pytorch学习_2

##学自pytorch的官方文档

http://pytorch.org/tutorials/beginner/blitz/tensor_tutorial.html#tensors

autograd-自动微分

autograd.Variable(data,grad,creator)

data:tensor的数据

grad：该变量的导数

creator：该变量的创造者

内部原理可以参考http://www.jianshu.com/p/cbce2dd60120 的图文

import torch
from torch.autograd import Variable
x = Variable(torch.ones(2), requires_grad=True)
print(x)
y = x+1
print(y)
print(y.grad_fn)
z = y * y
out = z.mean()

print(z, out)
out.backward()
print(x.grad)