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

93 lines
3.2 KiB
Python

import dgl
import dgl.nn as dglnn
import sklearn.linear_model as lm
import sklearn.metrics as skm
import torch as th
import torch.functional as F
import torch.nn as nn
import tqdm
class SAGE(nn.Module):
def __init__(
self, in_feats, n_hidden, n_classes, n_layers, activation, dropout
):
super().__init__()
self.init(in_feats, n_hidden, n_classes, n_layers, activation, dropout)
def init(
self, in_feats, n_hidden, n_classes, n_layers, activation, dropout
):
self.n_layers = n_layers
self.n_hidden = n_hidden
self.n_classes = n_classes
self.layers = nn.ModuleList()
if n_layers > 1:
self.layers.append(dglnn.SAGEConv(in_feats, n_hidden, "mean"))
for i in range(1, n_layers - 1):
self.layers.append(dglnn.SAGEConv(n_hidden, n_hidden, "mean"))
self.layers.append(dglnn.SAGEConv(n_hidden, n_classes, "mean"))
else:
self.layers.append(dglnn.SAGEConv(in_feats, n_classes, "mean"))
self.dropout = nn.Dropout(dropout)
self.activation = activation
def forward(self, blocks, x):
h = x
for l, (layer, block) in enumerate(zip(self.layers, blocks)):
h = layer(
block,
h,
edge_weight=block.edata["edge_weights"]
if "edge_weights" in block.edata
else None,
)
if l != len(self.layers) - 1:
h = self.activation(h)
h = self.dropout(h)
return h
def inference(self, g, device, batch_size, use_uva, num_workers):
# The difference between this inference function and the one in the official
# example is that the intermediate results can also benefit from prefetching.
g.ndata["h"] = g.ndata["features"]
sampler = dgl.dataloading.MultiLayerFullNeighborSampler(
1, prefetch_node_feats=["h"]
)
pin_memory = g.device != device and use_uva
dataloader = dgl.dataloading.DataLoader(
g,
th.arange(g.num_nodes(), dtype=g.idtype, device=g.device),
sampler,
device=device,
batch_size=batch_size,
shuffle=False,
drop_last=False,
use_uva=use_uva,
num_workers=num_workers,
persistent_workers=(num_workers > 0),
)
self.eval()
for l, layer in enumerate(self.layers):
y = th.empty(
g.num_nodes(),
self.n_hidden if l != len(self.layers) - 1 else self.n_classes,
dtype=g.ndata["h"].dtype,
device=g.device,
pin_memory=pin_memory,
)
for input_nodes, output_nodes, blocks in tqdm.tqdm(dataloader):
x = blocks[0].srcdata["h"]
h = layer(blocks[0], x)
if l < len(self.layers) - 1:
h = self.activation(h)
h = self.dropout(h)
# by design, our output nodes are contiguous
y[output_nodes[0].item() : output_nodes[-1].item() + 1] = h.to(
y.device
)
g.ndata["h"] = y
return y