1 files changed, 6 insertions, 1 deletions

diff --git a/lib/GSL/Vector.hs b/lib/GSL/Vector.hs
index a772b34..a074254 100644
--- a/lib/GSL/Vector.hs
+++ b/lib/GSL/Vector.hs
@@ -18,7 +18,7 @@ module GSL.Vector (
     FunCodeV(..), vectorMapR, vectorMapC,
     FunCodeSV(..), vectorMapValR, vectorMapValC,
     FunCodeVV(..), vectorZipR, vectorZipC,
-    scale, addConstant, add, mul,
+    scale, addConstant, add, sub, mul,
 ) where
 
 import Data.Packed.Internal
@@ -84,6 +84,11 @@ add u v | isReal baseOf v = scast $ vectorZipR Add (scast u) (scast v)
                 | isComp baseOf v = scast $ vectorZipC Add (scast u) (scast v)
                 | otherwise   = fromList $ zipWith (+) (toList u) (toList v)
 
+sub :: (Num a, Field a) => Vector a -> Vector a -> Vector a
+sub u v | isReal baseOf v = scast $ vectorZipR Sub (scast u) (scast v)
+                | isComp baseOf v = scast $ vectorZipC Sub (scast u) (scast v)
+                | otherwise   = fromList $ zipWith (-) (toList u) (toList v)
+
 mul :: (Num a, Field a) => Vector a -> Vector a -> Vector a
 mul u v | isReal baseOf v = scast $ vectorZipR Mul (scast u) (scast v)
                 | isComp baseOf v = scast $ vectorZipC Mul (scast u) (scast v)