Cheats] [Python numpy variable types and pytorch the tensor variable type of conversion

When training a neural network with pytorch, we often need to convert array variable type and tensor type pytorch in numpy today to introduce a method for mutual conversion between them.

A, numpy to tensor

First, we want to introduce the necessary packages:

import numpy as np
import torch

Then create a numpy array of type:

x = np.ones(5)
print(type(x))

 

Here creates an array of one-dimensional, five are 1, we print about this type of x is shown below:

<class 'numpy.ndarray'>

This will now be described numpy x is an array type, and then we use the following code to convert x tensor Type:

x = torch.tensor(x)
print(type(x))

The printed result is:

<class 'torch.Tensor'>

That we successfully converted!

Two, tensor to numpy

Directly on the code:

x = x.detach().numpy()
print(type(x))

Where x is just that we converted into x, print the results tensor are as follows:

<class 'numpy.ndarray'>

We have thus succeeded in converting him back ~