On Sat, Sep 18, 2010 at 9:22 AM, Alexander Mikhailov <[email protected]> wrote: > we want to randomly extract a few > items from different places in the array. We may generate 11 numbers from 0 > to 5*6*7 (not including the last, 210th) > > idxs =. ?. num $ */ shp > > but then we'll need to make sure we don't have repetitions and add more > numbers until all 11 are unique. > > We can try to (re)invent a non-repeating algorithm.
Or you can just use the builtin deal dyad: idxs=: num ? */ shp NB. no repetitions Ambrus ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
