Add reverse2 to Linear.Matrix.

diff --git a/src/Linear/Matrix.hs b/src/Linear/Matrix.hs
index e4acc9ae34818f732310129279d13cb503f96c0e..c33e96691b00f9cb2c87c3332ab572a32286d10b 100644 (file)
--- a/src/Linear/Matrix.hs
+++ b/src/Linear/Matrix.hs
@@ -31,8 +31,7 @@ import Data.Vector.Fixed (
   mk2,
   mk3,
   mk4,
-  mk5
-  )
+  mk5 )
 import qualified Data.Vector.Fixed as V (
   and,
   fromList,
@@ -42,6 +41,7 @@ import qualified Data.Vector.Fixed as V (
   map,
   maximum,
   replicate,
+  reverse,
   toList,
   zipWith )
 import Data.Vector.Fixed.Cont ( Arity, arity )
@@ -875,7 +875,7 @@ map2 f (Mat rows) =
 --   Examples:
 --
 --   >>> let m = fromList [[1,2,3],[4,5,6],[7,8,9]] :: Mat3 Int
---   >>>  ifoldl2 (\i j cur _ -> cur + i + j) 0 m
+--   >>> ifoldl2 (\i j cur _ -> cur + i + j) 0 m
 --   18
 --
 ifoldl2 :: forall a b m n.
@@ -911,3 +911,23 @@ imap2 f (Mat rows) =
   Mat $ V.imap g rows
   where
     g i = V.imap (f i)
+
+
+-- | Reverse the order of elements in a matrix.
+--
+--   Examples:
+--
+--   >>> let m1 = fromList [[1,2,3]] :: Row3 Int
+--   >>> reverse2 m1
+--   ((3,2,1))
+--
+--   >>> let m1 = vec3d (1,2,3 :: Int)
+--   >>> reverse2 m1
+--   ((3),(2),(1))
+--
+--   >>> let m = fromList [[1,2,3],[4,5,6],[7,8,9]] :: Mat3 Int
+--   >>> reverse2 m
+--   ((9,8,7),(6,5,4),(3,2,1))
+--
+reverse2 :: (Arity m, Arity n) => Mat m n a -> Mat m n a
+reverse2 (Mat rows) = Mat $ V.reverse $ V.map V.reverse rows