01.12.2012, 15:14, "Fixie Fixie" <fixie.fi...@rocketmail.com>: > Hello haskellers > I am struggling with this package: Data.Vector.Storable.Mutable > I am creating vectors like this: MV.new 1000 :: IO (V.MVector (PrimState IO) > Int) > Now I would like access to this vectors in linear time, like I could have > done in C using pointers. > The problem is that I do not know which datastructure to keep my vectors in. > If I put them in a list, the access is very slow. Even a binary tree is very > slow compared to a C-version. > I have tried to make an array og vector of storable-mutable vectors, but have > not manged to accomplish this - even though there must be a haskell way :-)
You can use boxed vector as a first-level structure holding pointers you your storable vectors to perform O(1) indexing on first dimension. Alternatively, if your matrix is dense, store your data in a one-dimensional vector and use Repa as a thin wrapper to perform multi-dimensional indexing (see toIndex/fromIndex Data.Array.Repa.Shape). _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
