Given a Schur ring S, the function numgens outputs the number of generators of S. This is equal to the relative dimension of S over its base ring, and also to the maximal number of parts of a partition allowed as an index for the elements of S.
i1 : R = schurRing(QQ,r,6);
i2 : numgens R o2 = 6
i3 : S = schurRing(s);
i4 : numgens S o4 = infinity o4 : InfiniteNumber