{-# LANGUAGE Rank2Types #-}
-----------------------------------------------------------------------------
-- |
-- Module : Numeric.AD.Mode.Directed
-- Copyright : (c) Edward Kmett 2010
-- License : BSD3
-- Maintainer : ekmett@gmail.com
-- Stability : experimental
-- Portability : GHC only
--
-- Allows the choice of AD 'Mode' to be specified at the term level for
-- benchmarking or more complicated usage patterns.
-----------------------------------------------------------------------------
module Numeric.AD.Mode.Directed
(
-- * Gradients
grad
, grad'
-- * Jacobians
, jacobian
, jacobian'
-- * Derivatives
, diff
, diff'
-- * Exposed Types
, Direction(..)
) where
import Prelude hiding (reverse)
import Numeric.AD.Types
import Data.Traversable (Traversable)
import qualified Numeric.AD.Mode.Reverse as R
import qualified Numeric.AD.Mode.Forward as F
import qualified Numeric.AD.Mode.Tower as T
import qualified Numeric.AD as M
import Data.Ix
-- TODO: use a data types a la carte approach, so we can expose more methods here
-- rather than just the intersection of all of the functionality
data Direction
= Forward
| Reverse
| Tower
| Mixed
deriving (Show, Eq, Ord, Read, Bounded, Enum, Ix)
diff :: Num a => Direction -> (forall s. Mode s => AD s a -> AD s a) -> a -> a
diff Forward = F.diff
diff Reverse = R.diff
diff Tower = T.diff
diff Mixed = F.diff
{-# INLINE diff #-}
diff' :: Num a => Direction -> (forall s. Mode s => AD s a -> AD s a) -> a -> (a, a)
diff' Forward = F.diff'
diff' Reverse = R.diff'
diff' Tower = T.diff'
diff' Mixed = F.diff'
{-# INLINE diff' #-}
jacobian :: (Traversable f, Traversable g, Num a) => Direction -> (forall s. Mode s => f (AD s a) -> g (AD s a)) -> f a -> g (f a)
jacobian Forward = F.jacobian
jacobian Reverse = R.jacobian
jacobian Tower = F.jacobian -- error "jacobian Tower: unimplemented"
jacobian Mixed = M.jacobian
{-# INLINE jacobian #-}
jacobian' :: (Traversable f, Traversable g, Num a) => Direction -> (forall s. Mode s => f (AD s a) -> g (AD s a)) -> f a -> g (a, f a)
jacobian' Forward = F.jacobian'
jacobian' Reverse = R.jacobian'
jacobian' Tower = F.jacobian' -- error "jacobian' Tower: unimplemented"
jacobian' Mixed = M.jacobian'
{-# INLINE jacobian' #-}
grad :: (Traversable f, Num a) => Direction -> (forall s. Mode s => f (AD s a) -> AD s a) -> f a -> f a
grad Forward = F.grad
grad Reverse = R.grad
grad Tower = F.grad -- error "grad Tower: unimplemented"
grad Mixed = M.grad
{-# INLINE grad #-}
grad' :: (Traversable f, Num a) => Direction -> (forall s. Mode s => f (AD s a) -> AD s a) -> f a -> (a, f a)
grad' Forward = F.grad'
grad' Reverse = R.grad'
grad' Tower = F.grad' -- error "grad' Tower: unimplemented"
grad' Mixed = M.grad'
{-# INLINE grad' #-}