花式索引原理浅析

假设我有如下三维tensor：

matrix = torch.tensor([
    [
        [1,2,3],
        [4,5,6]
    ],
    [
        [2,3,4],
        [5,6,7]
    ]
])

索引方法为：

matrix[
    [
        [0],
        [1]
    ],
    [
        [0,1],
        [1,1]
    ],
    [
        [2,1],
        [1,2]
    ]
]

其索引过程为：