choice = ChooseKFromN(n,k,[unique])
Choose k distinct integers out of n. The indices come back in
randomized order if unique is absent or 0. They come back
sorted if unique is equal to 1.
4/11/94 dhb Wrote it.
2/8/98 dhb Renamed to avoid name conflict with Matlab 5 nchoosek.m
dhb Eliminate obsolete call to rand(‘uniform’).
7/24/04 awi Cosmetic.
1/29/05 dgp Cosmetic.