Fill array with elements located at specified subscripts in another array

1 次查看（过去 30 天）
Aaron J. Hendrickson
评论： Aaron J. Hendrickson 2017-2-17
I have a 3D array, A, of size IxJxK as well as a list of N 2D coordinates in an array I (see below). I want to fill a 2D array, B, of size KxN with the elements of A as indicated in the comments in the code below.
Asize = [128,128,64];
A = rand(Asize(1),Asize(2),Asize(3));
N = 1e+3;
[Ir,Ic] = ind2sub(Asize,randperm(prod(Asize(1:2)),N));
I = [Ir',Ic'];
B = zeros(Asize(3),N);
% B(:,n) should contain the elements A(I(n,1),I(n,2),:)
Is there a fast way to do this that does not involve loops?

请先登录，再回答此问题。

采纳的回答

Matt J
Matt J 2017-2-17
Ap=reshape( permute(A,[3,1,2]) , Asize(3),[] );
B=Ap(:, randperm(prod(Asize(1:2)),N) ).' ;

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Matrices and Arrays 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by