torch.sort() 用法

torch.sort(input, dim=-1, descending=False, stable=False, *, out=None)
-> (Tensor, LongTensor)

延指定的维度对tensor的元素进行排序。

参数:

input(Tensor): 输入（tensor）
dim (int, optional): 指定的维度，如果没有指定，则按输入的最后一个维度排序
descending (bool, optional): 排序顺序，descending=True为递减，否则递增
stable (bool, optional): makes the sorting routine stable, which guarantees that the order of equivalent elements is preserved.

返回值:
(Tensor, LongTensor) 的元组，Tensor是排序后的tensor，LongTensor是原始tensor中元素索引组成的tensor

例:

>>> x = torch.randn(3, 4)
>>> sorted, indices = torch.sort(x)
>>> sorted
tensor([[-0.2162,  0.0608,  0.6719,  2.3332],
        [-0.5793,  0.0061,  0.6058,  0.9497],
        [-0.5071,  0.3343,  0.9553,  1.0960]])
>>> indices
tensor([[ 1,  0,  2,  3],
        [ 3,  1,  0,  2],
        [ 0,  3,  1,  2]])

>>> sorted, indices = torch.sort(x, 0)
>>> sorted
tensor([[-0.5071, -0.2162,  0.6719, -0.5793],
        [ 0.0608,  0.0061,  0.9497,  0.3343],
        [ 0.6058,  0.9553,  1.0960,  2.3332]])
>>> indices
tensor([[ 2,  0,  0,  1],
        [ 0,  1,  1,  2],
        [ 1,  2,  2,  0]])


>>> x = torch.tensor([0, 1] * 9)
>>> x.sort()
torch.return_types.sort(
    values=tensor([0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1]),
    indices=tensor([ 2, 16,  4,  6, 14,  8,  0, 10, 12,  9, 17, 15, 13, 11,  7,  5,  3,  1]))
>>> x.sort(stable=True)
torch.return_types.sort(
    values=tensor([0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1]),
    indices=tensor([ 0,  2,  4,  6,  8, 10, 12, 14, 16,  1,  3,  5,  7,  9, 11, 13, 15, 17]))

官方文档地址：https://pytorch.org/docs/stable/torch.html