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

159 lines
4.6 KiB
Python
Executable File

import dgl.function as fn
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from scipy.linalg import block_diag
from model.loss import EntropyLoss
from ..model_utils import masked_softmax
from .aggregator import LSTMAggregator, MaxPoolAggregator, MeanAggregator
from .bundler import Bundler
class GraphSageLayer(nn.Module):
"""
GraphSage layer in Inductive learning paper by hamilton
Here, graphsage layer is a reduced function in DGL framework
"""
def __init__(
self,
in_feats,
out_feats,
activation,
dropout,
aggregator_type,
bn=False,
bias=True,
):
super(GraphSageLayer, self).__init__()
self.use_bn = bn
self.bundler = Bundler(
in_feats, out_feats, activation, dropout, bias=bias
)
self.dropout = nn.Dropout(p=dropout)
if aggregator_type == "maxpool":
self.aggregator = MaxPoolAggregator(
in_feats, in_feats, activation, bias
)
elif aggregator_type == "lstm":
self.aggregator = LSTMAggregator(in_feats, in_feats)
else:
self.aggregator = MeanAggregator()
def forward(self, g, h):
h = self.dropout(h)
g.ndata["h"] = h
if self.use_bn and not hasattr(self, "bn"):
device = h.device
self.bn = nn.BatchNorm1d(h.size()[1]).to(device)
g.update_all(fn.copy_u(u="h", out="m"), self.aggregator, self.bundler)
if self.use_bn:
h = self.bn(h)
h = g.ndata.pop("h")
return h
class GraphSage(nn.Module):
"""
Grahpsage network that concatenate several graphsage layer
"""
def __init__(
self,
in_feats,
n_hidden,
n_classes,
n_layers,
activation,
dropout,
aggregator_type,
):
super(GraphSage, self).__init__()
self.layers = nn.ModuleList()
# input layer
self.layers.append(
GraphSageLayer(
in_feats, n_hidden, activation, dropout, aggregator_type
)
)
# hidden layers
for _ in range(n_layers - 1):
self.layers.append(
GraphSageLayer(
n_hidden, n_hidden, activation, dropout, aggregator_type
)
)
# output layer
self.layers.append(
GraphSageLayer(n_hidden, n_classes, None, dropout, aggregator_type)
)
def forward(self, g, features):
h = features
for layer in self.layers:
h = layer(g, h)
return h
class DiffPoolBatchedGraphLayer(nn.Module):
def __init__(
self,
input_dim,
assign_dim,
output_feat_dim,
activation,
dropout,
aggregator_type,
link_pred,
):
super(DiffPoolBatchedGraphLayer, self).__init__()
self.embedding_dim = input_dim
self.assign_dim = assign_dim
self.hidden_dim = output_feat_dim
self.link_pred = link_pred
self.feat_gc = GraphSageLayer(
input_dim, output_feat_dim, activation, dropout, aggregator_type
)
self.pool_gc = GraphSageLayer(
input_dim, assign_dim, activation, dropout, aggregator_type
)
self.reg_loss = nn.ModuleList([])
self.loss_log = {}
self.reg_loss.append(EntropyLoss())
def forward(self, g, h):
feat = self.feat_gc(
g, h
) # size = (sum_N, F_out), sum_N is num of nodes in this batch
device = feat.device
assign_tensor = self.pool_gc(
g, h
) # size = (sum_N, N_a), N_a is num of nodes in pooled graph.
assign_tensor = F.softmax(assign_tensor, dim=1)
assign_tensor = torch.split(assign_tensor, g.batch_num_nodes().tolist())
assign_tensor = torch.block_diag(
*assign_tensor
) # size = (sum_N, batch_size * N_a)
h = torch.matmul(torch.t(assign_tensor), feat)
adj = g.adj_external(transpose=True, ctx=device)
adj_new = torch.sparse.mm(adj, assign_tensor)
adj_new = torch.mm(torch.t(assign_tensor), adj_new)
if self.link_pred:
current_lp_loss = torch.norm(
adj.to_dense() - torch.mm(assign_tensor, torch.t(assign_tensor))
) / np.power(g.num_nodes(), 2)
self.loss_log["LinkPredLoss"] = current_lp_loss
for loss_layer in self.reg_loss:
loss_name = str(type(loss_layer).__name__)
self.loss_log[loss_name] = loss_layer(adj, adj_new, assign_tensor)
return adj_new, h