find 4d matrix positions

Question

john_arle 2019-11-5

编辑： Stephen23 2019-11-5

Hello!

i want to searcha 4d matrix to find all indeces relative to non yero elements.

<i would like to store those indeces in n times 4 matrix,

where n is the number of points found.

I tried with ind2sub but it was useless.

Answer 1

Stephen23 2019-11-5

编辑：Stephen23 2019-11-5

"I tried with ind2sub but it was useless."

It worked for me. First lets define some fake data:

>> A = zeros(5,4,3,2);
>> A(5,3,2,1) = 1;
>> A(3,1,1,2) = 1;

then get the indices of non-zero array elements:

>> [R,C,P,Q] = ind2sub(size(A),find(A));
>> M = [R,C,P,Q]
M =
     5     3     2     1
     3     1     1     2