python实现将neo4j的知识图谱利用TransH嵌入方法转换成嵌入向量
时间: 2024-03-07 12:49:02 浏览: 155
以下是基于 PyTorch 实现的 TransH 算法,可以将 Neo4j 的知识图谱转换成嵌入向量:
```python
import torch
import torch.nn as nn
import torch.nn.functional as F
import numpy as np
from torch.autograd import Variable
from tqdm import tqdm
from py2neo import Graph
# 定义 TransH 模型
class TransH(nn.Module):
def __init__(self, entity_num, relation_num, dim, margin=1.0):
super(TransH, self).__init__()
self.entity_num = entity_num
self.relation_num = relation_num
self.dim = dim
self.margin = margin
# 定义实体、关系、映射矩阵
self.entity_embeddings = nn.Embedding(entity_num, dim)
self.relation_embeddings = nn.Embedding(relation_num, dim)
self.projection_matrix = nn.Embedding(relation_num, dim * dim)
def forward(self, head, relation, tail):
# 获取实体、关系、映射矩阵的向量表示
head_emb = self.entity_embeddings(head)
relation_emb = self.relation_embeddings(relation)
tail_emb = self.entity_embeddings(tail)
proj_mat = self.projection_matrix(relation)
# 将向量表示转换成矩阵表示
head_mat = head_emb.view(-1, 1, self.dim)
tail_mat = tail_emb.view(-1, 1, self.dim)
proj_mat = proj_mat.view(-1, self.dim, self.dim)
# 计算 TransH 中的映射向量
head_proj_mat = torch.matmul(head_mat, proj_mat)
tail_proj_mat = torch.matmul(tail_mat, proj_mat)
head_proj_vec = head_proj_mat.view(-1, self.dim)
tail_proj_vec = tail_proj_mat.view(-1, self.dim)
# 计算 TransH 中的距离函数
dist = torch.norm(head_proj_vec + relation_emb - tail_proj_vec, p=2, dim=1)
return dist
# 定义 TransH 中的 margin loss
def margin_loss(self, pos_dist, neg_dist):
loss = torch.sum(torch.max(pos_dist - neg_dist + self.margin, torch.zeros_like(pos_dist)))
return loss
# 定义训练函数
def train(model, train_data, optimizer, batch_size, margin):
# 将数据集分成若干个 batch
batch_num = (len(train_data) - 1) // batch_size + 1
np.random.shuffle(train_data)
total_loss = 0.0
for i in tqdm(range(batch_num)):
start_idx = i * batch_size
end_idx = min((i + 1) * batch_size, len(train_data))
batch_data = train_data[start_idx:end_idx]
head = torch.LongTensor(batch_data[:, 0])
relation = torch.LongTensor(batch_data[:, 1])
tail = torch.LongTensor(batch_data[:, 2])
neg_head = torch.LongTensor(batch_data[:, 3])
neg_tail = torch.LongTensor(batch_data[:, 4])
# 将数据转移到 GPU 上
if torch.cuda.is_available():
model.cuda()
head = head.cuda()
relation = relation.cuda()
tail = tail.cuda()
neg_head = neg_head.cuda()
neg_tail = neg_tail.cuda()
# 计算正样本和负样本的距离
pos_dist = model(head, relation, tail)
neg_dist = model(neg_head, relation, neg_tail)
# 计算 margin loss 并进行反向传播
loss = model.margin_loss(pos_dist, neg_dist)
optimizer.zero_grad()
loss.backward()
optimizer.step()
total_loss += loss.data.cpu().numpy()
return total_loss / batch_num
# 定义 TransH 算法的训练过程
def transh_train(entity_list, relation_list, triple_list, dim, lr=0.001, margin=1.0, batch_size=1024, epoch=100):
# 初始化模型和优化器
entity2id = {entity: idx for idx, entity in enumerate(entity_list)}
relation2id = {relation: idx for idx, relation in enumerate(relation_list)}
model = TransH(len(entity2id), len(relation2id), dim, margin=margin)
optimizer = torch.optim.Adam(model.parameters(), lr=lr)
# 将三元组转换成训练数据
train_data = []
for head, relation, tail in triple_list:
if head not in entity2id or tail not in entity2id or relation not in relation2id:
continue
head_id = entity2id[head]
tail_id = entity2id[tail]
relation_id = relation2id[relation]
train_data.append([head_id, relation_id, tail_id])
# 开始训练
for i in range(epoch):
loss = train(model, train_data, optimizer, batch_size, margin)
print("Epoch %d: loss=%.4f" % (i + 1, loss))
# 返回实体的嵌入向量
entity_embeddings = model.entity_embeddings.weight.data.cpu().numpy()
return entity_embeddings
# 连接 Neo4j 数据库并查询数据
graph = Graph(host="localhost", http_port=7474, user="neo4j", password="password")
result = graph.run("MATCH (n)-[r]->(m) RETURN n.name, r.name, m.name").data()
# 提取实体、关系和三元组列表
entity_list = list(set([item['n.name'] for item in result] + [item['m.name'] for item in result]))
relation_list = list(set([item['r.name'] for item in result]))
triple_list = [[item['n.name'], item['r.name'], item['m.name']] for item in result]
# 使用 TransH 算法将知识图谱转换成嵌入向量
entity_embeddings = transh_train(entity_list, relation_list, triple_list, dim=50, lr=0.01, margin=1.0, batch_size=1024, epoch=100)
# 保存实体嵌入向量
np.savetxt("entity_embeddings.txt", entity_embeddings, delimiter=",")
```
其中,`TransH` 类定义了 TransH 模型,包括实体嵌入矩阵、关系嵌入矩阵和映射矩阵,并实现了前向传播和 margin loss 函数。`train` 函数定义了模型的训练过程,包括将数据集分成若干个 batch,计算正负样本的距离和 margin loss,并进行反向传播。`transh_train` 函数定义了 TransH 算法的训练过程,包括将三元组转换成训练数据,初始化模型和优化器,并开始训练。最后将实体嵌入矩阵保存到文件中。
你需要根据自己的数据集和需求,修改代码中的参数和超参数,例如嵌入维度、学习率、margin、batch_size 和 epoch 等。
阅读全文