1 files changed, 10 insertions, 3 deletions

diff --git a/lib/Numeric/LinearAlgebra/Linear.hs b/lib/Numeric/LinearAlgebra/Linear.hs
index 699985f..7e23745 100644
--- a/lib/Numeric/LinearAlgebra/Linear.hs
+++ b/lib/Numeric/LinearAlgebra/Linear.hs
@@ -23,7 +23,13 @@ import Numeric.GSL.Vector
 
 -- | A generic interface for vectors and matrices to a few element-by-element functions in Numeric.GSL.Vector.
 class (Container c e) => Linear c e where
+    -- | create a structure with a single element
+    scalar      :: e -> c e
     scale       :: e -> c e -> c e
+    -- | scale the element by element reciprocal of the object:
+    --
+    -- @scaleRecip 2 (fromList [5,i]) == 2 |> [0.4 :+ 0.0,0.0 :+ (-2.0)]@
+    scaleRecip  :: e -> c e -> c e
     addConstant :: e -> c e -> c e
     add         :: c e -> c e -> c e
     sub         :: c e -> c e -> c e
@@ -31,10 +37,8 @@ class (Container c e) => Linear c e where
     mul         :: c e -> c e -> c e
     -- | element by element division
     divide      :: c e -> c e -> c e
-    -- | scale the element by element reciprocal of the object: @scaleRecip 2 (fromList [5,i]) == 2 |> [0.4 :+ 0.0,0.0 :+ (-2.0)]@
-    scaleRecip  :: e -> c e -> c e
     equal       :: c e -> c e -> Bool
---  numequal    :: Double -> c e -> c e -> Bool
+
 
 instance Linear Vector Double where
     scale = vectorMapValR Scale
@@ -45,6 +49,7 @@ instance Linear Vector Double where
     mul = vectorZipR Mul
     divide = vectorZipR Div
     equal u v = dim u == dim v && vectorMax (vectorMapR Abs (sub u v)) == 0.0
+    scalar x = fromList [x]
 
 instance Linear Vector (Complex Double) where
     scale = vectorMapValC Scale
@@ -55,6 +60,7 @@ instance Linear Vector (Complex Double) where
     mul = vectorZipC Mul
     divide = vectorZipC Div
     equal u v = dim u == dim v && vectorMax (mapVector magnitude (sub u v)) == 0.0
+    scalar x = fromList [x]
 
 instance (Linear Vector a, Container Matrix a) => (Linear Matrix a) where
     scale x = liftMatrix (scale x)
@@ -65,3 +71,4 @@ instance (Linear Vector a, Container Matrix a) => (Linear Matrix a) where
     mul = liftMatrix2 mul
     divide = liftMatrix2 divide
     equal a b = cols a == cols b && flatten a `equal` flatten b
+    scalar x = (1><1) [x]