Thanks, all. It seemed like something like this should exist in a prob/stat package, and if so, didn't want to reinvent the wheel. Shuffle [1..20], then take 5? Yes, so simple, I'm embarrassed I didn't think of it. Michael --- On Mon, 6/13/11, Felipe Almeida Lessa <felipe.lessa@gmail.com> wrote: From: Felipe Almeida Lessa <felipe.lessa@gmail.com> Subject: Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints To: "michael rice" <nowgate@yahoo.com> Cc: haskell-cafe@haskell.org Date: Monday, June 13, 2011, 9:38 PM On Mon, Jun 13, 2011 at 8:56 PM, michael rice <nowgate@yahoo.com> wrote:
Is there an (existing) way to select 5 Ints randomly (no duplicates) from a population, say 1-20 (inclusive)?
Yes, already implemented in the monte-carlo package as sampleSubset [1], sampleSubset :: MonadMC m => [a] -> Int -> m [a] Complete example code for your example: evalMC (sampleSubset [1..20] 5) (mt19937 0) Cheers! [1] http://hackage.haskell.org/packages/archive/monte-carlo/0.4.1/doc/html/Contr... -- Felipe.