MATLAB: List of IDs to matrix of indexes

Question

I have a list containing numbers like lijst = [1,1,1,2,2,3,3,3,3];

Now I want to make a matrix/cell array which counts up like:

A = [1,2,3;

4,5;

6,7,8,9];

(Essentially the number in the array is equal to the row in the matrix, and the number in the matrix is equal to the index of the array)

Is there a nice way to do this?

Answer 1

v = 1:numel(list);
[u,~,c] = unique(list);
Wanted = arrayfun(@(x) v(list == x), u,'un',0);
% or
Wanted = accumarray(c,v,[],@(x){x.'});
celldisp(Wanted)