如何在 PyTorch 中对张量的元素进行排序？

在本文中，我们将了解如何在Python中对 PyTorch 张量的元素进行排序。

为了对 PyTorch 张量的元素进行排序，我们使用了 torch.sort()方法。当张量是二维的时，我们可以将元素与列或行一起排序。

Syntax: torch.sort(input, dim=- 1, descending=False)

Parameters:

• input: It is an input PyTorch tensor.
• dim: The dimension along which the tensor is sorted. It is an optional int value.
• descending: An optional boolean value used for sorting tensor elements in ascending or descending order. Default is set to False, sorting in ascending order.

Returns: It returns a named tuple of (values, indices), where values are the sorted values and indices are the indices of the elements in the original input tensor.

示例 1：

在下面的示例中，我们按升序和降序对一维张量的元素进行排序。按升序或降序对张量进行排序。我们应用torch.sort()方法对输入张量的元素进行排序。要按降序排序，请将descending=True传递给该方法。

Python3

# importing required library
import torch
  
# defining a PyTorch Tensor
tensor = torch.tensor([-12, -23, 0.0, 32,
                       1.32, 201, 5.02])
print("Tensor:\n", tensor)
  
# sorting the tensor in ascending order
print("Sorting tensor in ascending order:")
values, indices = torch.sort(tensor)
  
# printing values of sorted tensor
print("Sorted values:\n", values)
  
# printing indices of sorted value
print("Indices:\n", indices)
  
# sorting the tensor in  descending order
print("Sorting tensor in  descending order:")
values, indices = torch.sort(tensor, descending=True)
  
# printing values of sorted tensor
print("Sorted values:\n", values)
  
# printing indices of sorted value
print("Indices:\n", indices)

输出：

示例 2：

在此示例中，我们将二维张量的元素与列一起按升序和降序排序。

Python3

# importing the library
import torch
  
# define a 2D torch tensor
tensor = torch.tensor([[43,31,-92],
                       [3,-4.3,53], 
                       [-4.2,7,-6.2]])
print("Tensor:\n", tensor)
  
# sorting the tensor in  ascending order
print("Sorting tensor in \
ascending order along the column:")
values, indices = torch.sort(tensor, dim = 0)
  
# printing  values in sorted tensor
print("Sorted values:\n", values)
  
# print indices of values in sorted tensor
print("Indices:\n", indices)
  
# sorting the tensor in  descending order
print("Sorting tensor in \
descending order along the column:")
values, indices = torch.sort(tensor, dim = 0,
                             descending=True)
  
# printing  values in sorted tensor
print("Sorted values:\n", values)
  
# print indices of values in sorted tensor
print("Indices:\n", indices)

输出：

示例 3：

在这个例子中，我们按照行的升序和降序对二维张量的元素进行排序。

Python3

# importing the library
import torch
  
# define a 2D torch tensor
tensor = torch.tensor([[43, 31, -92], 
                       [3, -4.3, 53], 
                       [-4.2, 7, -6.2]])
print("Tensor:\n", tensor)
  
# sorting the tensor in  ascending order
print("Sorting tensor in \
ascending order along the row:")
values, indices = torch.sort(tensor, dim=1)
  
print("Sorted values:\n", values)
  
# print indices of values in sorted tensor
print("Indices:\n", indices)
  
# sorting the tensor in  descending order
print("Sorting tensor in \
descending order along the row:")
values, indices = torch.sort(tensor,
                             dim=1,
                             descending=True)
  
# printing  values in sorted tensor
print("Sorted values:\n", values)
  
# printing indices of values in sorted tensor
print("Indices:\n", indices)

输出：