Torch - 在维度上应用函数 [英] Torch - Apply function over dimension

问题描述

我希望能够将一个为 3D 张量设计的函数应用于 4D 张量中的每个 3D 张量，即 image.translate().例如，我可以将该函数单独应用于维度 (3,50,50) 的两个图像，但如果我可以提供它们的 (2,3,50,50) 4D 连接，那就太好了.

I would like to be able to apply a function which is designed for a 3D tensor to each 3D tensor in a 4D tensor, namely image.translate(). For example, I can apply the function individually to two images of dimension (3,50,50) but it would be great if I could feed their 4D concatenation of (2,3,50,50).

这可能可以在 for 循环中完成，但我想知道是否有任何内置函数.谢谢.

This could probably be done in a for loop but I was wondering if there was any built in function for this. Thanks.

推荐答案

我还没有在 Torch 中找到这样的功能.当然，你可以自己定义一个，让你的生活更快乐一点:

I haven't managed to find such a function in Torch. You can, of course, define one yourself to make your life a little bit happier:

function apply_to_slices(tensor, dimension, func, ...)
    for i, slice in ipairs(tensor:split(1, dimension)) do
        func(slice, i, ...)
    end
    return tensor
end

示例:

function power_fill(tensor, i, power)
    power = power or 1
    tensor:fill(i ^ power)
end

A = torch.Tensor(5, 6)

apply_to_slices(A, 1, power_fill)

 1  1  1  1  1  1
 2  2  2  2  2  2
 3  3  3  3  3  3
 4  4  4  4  4  4
 5  5  5  5  5  5
[torch.DoubleTensor of size 5x6]

apply_to_slices(A, 2, power_fill, 3)

   1    8   27   64  125  216
   1    8   27   64  125  216
   1    8   27   64  125  216
   1    8   27   64  125  216
   1    8   27   64  125  216
[torch.DoubleTensor of size 5x6]

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