Expanding a 2D matrix to 3D

I have a 2D matrix (3000x22) of True/False values (zeros and ones). Each column contains three True values. I want to make this into a 3D matrix (3000x20x3) where the first new dimmension has the first True value, the second has the second True value, and the third has the third True value. How can I do this?

Answer 1

[Matt J]

Another way,

C=double(A); %A is the given matrix

C(logical(A))=mod(0:nnz(A)-1,3)+1;

result = cat(3, C==1, C==2, C==3)

[Camille Woicekowski]

This worked perfectly, thank you!

Answer 2

[Matt J]

Let's call your given matrix, A,

[m,n]=size(A);

[I,J]=find(A);

K=repmat((1:3).',1,n);

result=accumarray([I,J,K(:)],true,[m,n,3]);