At Fri, 15 Mar 2013 09:22:15 -0400, Amir wrote: > I have two sets T1={c1,c2,..,cn} and T2={k1,k2,...,kn}. > How can I find the sets as follow: > > (c1,k1), (c1,k2) ...(c1,kn) (c2,k1) (c2,k2) .... (c2,kn) ... (cn,kn) I think you are looking for expand.grid: expand.grid(1:3, 10:13) Var1 Var2 1 1 10 2 2 10 3 3 10 4 1 11 ... Neal