Hello,

if "r" is a vector or a matrix, you can use UNIQUE:

UNIQUE Set unique.

UNIQUE(A) for the array A returns the same values as in A but

with no repetitions. A will also be sorted. A can be a cell

array of strings.

UNIQUE(A,'rows') for the matrix A returns the unique rows of A.

[B,I,J] = UNIQUE(...) also returns index vectors I and J such

that B = A(I) and A = B(J) (or B = A(I,:) and A = B(J,:)).

See also UNION, INTERSECT, SETDIFF, SETXOR, ISMEMBER.