This will do it. imap :: (Shape ix, Elt a, Elt b) => (Exp ix -> Exp a -> Exp b) -> Acc (Array ix a) -> Acc (Array ix b) imap f xs = A.zipWith f (A.generate (shape xs) id) xs I'll add this and similar functions for zipWithN to the Accelerate prelude. Cheers, -Trev On Tue, 9 Feb 2016 at 06:26 Rob Stewart wrote:

In vector library there's this useful function:

imap :: (Int -> a -> b) -> Vector a -> Vector b

And in Data.Map there's this similar function:

mapWithKey :: (k -> a -> b) -> Map k a -> Map k b

I'm looking for something similar in the array and accelerate libraries, i.e.

On arrays in Data.Array.IArray:

imap :: (IArray a e, IArray a e', Ix i) => (i -> e -> e') -> a i e -> a i e'

And on Accelerate arrays:

imap :: (Shape ix, Elt a, Elt b) => (Exp ix -> Exp a -> Exp b) -> Acc (Array ix a) -> Acc (Array ix b)

Is anyone aware of such map implementations for arrays in the array and accelerate libraries, that provide your mapped function not only the element at a position, but also the index at that position?

Thanks,

-- Rob _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe