Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints

I seem to still be missing some things. I found mt19937 in GSL.Random.Gen, but there are two evalMCs, one in Control.Monad.MC and another in Control.Monad.MC.GSL. Which? Michael --------- Registering monte-carlo-0.4.1...Installing library in /home/michael/.cabal/lib/monte-carlo-0.4.1/ghc-7.0.2Registering monte-carlo-0.4.1...[michael@sabal ~]$ ghciGHCi, version 7.0.2: http://www.haskell.org/ghc/  :? for helpLoading package ghc-prim ... linking ... done.Loading package integer-gmp ... linking ... done.Loading package base ... linking ... done.Prelude> :m + Control.Monad.MC.ClassPrelude Control.Monad.MC.Class> evalMC (sampleSubset [1..20] 5) (mt19937 0) <interactive>:1:1: Not in scope: `evalMC' <interactive>:1:34: Not in scope: `mt19937'Prelude Control.Monad.MC.Class> --- On Mon, 6/13/11, Felipe Almeida Lessa wrote: From: Felipe Almeida Lessa Subject: Re: [Haskell-cafe] Acquiring a random set of a specific size (w/o dups) from a range of Ints To: "michael rice" Cc: haskell-cafe@haskell.org Date: Monday, June 13, 2011, 9:38 PM On Mon, Jun 13, 2011 at 8:56 PM, michael rice 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.