On 5/8/10, Iago Tejeda P?rez <iagotp at gmail.com> wrote:
> I was looking for a function that returns the combinations of n elements in
> groups of r.
I think you want powerset(S, r) where S is a set of n elements.
> I only found a function that returns the number of posible combinations(n,r).
For this you want binomial(n, r). There is a function in an add-on
package named combination but it simply punts to binomial:
combination(n,r):=binomial(n,r)$
This is a historical artifact and probably it should be expunged ...
Welcome to Maxima, I hope it is useful to you.
Robert Dodier