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

485 lines
15 KiB
Python

import math
from functools import partial
import dgl.function as fn
import dgl.nn.pytorch as dglnn
import torch
import torch.nn as nn
import torch.nn.functional as F
from dgl import function as fn
from dgl._ffi.base import DGLError
from dgl.base import ALL
from dgl.nn.pytorch.utils import Identity
from dgl.ops import edge_softmax
from dgl.utils import expand_as_pair
from torch.nn import init
from torch.utils.checkpoint import checkpoint
class MWEConv(nn.Module):
def __init__(
self,
in_feats,
out_feats,
activation,
bias=True,
num_channels=8,
aggr_mode="sum",
):
super(MWEConv, self).__init__()
self.num_channels = num_channels
self._in_feats = in_feats
self._out_feats = out_feats
self.weight = nn.Parameter(
torch.Tensor(in_feats, out_feats, num_channels)
)
if bias:
self.bias = nn.Parameter(torch.Tensor(out_feats, num_channels))
else:
self.bias = None
self.reset_parameters()
self.activation = activation
if aggr_mode == "concat":
self.aggr_mode = "concat"
self.final = nn.Linear(out_feats * self.num_channels, out_feats)
elif aggr_mode == "sum":
self.aggr_mode = "sum"
self.final = nn.Linear(out_feats, out_feats)
def reset_parameters(self):
stdv = 1.0 / math.sqrt(self.weight.size(1))
self.weight.data.uniform_(-stdv, stdv)
if self.bias is not None:
stdv = 1.0 / math.sqrt(self.bias.size(0))
self.bias.data.uniform_(-stdv, stdv)
def forward(self, g, node_state_prev):
node_state = node_state_prev
# if self.dropout:
# node_states = self.dropout(node_state)
g = g.local_var()
new_node_states = []
## perform weighted convolution for every channel of edge weight
for c in range(self.num_channels):
node_state_c = node_state
if self._out_feats < self._in_feats:
g.ndata["feat_" + str(c)] = torch.mm(
node_state_c, self.weight[:, :, c]
)
else:
g.ndata["feat_" + str(c)] = node_state_c
g.update_all(
fn.u_mul_e("feat_" + str(c), "feat_" + str(c), "m"),
fn.sum("m", "feat_" + str(c) + "_new"),
)
node_state_c = g.ndata.pop("feat_" + str(c) + "_new")
if self._out_feats >= self._in_feats:
node_state_c = torch.mm(node_state_c, self.weight[:, :, c])
if self.bias is not None:
node_state_c = node_state_c + self.bias[:, c]
node_state_c = self.activation(node_state_c)
new_node_states.append(node_state_c)
if self.aggr_mode == "sum":
node_states = torch.stack(new_node_states, dim=1).sum(1)
elif self.aggr_mode == "concat":
node_states = torch.cat(new_node_states, dim=1)
node_states = self.final(node_states)
return node_states
class MWE_GCN(nn.Module):
def __init__(
self,
n_input,
n_hidden,
n_output,
n_layers,
activation,
dropout,
aggr_mode="sum",
device="cpu",
):
super(MWE_GCN, self).__init__()
self.dropout = dropout
self.activation = activation
self.layers = nn.ModuleList()
self.layers.append(
MWEConv(
n_input, n_hidden, activation=activation, aggr_mode=aggr_mode
)
)
for i in range(n_layers - 1):
self.layers.append(
MWEConv(
n_hidden,
n_hidden,
activation=activation,
aggr_mode=aggr_mode,
)
)
self.pred_out = nn.Linear(n_hidden, n_output)
self.device = device
def forward(self, g, node_state=None):
node_state = torch.ones(g.num_nodes(), 1).float().to(self.device)
for layer in self.layers:
node_state = F.dropout(
node_state, p=self.dropout, training=self.training
)
node_state = layer(g, node_state)
node_state = self.activation(node_state)
out = self.pred_out(node_state)
return out
class MWE_DGCN(nn.Module):
def __init__(
self,
n_input,
n_hidden,
n_output,
n_layers,
activation,
dropout,
residual=False,
aggr_mode="sum",
device="cpu",
):
super(MWE_DGCN, self).__init__()
self.n_layers = n_layers
self.activation = activation
self.dropout = dropout
self.residual = residual
self.layers = nn.ModuleList()
self.layer_norms = nn.ModuleList()
self.layers.append(
MWEConv(
n_input, n_hidden, activation=activation, aggr_mode=aggr_mode
)
)
for i in range(n_layers - 1):
self.layers.append(
MWEConv(
n_hidden,
n_hidden,
activation=activation,
aggr_mode=aggr_mode,
)
)
for i in range(n_layers):
self.layer_norms.append(
nn.LayerNorm(n_hidden, elementwise_affine=True)
)
self.pred_out = nn.Linear(n_hidden, n_output)
self.device = device
def forward(self, g, node_state=None):
node_state = torch.ones(g.num_nodes(), 1).float().to(self.device)
node_state = self.layers[0](g, node_state)
for layer in range(1, self.n_layers):
node_state_new = self.layer_norms[layer - 1](node_state)
node_state_new = self.activation(node_state_new)
node_state_new = F.dropout(
node_state_new, p=self.dropout, training=self.training
)
if self.residual == "true":
node_state = node_state + self.layers[layer](g, node_state_new)
else:
node_state = self.layers[layer](g, node_state_new)
node_state = self.layer_norms[self.n_layers - 1](node_state)
node_state = self.activation(node_state)
node_state = F.dropout(
node_state, p=self.dropout, training=self.training
)
out = self.pred_out(node_state)
return out
class GATConv(nn.Module):
def __init__(
self,
node_feats,
edge_feats,
out_feats,
n_heads=1,
attn_drop=0.0,
edge_drop=0.0,
negative_slope=0.2,
residual=True,
activation=None,
use_attn_dst=True,
allow_zero_in_degree=True,
use_symmetric_norm=False,
):
super(GATConv, self).__init__()
self._n_heads = n_heads
self._in_src_feats, self._in_dst_feats = expand_as_pair(node_feats)
self._out_feats = out_feats
self._allow_zero_in_degree = allow_zero_in_degree
self._use_symmetric_norm = use_symmetric_norm
# feat fc
self.src_fc = nn.Linear(
self._in_src_feats, out_feats * n_heads, bias=False
)
if residual:
self.dst_fc = nn.Linear(self._in_src_feats, out_feats * n_heads)
self.bias = None
else:
self.dst_fc = None
self.bias = nn.Parameter(out_feats * n_heads)
# attn fc
self.attn_src_fc = nn.Linear(self._in_src_feats, n_heads, bias=False)
if use_attn_dst:
self.attn_dst_fc = nn.Linear(
self._in_src_feats, n_heads, bias=False
)
else:
self.attn_dst_fc = None
if edge_feats > 0:
self.attn_edge_fc = nn.Linear(edge_feats, n_heads, bias=False)
else:
self.attn_edge_fc = None
self.attn_drop = nn.Dropout(attn_drop)
self.edge_drop = edge_drop
self.leaky_relu = nn.LeakyReLU(negative_slope, inplace=True)
self.activation = activation
self.reset_parameters()
def reset_parameters(self):
gain = nn.init.calculate_gain("relu")
nn.init.xavier_normal_(self.src_fc.weight, gain=gain)
if self.dst_fc is not None:
nn.init.xavier_normal_(self.dst_fc.weight, gain=gain)
nn.init.xavier_normal_(self.attn_src_fc.weight, gain=gain)
if self.attn_dst_fc is not None:
nn.init.xavier_normal_(self.attn_dst_fc.weight, gain=gain)
if self.attn_edge_fc is not None:
nn.init.xavier_normal_(self.attn_edge_fc.weight, gain=gain)
if self.bias is not None:
nn.init.zeros_(self.bias)
def set_allow_zero_in_degree(self, set_value):
self._allow_zero_in_degree = set_value
def forward(self, graph, feat_src, feat_edge=None):
with graph.local_scope():
if not self._allow_zero_in_degree:
if (graph.in_degrees() == 0).any():
assert False
if graph.is_block:
feat_dst = feat_src[: graph.number_of_dst_nodes()]
else:
feat_dst = feat_src
if self._use_symmetric_norm:
degs = graph.srcdata["deg"]
# degs = graph.out_degrees().float().clamp(min=1)
norm = torch.pow(degs, -0.5)
shp = norm.shape + (1,) * (feat_src.dim() - 1)
norm = torch.reshape(norm, shp)
feat_src = feat_src * norm
feat_src_fc = self.src_fc(feat_src).view(
-1, self._n_heads, self._out_feats
)
feat_dst_fc = self.dst_fc(feat_dst).view(
-1, self._n_heads, self._out_feats
)
attn_src = self.attn_src_fc(feat_src).view(-1, self._n_heads, 1)
# NOTE: GAT paper uses "first concatenation then linear projection"
# to compute attention scores, while ours is "first projection then
# addition", the two approaches are mathematically equivalent:
# We decompose the weight vector a mentioned in the paper into
# [a_l || a_r], then
# a^T [Wh_i || Wh_j] = a_l Wh_i + a_r Wh_j
# Our implementation is much efficient because we do not need to
# save [Wh_i || Wh_j] on edges, which is not memory-efficient. Plus,
# addition could be optimized with DGL's built-in function u_add_v,
# which further speeds up computation and saves memory footprint.
graph.srcdata.update(
{"feat_src_fc": feat_src_fc, "attn_src": attn_src}
)
if self.attn_dst_fc is not None:
attn_dst = self.attn_dst_fc(feat_dst).view(-1, self._n_heads, 1)
graph.dstdata.update({"attn_dst": attn_dst})
graph.apply_edges(
fn.u_add_v("attn_src", "attn_dst", "attn_node")
)
else:
graph.apply_edges(fn.copy_u("attn_src", "attn_node"))
e = graph.edata["attn_node"]
if feat_edge is not None:
attn_edge = self.attn_edge_fc(feat_edge).view(
-1, self._n_heads, 1
)
graph.edata.update({"attn_edge": attn_edge})
e += graph.edata["attn_edge"]
e = self.leaky_relu(e)
if self.training and self.edge_drop > 0:
perm = torch.randperm(graph.num_edges(), device=e.device)
bound = int(graph.num_edges() * self.edge_drop)
eids = perm[bound:]
graph.edata["a"] = torch.zeros_like(e)
graph.edata["a"][eids] = self.attn_drop(
edge_softmax(graph, e[eids], eids=eids)
)
else:
graph.edata["a"] = self.attn_drop(edge_softmax(graph, e))
# message passing
graph.update_all(
fn.u_mul_e("feat_src_fc", "a", "m"), fn.sum("m", "feat_src_fc")
)
rst = graph.dstdata["feat_src_fc"]
if self._use_symmetric_norm:
degs = graph.dstdata["deg"]
# degs = graph.in_degrees().float().clamp(min=1)
norm = torch.pow(degs, 0.5)
shp = norm.shape + (1,) * (feat_dst.dim())
norm = torch.reshape(norm, shp)
rst = rst * norm
# residual
if self.dst_fc is not None:
rst += feat_dst_fc
else:
rst += self.bias
# activation
if self.activation is not None:
rst = self.activation(rst, inplace=True)
return rst
class GAT(nn.Module):
def __init__(
self,
node_feats,
edge_feats,
n_classes,
n_layers,
n_heads,
n_hidden,
edge_emb,
activation,
dropout,
input_drop,
attn_drop,
edge_drop,
use_attn_dst=True,
allow_zero_in_degree=False,
):
super().__init__()
self.n_layers = n_layers
self.n_heads = n_heads
self.n_hidden = n_hidden
self.n_classes = n_classes
self.convs = nn.ModuleList()
self.norms = nn.ModuleList()
self.node_encoder = nn.Linear(node_feats, n_hidden)
if edge_emb > 0:
self.edge_encoder = nn.ModuleList()
for i in range(n_layers):
in_hidden = n_heads * n_hidden if i > 0 else n_hidden
out_hidden = n_hidden
# bias = i == n_layers - 1
if edge_emb > 0:
self.edge_encoder.append(nn.Linear(edge_feats, edge_emb))
self.convs.append(
GATConv(
in_hidden,
edge_emb,
out_hidden,
n_heads=n_heads,
attn_drop=attn_drop,
edge_drop=edge_drop,
use_attn_dst=use_attn_dst,
allow_zero_in_degree=allow_zero_in_degree,
use_symmetric_norm=False,
)
)
self.norms.append(nn.BatchNorm1d(n_heads * out_hidden))
self.pred_linear = nn.Linear(n_heads * n_hidden, n_classes)
self.input_drop = nn.Dropout(input_drop)
self.dropout = nn.Dropout(dropout)
self.activation = activation
def forward(self, g):
if not isinstance(g, list):
subgraphs = [g] * self.n_layers
else:
subgraphs = g
h = subgraphs[0].srcdata["feat"]
h = self.node_encoder(h)
h = F.relu(h, inplace=True)
h = self.input_drop(h)
h_last = None
for i in range(self.n_layers):
if self.edge_encoder is not None:
efeat = subgraphs[i].edata["feat"]
efeat_emb = self.edge_encoder[i](efeat)
efeat_emb = F.relu(efeat_emb, inplace=True)
else:
efeat_emb = None
h = self.convs[i](subgraphs[i], h, efeat_emb).flatten(1, -1)
if h_last is not None:
h += h_last[: h.shape[0], :]
h_last = h
h = self.norms[i](h)
h = self.activation(h, inplace=True)
h = self.dropout(h)
h = self.pred_linear(h)
return h