GNNRecom/gnnrec/hge/hgconv/model.py

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2021-11-16 07:04:52 +00:00
import dgl.function as fn
import torch
import torch.nn as nn
import torch.nn.functional as F
from dgl.dataloading import MultiLayerFullNeighborSampler, NodeDataLoader
from dgl.ops import edge_softmax
from dgl.utils import expand_as_pair
from tqdm import tqdm
class MicroConv(nn.Module):
def __init__(
self, out_dim, num_heads, fc_src, fc_dst, attn_src,
feat_drop=0.0, negative_slope=0.2, activation=None):
"""微观层次卷积
针对一种关系边类型R=<stype, etype, dtype>聚集关系R下的邻居信息得到关系R关于dtype类型顶点的表示
特征转换矩阵和注意力向量是与顶点类型相关的除此之外与GAT完全相同
:param out_dim: int 输出特征维数
:param num_heads: int 注意力头数K
:param fc_src: nn.Linear(d_in, K*d_out) 源顶点特征转换模块
:param fc_dst: nn.Linear(d_in, K*d_out) 目标顶点特征转换模块
:param attn_src: nn.Parameter(K, 2d_out) 源顶点类型对应的注意力向量
:param feat_drop: float, optional 输入特征Dropout概率默认为0
:param negative_slope: float, optional LeakyReLU负斜率默认为0.2
:param activation: callable, optional 用于输出特征的激活函数默认为None
"""
super().__init__()
self.out_dim = out_dim
self.num_heads = num_heads
self.fc_src = fc_src
self.fc_dst = fc_dst
self.attn_src = attn_src
self.feat_drop = nn.Dropout(feat_drop)
self.leaky_relu = nn.LeakyReLU(negative_slope)
self.activation = activation
def forward(self, g, feat):
"""
:param g: DGLGraph 二分图只包含一种关系
:param feat: tensor(N_src, d_in) or (tensor(N_src, d_in), tensor(N_dst, d_in)) 输入特征
:return: tensor(N_dst, K*d_out) 该关系关于目标顶点的表示
"""
with g.local_scope():
feat_src, feat_dst = expand_as_pair(feat, g)
feat_src = self.fc_src(self.feat_drop(feat_src)).view(-1, self.num_heads, self.out_dim)
feat_dst = self.fc_dst(self.feat_drop(feat_dst)).view(-1, self.num_heads, self.out_dim)
# a^T (z_u || z_v) = (a_l^T || a_r^T) (z_u || z_v) = a_l^T z_u + a_r^T z_v = el + er
el = (feat_src * self.attn_src[:, :self.out_dim]).sum(dim=-1, keepdim=True) # (N_src, K, 1)
er = (feat_dst * self.attn_src[:, self.out_dim:]).sum(dim=-1, keepdim=True) # (N_dst, K, 1)
g.srcdata.update({'ft': feat_src, 'el': el})
g.dstdata['er'] = er
g.apply_edges(fn.u_add_v('el', 'er', 'e'))
e = self.leaky_relu(g.edata.pop('e'))
g.edata['a'] = edge_softmax(g, e) # (E, K, 1)
# 消息传递
g.update_all(fn.u_mul_e('ft', 'a', 'm'), fn.sum('m', 'ft'))
ret = g.dstdata['ft'].view(-1, self.num_heads * self.out_dim)
if self.activation:
ret = self.activation(ret)
return ret
class MacroConv(nn.Module):
def __init__(self, out_dim, num_heads, fc_node, fc_rel, attn, dropout=0.0, negative_slope=0.2):
"""宏观层次卷积
针对所有关系边类型将每种类型的顶点关联的所有关系关于该类型顶点的表示组合起来
:param out_dim: int 输出特征维数
:param num_heads: int 注意力头数K
:param fc_node: Dict[str, nn.Linear(d_in, K*d_out)] 顶点类型到顶点特征转换模块的映射
:param fc_rel: Dict[str, nn.Linear(K*d_out, K*d_out)] 关系到关系表示转换模块的映射
:param attn: nn.Parameter(K, 2d_out)
:param dropout: float, optional Dropout概率默认为0
:param negative_slope: float, optional LeakyReLU负斜率默认为0.2
"""
super().__init__()
self.out_dim = out_dim
self.num_heads = num_heads
self.fc_node = fc_node
self.fc_rel = fc_rel
self.attn = attn
self.dropout = nn.Dropout(dropout)
self.leaky_relu = nn.LeakyReLU(negative_slope)
def forward(self, node_feats, rel_feats):
"""
:param node_feats: Dict[str, tensor(N_i, d_in) 顶点类型到输入顶点特征的映射
:param rel_feats: Dict[(str, str, str), tensor(N_i, K*d_out)]
关系(stype, etype, dtype)到关系关于其终点类型的表示的映射
:return: Dict[str, tensor(N_i, K*d_out)] 顶点类型到最终顶点嵌入的映射
"""
node_feats = {
ntype: self.fc_node[ntype](feat).view(-1, self.num_heads, self.out_dim)
for ntype, feat in node_feats.items()
}
rel_feats = {
r: self.fc_rel[r[1]](feat).view(-1, self.num_heads, self.out_dim)
for r, feat in rel_feats.items()
}
out_feats = {}
for ntype, node_feat in node_feats.items():
rel_node_feats = [feat for rel, feat in rel_feats.items() if rel[2] == ntype]
if not rel_node_feats:
continue
elif len(rel_node_feats) == 1:
out_feats[ntype] = rel_node_feats[0].view(-1, self.num_heads * self.out_dim)
else:
rel_node_feats = torch.stack(rel_node_feats, dim=0) # (R, N_i, K, d_out)
cat_feats = torch.cat(
(node_feat.repeat(rel_node_feats.shape[0], 1, 1, 1), rel_node_feats), dim=-1
) # (R, N_i, K, 2d_out)
attn_scores = self.leaky_relu((self.attn * cat_feats).sum(dim=-1, keepdim=True))
attn_scores = F.softmax(attn_scores, dim=0) # (R, N_i, K, 1)
out_feat = (attn_scores * rel_node_feats).sum(dim=0) # (N_i, K, d_out)
out_feats[ntype] = self.dropout(out_feat.reshape(-1, self.num_heads * self.out_dim))
return out_feats
class HGConvLayer(nn.Module):
def __init__(self, in_dim, out_dim, num_heads, ntypes, etypes, dropout=0.0, residual=True):
"""HGConv层
:param in_dim: int 输入特征维数
:param out_dim: int 输出特征维数
:param num_heads: int 注意力头数K
:param ntypes: List[str] 顶点类型列表
:param etypes: List[(str, str, str)] 规范边类型列表
:param dropout: float, optional Dropout概率默认为0
:param residual: bool, optional 是否使用残差连接默认True
"""
super().__init__()
# 微观层次卷积的参数
micro_fc = {ntype: nn.Linear(in_dim, num_heads * out_dim, bias=False) for ntype in ntypes}
micro_attn = {
ntype: nn.Parameter(torch.FloatTensor(size=(num_heads, 2 * out_dim)))
for ntype in ntypes
}
# 宏观层次卷积的参数
macro_fc_node = nn.ModuleDict({
ntype: nn.Linear(in_dim, num_heads * out_dim, bias=False) for ntype in ntypes
})
macro_fc_rel = nn.ModuleDict({
r[1]: nn.Linear(num_heads * out_dim, num_heads * out_dim, bias=False)
for r in etypes
})
macro_attn = nn.Parameter(torch.FloatTensor(size=(num_heads, 2 * out_dim)))
self.micro_conv = nn.ModuleDict({
etype: MicroConv(
out_dim, num_heads, micro_fc[stype],
micro_fc[dtype], micro_attn[stype], dropout, activation=F.relu
) for stype, etype, dtype in etypes
})
self.macro_conv = MacroConv(
out_dim, num_heads, macro_fc_node, macro_fc_rel, macro_attn, dropout
)
self.residual = residual
if residual:
self.res_fc = nn.ModuleDict({
ntype: nn.Linear(in_dim, num_heads * out_dim) for ntype in ntypes
})
self.res_weight = nn.ParameterDict({
ntype: nn.Parameter(torch.rand(1)) for ntype in ntypes
})
self.reset_parameters(micro_fc, micro_attn, macro_fc_node, macro_fc_rel, macro_attn)
def reset_parameters(self, micro_fc, micro_attn, macro_fc_node, macro_fc_rel, macro_attn):
gain = nn.init.calculate_gain('relu')
for ntype in micro_fc:
nn.init.xavier_normal_(micro_fc[ntype].weight, gain=gain)
nn.init.xavier_normal_(micro_attn[ntype], gain=gain)
nn.init.xavier_normal_(macro_fc_node[ntype].weight, gain=gain)
if self.residual:
nn.init.xavier_normal_(self.res_fc[ntype].weight, gain=gain)
for etype in macro_fc_rel:
nn.init.xavier_normal_(macro_fc_rel[etype].weight, gain=gain)
nn.init.xavier_normal_(macro_attn, gain=gain)
def forward(self, g, feats):
"""
:param g: DGLGraph 异构图
:param feats: Dict[str, tensor(N_i, d_in)] 顶点类型到输入顶点特征的映射
:return: Dict[str, tensor(N_i, K*d_out)] 顶点类型到最终顶点嵌入的映射
"""
if g.is_block:
feats_dst = {ntype: feats[ntype][:g.num_dst_nodes(ntype)] for ntype in feats}
else:
feats_dst = feats
rel_feats = {
(stype, etype, dtype): self.micro_conv[etype](
g[stype, etype, dtype], (feats[stype], feats_dst[dtype])
)
for stype, etype, dtype in g.canonical_etypes
if g.num_edges((stype, etype, dtype)) > 0
} # {rel: tensor(N_i, K*d_out)}
out_feats = self.macro_conv(feats_dst, rel_feats) # {ntype: tensor(N_i, K*d_out)}
if self.residual:
for ntype in out_feats:
alpha = torch.sigmoid(self.res_weight[ntype])
inherit_feat = self.res_fc[ntype](feats_dst[ntype])
out_feats[ntype] = alpha * out_feats[ntype] + (1 - alpha) * inherit_feat
return out_feats
class HGConv(nn.Module):
def __init__(
self, in_dims, hidden_dim, out_dim, num_heads, ntypes, etypes, predict_ntype,
num_layers, dropout=0.0, residual=True):
"""HGConv模型
:param in_dims: Dict[str, int] 顶点类型到输入特征维数的映射
:param hidden_dim: int 隐含特征维数
:param out_dim: int 输出特征维数
:param num_heads: int 注意力头数K
:param ntypes: List[str] 顶点类型列表
:param etypes: List[(str, str, str)] 规范边类型列表
:param predict_ntype: str 待预测顶点类型
:param num_layers: int 层数
:param dropout: float, optional Dropout概率默认为0
:param residual: bool, optional 是否使用残差连接默认True
"""
super().__init__()
self.d = num_heads * hidden_dim
self.predict_ntype = predict_ntype
# 对齐输入特征维数
self.fc_in = nn.ModuleDict({
ntype: nn.Linear(in_dim, num_heads * hidden_dim) for ntype, in_dim in in_dims.items()
})
self.layers = nn.ModuleList([
HGConvLayer(
num_heads * hidden_dim, hidden_dim, num_heads, ntypes, etypes, dropout, residual
) for _ in range(num_layers)
])
self.classifier = nn.Linear(num_heads * hidden_dim, out_dim)
def forward(self, blocks, feats):
"""
:param blocks: List[DGLBlock]
:param feats: Dict[str, tensor(N_i, d_in_i)] 顶点类型到输入顶点特征的映射
:return: tensor(N_i, d_out) 待预测顶点的最终嵌入
"""
feats = {ntype: self.fc_in[ntype](feat) for ntype, feat in feats.items()}
for i in range(len(self.layers)):
feats = self.layers[i](blocks[i], feats) # {ntype: tensor(N_i, K*d_hid)}
return self.classifier(feats[self.predict_ntype])
@torch.no_grad()
def inference(self, g, feats, device, batch_size):
"""离线推断所有顶点的最终嵌入(不使用邻居采样)
:param g: DGLGraph 异构图
:param feats: Dict[str, tensor(N_i, d_in_i)] 顶点类型到输入顶点特征的映射
:param device: torch.device
:param batch_size: int 批大小
:return: tensor(N_i, d_out) 待预测顶点的最终嵌入
"""
g.ndata['emb'] = {ntype: self.fc_in[ntype](feat) for ntype, feat in feats.items()}
for layer in self.layers:
embeds = {
ntype: torch.zeros(g.num_nodes(ntype), self.d, device=device)
for ntype in g.ntypes
}
sampler = MultiLayerFullNeighborSampler(1)
loader = NodeDataLoader(
g, {ntype: g.nodes(ntype) for ntype in g.ntypes}, sampler, device=device,
batch_size=batch_size, shuffle=True
)
for input_nodes, output_nodes, blocks in tqdm(loader):
block = blocks[0]
h = layer(block, block.srcdata['emb'])
for ntype in h:
embeds[ntype][output_nodes[ntype]] = h[ntype]
g.ndata['emb'] = embeds
return self.classifier(g.nodes[self.predict_ntype].data['emb'])
class HGConvFull(HGConv):
def forward(self, g, feats):
return super().forward([g] * len(self.layers), feats)