项目文件夹

文件
2020-11-27 03:20:19 +00:00

131 行
4.4 KiB
Python

import torch as th
import torch.nn as nn
class BaseRGCN(nn.Module):
def __init__(self, num_nodes, h_dim, out_dim, num_rels, num_bases,
num_hidden_layers=1, dropout=0,
use_self_loop=False, use_cuda=False):
super(BaseRGCN, self).__init__()
self.num_nodes = num_nodes
self.h_dim = h_dim
self.out_dim = out_dim
self.num_rels = num_rels
self.num_bases = None if num_bases < 0 else num_bases
self.num_hidden_layers = num_hidden_layers
self.dropout = dropout
self.use_self_loop = use_self_loop
self.use_cuda = use_cuda
# create rgcn layers
self.build_model()
def build_model(self):
self.layers = nn.ModuleList()
# i2h
i2h = self.build_input_layer()
if i2h is not None:
self.layers.append(i2h)
# h2h
for idx in range(self.num_hidden_layers):
h2h = self.build_hidden_layer(idx)
self.layers.append(h2h)
# h2o
h2o = self.build_output_layer()
if h2o is not None:
self.layers.append(h2o)
def build_input_layer(self):
return None
def build_hidden_layer(self, idx):
raise NotImplementedError
def build_output_layer(self):
return None
def forward(self, g, h, r, norm):
for layer in self.layers:
h = layer(g, h, r, norm)
return h
class RelGraphEmbedLayer(nn.Module):
r"""Embedding layer for featureless heterograph.
Parameters
----------
dev_id : int
Device to run the layer.
num_nodes : int
Number of nodes.
node_tides : tensor
Storing the node type id for each node starting from 0
num_of_ntype : int
Number of node types
input_size : list of int
A list of input feature size for each node type. If None, we then
treat certain input feature as an one-hot encoding feature.
embed_size : int
Output embed size
embed_name : str, optional
Embed name
"""
def __init__(self,
dev_id,
num_nodes,
node_tids,
num_of_ntype,
input_size,
embed_size,
sparse_emb=False,
embed_name='embed'):
super(RelGraphEmbedLayer, self).__init__()
self.dev_id = th.device(dev_id if dev_id >= 0 else 'cpu')
self.embed_size = embed_size
self.embed_name = embed_name
self.num_nodes = num_nodes
self.sparse_emb = sparse_emb
# create weight embeddings for each node for each relation
self.embeds = nn.ParameterDict()
self.num_of_ntype = num_of_ntype
self.idmap = th.empty(num_nodes).long()
for ntype in range(num_of_ntype):
if input_size[ntype] is not None:
input_emb_size = input_size[ntype].shape[1]
embed = nn.Parameter(th.Tensor(input_emb_size, self.embed_size))
nn.init.xavier_uniform_(embed)
self.embeds[str(ntype)] = embed
self.node_embeds = th.nn.Embedding(node_tids.shape[0], self.embed_size, sparse=self.sparse_emb)
nn.init.uniform_(self.node_embeds.weight, -1.0, 1.0)
def forward(self, node_ids, node_tids, type_ids, features):
"""Forward computation
Parameters
----------
node_ids : tensor
node ids to generate embedding for.
node_ids : tensor
node type ids
features : list of features
list of initial features for nodes belong to different node type.
If None, the corresponding features is an one-hot encoding feature,
else use the features directly as input feature and matmul a
projection matrix.
Returns
-------
tensor
embeddings as the input of the next layer
"""
tsd_ids = node_ids.to(self.node_embeds.weight.device)
embeds = th.empty(node_ids.shape[0], self.embed_size, device=self.dev_id)
for ntype in range(self.num_of_ntype):
if features[ntype] is not None:
loc = node_tids == ntype
embeds[loc] = features[ntype][type_ids[loc]].to(self.dev_id) @ self.embeds[str(ntype)].to(self.dev_id)
else:
loc = node_tids == ntype
embeds[loc] = self.node_embeds(tsd_ids[loc]).to(self.dev_id)
return embeds