MATLAB: Transforming a 2-dim array integers to 3-dim array of logical which are true for the corresponding number – without using a loop

matrix

Hello,
I would like to take an 2-dim array like
IND=[4 3 2; 
     1 2 3];
and create a 3-dim of logicals like
GOAL(:,:,1)=[0 0 0 1;
             1 0 0 0]
GOAL(:,:,2)=[0 0 1 0;
             0 1 0 0]
GOAL(:,:,3)=[0 1 0 0;
             0 0 1 0]
So the first second dimension is newly created, it is as long as the highest number in IND and is zero(false), except for the indice, that is 1(true)
I really need it to be fast, so a for loop will not do.
Many thanks Marcus

Best Answer

IND=[4 3 2; 
     1 2 3];
[I,~,K] = ndgrid(1:size(IND,1),1,1:size(IND,2));
J = IND;
GOAL = accumarray([I(:),J(:),K(:)],1);
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