3 files changed, 99 insertions, 118 deletions

diff --git a/hmatrix.cabal b/hmatrix.cabal
index a772746..7ffa01d 100644
--- a/hmatrix.cabal
+++ b/hmatrix.cabal
@@ -110,7 +110,7 @@ library
                         Numeric.LinearAlgebra,
                         Numeric.LinearAlgebra.LAPACK,
                         Numeric.LinearAlgebra.Algorithms,
-                        Numeric.LinearAlgebra.Real,
+                        Numeric.LinearAlgebra.Util,
                         Graphics.Plot,
                         Data.Packed.ST,
                         Data.Packed.Development
diff --git a/lib/Numeric/LinearAlgebra/Real.hs b/lib/Numeric/LinearAlgebra/Real.hs
deleted file mode 100644
index 8478ee7..0000000
--- a/lib/Numeric/LinearAlgebra/Real.hs
+++ /dev/null
@@ -1,117 +0,0 @@
------------------------------------------------------------------------------
-{- |
-Module      :  Numeric.LinearAlgebra.Real
-Copyright   :  (c) Alberto Ruiz 2012
-License     :  GPL
-
-Maintainer  :  Alberto Ruiz (aruiz at um dot es)
-Stability   :  provisional
-
-Additional functions for real arrays.
-
--}
------------------------------------------------------------------------------
-
-module Numeric.LinearAlgebra.Real(
-    (<>), (<\>),
-    vector,
-    linspace,
-    eye,
-    zeros, ones,
-    diagl,
-    row,
-    col,
-    (#),(&), (//), blocks,
-    rand, randn,
-    module Numeric.LinearAlgebra
-) where
-
-import Numeric.LinearAlgebra hiding ((<>), (<\>), linspace)
-import qualified Numeric.LinearAlgebra as LA
-import System.Random(randomIO)
-
-linspace :: Int -> (Double,Double) -> Vector Double
-linspace = LA.linspace
-
-
-infixl 7 <>
--- | Matrix product
-(<>) ::Mul a b c => a Double -> b Double -> c Double
-(<>) = (LA.<>)
-
-
-infixl 7 <\>
--- | Least squares solution of a linear system
-(<\>) ::LSDiv b c => Matrix Double -> b Double -> c Double
-(<\>) = (LA.<\>)
-
-
--- | Pseudorandom matrix with uniform elements between 0 and 1.
-randm :: RandDist
-     -> Int -- ^ rows
-     -> Int -- ^ columns
-     -> IO (Matrix Double)
-randm d r c = do
-    seed <- randomIO
-    return (reshape c $ randomVector seed d (r*c))
-
--- | Pseudorandom matrix with uniform elements between 0 and 1.
-rand :: Int -> Int -> IO (Matrix Double)
-rand = randm Uniform
-
--- | Pseudorandom matrix with normal elements
-randn :: Int -> Int -> IO (Matrix Double)
-randn = randm Gaussian
-
--- | Real identity matrix.
-eye :: Int -> Matrix Double
-eye = ident
-
--- | Create a real vector from a list.
-vector :: [Double] -> Vector Double
-vector = fromList
-
--- | Create a real diagonal matrix from a list.
-diagl :: [Double] -> Matrix Double
-diagl = diag . vector
-
--- | Create a matrix or zeros.
-zeros :: Int -- ^ rows
-      -> Int -- ^ columns
-      -> Matrix Double
-zeros r c = konst 0 (r,c)
-
--- | Create a matrix or ones.
-ones :: Int -- ^ rows
-     -> Int -- ^ columns
-     -> Matrix Double
-ones r c = konst 1 (r,c)
-
--- | Concatenation of real vectors.
-infixl 3 #
-(#) :: Vector Double -> Vector Double -> Vector Double
-a # b = join [a,b]
-
--- | Horizontal concatenation of real matrices.
-infixl 3 !
-(!) :: Matrix Double -> Matrix Double -> Matrix Double
-a ! b = fromBlocks [[a,b]]
-
--- | Vertical concatenation of real matrices.
-(#) :: Matrix Double -> Matrix Double -> Matrix Double
-infixl 2 #
-a # b = fromBlocks [[a],[b]]
-
-
--- | Real block matrix from a rectangular list of lists.
-blocks :: [[Matrix Double]] -> Matrix Double
-blocks = fromBlocks
-
--- | A real matrix with a single row, created from a list of elements.
-row :: [Double] -> Matrix Double
-row = asRow . vector
-
--- | A real matrix with a single column, created from a list of elements.
-col :: [Double] -> Matrix Double
-col = asColumn . vector
-
diff --git a/lib/Numeric/LinearAlgebra/Util.hs b/lib/Numeric/LinearAlgebra/Util.hs
new file mode 100644
index 0000000..416b23f
--- /dev/null
+++ b/lib/Numeric/LinearAlgebra/Util.hs
@@ -0,0 +1,98 @@
+-----------------------------------------------------------------------------
+{- |
+Module      :  Numeric.LinearAlgebra.Util
+Copyright   :  (c) Alberto Ruiz 2012
+License     :  GPL
+
+Maintainer  :  Alberto Ruiz (aruiz at um dot es)
+Stability   :  provisional
+
+-}
+-----------------------------------------------------------------------------
+
+module Numeric.LinearAlgebra.Util(
+    disp,
+    zeros, ones,
+    diagl,
+    row,
+    col,
+    (&),(!), (#),
+    rand, randn,
+    cross
+) where
+
+import Numeric.LinearAlgebra
+import System.Random(randomIO)
+
+
+disp :: Int -> Matrix Double -> IO ()
+-- ^ show a matrix with given number of digits after the decimal point
+disp n = putStrLn . dispf n
+
+-- | pseudorandom matrix with uniform elements between 0 and 1
+randm :: RandDist
+     -> Int -- ^ rows
+     -> Int -- ^ columns
+     -> IO (Matrix Double)
+randm d r c = do
+    seed <- randomIO
+    return (reshape c $ randomVector seed d (r*c))
+
+-- | pseudorandom matrix with uniform elements between 0 and 1
+rand :: Int -> Int -> IO (Matrix Double)
+rand = randm Uniform
+
+-- | pseudorandom matrix with normal elements
+randn :: Int -> Int -> IO (Matrix Double)
+randn = randm Gaussian
+
+-- | create a real diagonal matrix from a list
+diagl :: [Double] -> Matrix Double
+diagl = diag . fromList
+
+-- | a real matrix of zeros
+zeros :: Int -- ^ rows
+      -> Int -- ^ columns
+      -> Matrix Double
+zeros r c = konst 0 (r,c)
+
+-- | a real matrix of ones
+ones :: Int -- ^ rows
+     -> Int -- ^ columns
+     -> Matrix Double
+ones r c = konst 1 (r,c)
+
+-- | concatenation of real vectors
+infixl 3 &
+(&) :: Vector Double -> Vector Double -> Vector Double
+a & b = join [a,b]
+
+-- | horizontal concatenation of real matrices
+infixl 3 !
+(!) :: Matrix Double -> Matrix Double -> Matrix Double
+a ! b = fromBlocks [[a,b]]
+
+-- | vertical concatenation of real matrices
+(#) :: Matrix Double -> Matrix Double -> Matrix Double
+infixl 2 #
+a # b = fromBlocks [[a],[b]]
+
+-- | create a single row real matrix from a list
+row :: [Double] -> Matrix Double
+row = asRow . fromList
+
+-- | create a single column real matrix from a list
+col :: [Double] -> Matrix Double
+col = asColumn . fromList
+
+cross :: Vector Double -> Vector Double -> Vector Double
+-- ^ cross product of dimension 3 real vectors
+cross x y | dim x == 3 && dim y == 3 = fromList [z1,z2,z3]
+          | otherwise = error $ "cross ("++show x++") ("++show y++")"
+  where
+    [x1,x2,x3] = toList x
+    [y1,y2,y3] = toList y
+    z1 = x2*y3-x3*y2
+    z2 = x3*y1-x1*y3
+    z3 = x1*y2-x2*y1
+