对数组中的维度求和

I want to do a sum over one dimension in an array. That's easy. For an array 9x100x100

我想在数组中对一个维度进行求和。这很容易。对于阵列9x100x100

sum(a,1)

However what is then left is a array with dimension 1x100x100. And now i want to get rid of the first dimension, since there is only one element left. So my solution is just:

然而,剩下的是一个尺寸为1x100x100的数组。现在我想摆脱第一个维度,因为只剩下一个元素。所以我的解决方案只是:

reshape(summed_array, 100,100)

in oder to get the 100x100 array, which i wanted. However this does not feel very clean. Is there a better way of achieving this?

在奥得河,以获得我想要的100x100阵列。然而,这感觉不是很干净。有没有更好的方法来实现这一目标?

1 个解决方案

#1

You're looking for squeeze:

你正在寻找挤压:

squeeze(A, dims)

Remove the dimensions specified by dims from array A. Elements of dims must be unique and within the range 1:ndims(A).

从阵列A中删除dims指定的尺寸.dims的元素必须是唯一的,并且在1:ndims(A)的范围内。

Example

julia> a = rand(4,3,2)
4x3x2 Array{Float64,3}:
[:, :, 1] =
 0.333543  0.83446   0.659689
 0.927134  0.885299  0.909313
 0.183557  0.263095  0.741925
 0.744499  0.509219  0.570718

[:, :, 2] =
 0.967247  0.90947   0.715283
 0.659315  0.667984  0.168867
 0.120959  0.842117  0.217277
 0.516499  0.60886   0.616639

julia> b = sum(a, 1)
1x3x2 Array{Float64,3}:
[:, :, 1] =
 2.18873  2.49207  2.88165

[:, :, 2] =
 2.26402  3.02843  1.71807

julia> c = squeeze(b, 1)
3x2 Array{Float64,2}:
 2.18873  2.26402
 2.49207  3.02843
 2.88165  1.71807