_size=self.step_size,
)
)
# Output layer
self.layers.append(
CAREConv(
self.hid_dim,
self.num_classes,
self.num_classes,
self.edges,
activation=self.activation,
step_size=self.step_size,
)
)
def forward(self, graph, feat):
# For full graph training, directly use the graph
# formula 4
sim = th.tanh(self.layers[0].MLP(feat))
# Forward of n layers of CARE-GNN
for layer in self.layers:
feat = layer(graph, feat)
return feat, sim
def RLModule(self, graph, epoch, idx):
for layer in self.layers:
for etype in self.edges:
if not layer.cvg[etype]:
# formula 5
eid = graph.in_edges(idx, form="eid", etype=etype)
avg_dist = th.mean(layer.dist[etype][eid])
# formula 6
if layer.last_avg_dist[etype] < avg_dist:
if layer.p[etype] - self.step_size > 0:
layer.p[etype] -= self.step_size
layer.f[etype].append(-1)
else:
if layer.p[etype] + self.step_size <= 1:
layer.p[etype] += self.step_size
layer.f[etype].append(+1)
layer.last_avg_dist[etype] = avg_dist
# formula 7
if epoch >= 9 and abs(sum(layer.f[etype][-10:])) <= 2:
layer.cvg[etype] = True