用PyTorch类实现Logistic regression

1.PyTorch基础实现代码

import torch
from torch.autograd import Variable
 
torch.manual_seed(2)
x_data = Variable(torch.Tensor([[1.0], [2.0], [3.0], [4.0]]))
y_data = Variable(torch.Tensor([[0.0], [0.0], [1.0], [1.0]]))
 
# 初始化
w = Variable(torch.Tensor([-1]), requires_grad=True)
b = Variable(torch.Tensor([0]), requires_grad=True)
 
epochs = 100
costs = []
lr = 0.1
 
print('before training,predict of x = 1.5 is :')
print