Group a Array Elements

X=[1 2 3 3 3 1]

index 1 -> 1 index 2 -> 2 index 3 -> 3 index 4 -> 3 index 5 -> 5 index 6 -> 1

y=[{1,6},{2},{3,4,5}]

How create matrix y?

Answer 1

[KSSV]

X=[1 2 3 3 3 1] ;

[c,ia,ib] = unique(X) ;
iwant = cell(length(c),1) ;
for i = 1:length(c)
    iwant{i} = find(ib==i) ;
    iwant{i}
end