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diff --git a/lib/GSL/Matrix.hs b/lib/GSL/Matrix.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module      :  GSL.Matrix
+-- Copyright   :  (c) Alberto Ruiz 2007
+-- License     :  GPL-style
+--
+-- Maintainer  :  Alberto Ruiz <aruiz@um.es>
+-- Stability   :  provisional
+-- Portability :  portable (uses FFI)
+--
+-- A few linear algebra computations based on the GSL (<http://www.gnu.org/software/gsl>).
+--
+-----------------------------------------------------------------------------
+
+module GSL.Matrix(
+    eigSg, eigHg,
+    svdg,
+    qr,
+    chol,
+    luSolveR, luSolveC,
+    luR, luC,
+    fromFile
+) where
+
+import Data.Packed.Internal
+import Data.Packed.Matrix(fromLists,ident,takeDiag)
+import GSL.Vector
+import Foreign
+import Foreign.C.Types
+import Complex
+import Foreign.C.String
+
+{- | eigendecomposition of a real symmetric matrix using /gsl_eigen_symmv/.
+
+> > let (l,v) = eigS $ 'fromLists' [[1,2],[2,1]]
+> > l
+> 3.000 -1.000
+>
+> > v
+> 0.707 -0.707
+> 0.707  0.707
+>
+> > v <> diag l <> trans v
+> 1.000 2.000
+> 2.000 1.000
+
+-}
+eigSg :: Matrix Double -> (Vector Double, Matrix Double)
+eigSg (m@M {rows = r})
+    | r == 1 = (fromList [cdat m `at` 0], singleton 1)
+    | otherwise = unsafePerformIO $ do
+        l <- createVector r
+        v <- createMatrix RowMajor r r
+        c_eigS // mat cdat m // vec l // mat dat v // check "eigSg" [cdat m]
+        return (l,v)
+foreign import ccall "gsl-aux.h eigensystemR" c_eigS :: TMVM
+
+------------------------------------------------------------------
+
+
+
+{- | eigendecomposition of a complex hermitian matrix using /gsl_eigen_hermv/
+
+> > let (l,v) = eigH $ 'fromLists' [[1,2+i],[2-i,3]]
+>
+> > l
+> 4.449 -0.449
+>
+> > v
+>         -0.544          0.839
+> (-0.751,0.375) (-0.487,0.243)
+>
+> > v <> diag l <> (conjTrans) v
+>          1.000 (2.000,1.000)
+> (2.000,-1.000)         3.000
+
+-}
+eigHg :: Matrix (Complex Double)-> (Vector Double, Matrix (Complex Double))
+eigHg (m@M {rows = r})
+    | r == 1 = (fromList [realPart $ cdat m `at` 0], singleton 1)
+    | otherwise = unsafePerformIO $ do
+        l <- createVector r
+        v <- createMatrix RowMajor r r
+        c_eigH // mat cdat m // vec l // mat dat v // check "eigHg" [cdat m]
+        return (l,v)
+foreign import ccall "gsl-aux.h eigensystemC" c_eigH :: TCMVCM
+
+
+{- | Singular value decomposition of a real matrix, using /gsl_linalg_SV_decomp_mod/:
+
+@\> let (u,s,v) = svdg $ 'fromLists' [[1,2,3],[-4,1,7]]
+\
+\> u
+0.310 -0.951
+0.951  0.310
+\
+\> s
+8.497 2.792
+\
+\> v
+-0.411 -0.785
+ 0.185 -0.570
+ 0.893 -0.243
+\
+\> u \<\> 'diag' s \<\> 'trans' v
+ 1. 2. 3.
+-4. 1. 7.@
+
+-}
+svdg :: Matrix Double -> (Matrix Double, Vector Double, Matrix Double)
+svdg x@M {rows = r, cols = c} = if r>=c
+    then svd' x
+    else (v, s, u) where (u,s,v) = svd' (trans x)
+
+svd' x@M {rows = r, cols = c} = unsafePerformIO $ do
+    u <- createMatrix RowMajor r c
+    s <- createVector c
+    v <- createMatrix RowMajor c c
+    c_svd // mat cdat x // mat dat u // vec s // mat dat v // check "svdg" [cdat x]
+    return (u,s,v)
+foreign import ccall "gsl-aux.h svd" c_svd :: TMMVM
+
+{- | QR decomposition of a real matrix using /gsl_linalg_QR_decomp/ and /gsl_linalg_QR_unpack/.
+
+@\> let (q,r) = qr $ 'fromLists' [[1,3,5,7],[2,0,-2,4]]
+\
+\> q
+-0.447 -0.894
+-0.894  0.447
+\
+\> r
+-2.236 -1.342 -0.447 -6.708
+    0. -2.683 -5.367 -4.472
+\
+\> q \<\> r
+1.000 3.000  5.000 7.000
+2.000    0. -2.000 4.000@
+
+-}
+qr :: Matrix Double -> (Matrix Double, Matrix Double)
+qr x@M {rows = r, cols = c} = unsafePerformIO $ do
+    q <- createMatrix RowMajor r r
+    rot <- createMatrix RowMajor r c
+    c_qr // mat cdat x // mat dat q // mat dat rot // check "qr" [cdat x]
+    return (q,rot)
+foreign import ccall "gsl-aux.h QR" c_qr :: TMMM
+
+{- | Cholesky decomposition of a symmetric positive definite real matrix using /gsl_linalg_cholesky_decomp/.
+
+@\> let c = chol $ 'fromLists' [[5,4],[4,5]]
+\
+\> c
+2.236    0.
+1.789 1.342
+\
+\> c \<\> 'trans' c
+5.000 4.000
+4.000 5.000@
+
+-}
+chol :: Matrix Double -> Matrix Double
+--chol x@(M r _ p) = createM [p] "chol" r r $ m c_chol x
+chol x@M {rows = r} = unsafePerformIO $ do
+    res <- createMatrix RowMajor r r
+    c_chol // mat cdat x // mat dat res // check "chol" [cdat x]
+    return res
+foreign import ccall "gsl-aux.h chol" c_chol :: TMM
+
+--------------------------------------------------------
+
+{- -| efficient multiplication by the inverse of a matrix (for real matrices)
+-}
+luSolveR :: Matrix Double -> Matrix Double -> Matrix Double
+luSolveR  a@(M {rows = n1, cols = n2}) b@(M {rows = r, cols = c})
+    | n1==n2 && n1==r = unsafePerformIO $ do
+        s <- createMatrix RowMajor r c
+        c_luSolveR // mat cdat a // mat cdat b // mat dat s // check "luSolveR" [cdat a, cdat b]
+        return s
+    | otherwise = error "luSolveR of nonsquare matrix"
+
+foreign import ccall "gsl-aux.h luSolveR" c_luSolveR ::  TMMM
+
+{- -| efficient multiplication by the inverse of a matrix (for complex matrices). 
+-}
+luSolveC :: Matrix (Complex Double) -> Matrix (Complex Double) -> Matrix (Complex Double)
+luSolveC  a@(M {rows = n1, cols = n2}) b@(M {rows = r, cols = c})
+    | n1==n2 && n1==r = unsafePerformIO $ do
+        s <- createMatrix RowMajor r c
+        c_luSolveC // mat cdat a // mat cdat b // mat dat s // check "luSolveC" [cdat a, cdat b]
+        return s
+    | otherwise = error "luSolveC of nonsquare matrix"
+
+foreign import ccall "gsl-aux.h luSolveC" c_luSolveC ::  TCMCMCM
+
+{- | lu decomposition of real matrix (packed as a vector including l, u, the permutation and sign)
+-}
+luRaux  :: Matrix Double -> Vector Double
+luRaux x@M {rows = r, cols = c} = unsafePerformIO $ do
+    res <- createVector (r*r+r+1)
+    c_luRaux // mat cdat x // vec res // check "luRaux" [cdat x]
+    return res
+foreign import ccall "gsl-aux.h luRaux" c_luRaux :: TMV
+
+{- | lu decomposition of complex matrix (packed as a vector including l, u, the permutation and sign)
+-}
+luCaux  :: Matrix (Complex Double) -> Vector (Complex Double)
+luCaux x@M {rows = r, cols = c} = unsafePerformIO $ do
+    res <- createVector (r*r+r+1)
+    c_luCaux // mat cdat x // vec res // check "luCaux" [cdat x]
+    return res
+foreign import ccall "gsl-aux.h luCaux" c_luCaux :: TCMCV
+
+{- | The LU decomposition of a square matrix. Is based on /gsl_linalg_LU_decomp/ and  /gsl_linalg_complex_LU_decomp/ as described in <http://www.gnu.org/software/gsl/manual/gsl-ref_13.html#SEC223>.
+
+@\> let m = 'fromLists' [[1,2,-3],[2+3*i,-7,0],[1,-i,2*i]]
+\> let (l,u,p,s) = luR m@
+
+L is the lower triangular:
+
+@\> l
+          1.            0.  0.
+0.154-0.231i            1.  0.
+0.154-0.231i  0.624-0.522i  1.@
+
+U is the upper triangular:
+
+@\> u
+2.+3.i           -7.            0.
+    0.  3.077-1.615i           -3.
+    0.            0.  1.873+0.433i@
+
+p is a permutation:
+
+@\> p
+[1,0,2]@
+
+L \* U obtains a permuted version of the original matrix:
+
+@\> 'extractRows' p m
+  2.+3.i   -7.   0.
+      1.    2.  -3.
+      1.  -1.i  2.i
+\ 
+\> l \<\> u
+ 2.+3.i   -7.   0.
+     1.    2.  -3.
+     1.  -1.i  2.i@
+
+s is the sign of the permutation, required to obtain sign of the determinant:
+
+@\> s * product ('toList' $ 'takeDiag' u)
+(-18.0) :+ (-16.000000000000004)
+\> 'LinearAlgebra.Algorithms.det' m
+(-18.0) :+ (-16.000000000000004)@
+
+ -}
+luR :: Matrix Double -> (Matrix Double, Matrix Double, [Int], Double)
+luR m = (l,u,p, fromIntegral s') where
+    r = rows m
+    v = luRaux m
+    lu = reshape r $ subVector 0 (r*r) v
+    s':p = map round . toList . subVector (r*r) (r+1) $ v
+    u = triang r r 0 1`mul` lu
+    l = (triang r r 0 0 `mul` lu) `add` ident r
+    add = liftMatrix2 $ vectorZipR Add
+    mul = liftMatrix2 $ vectorZipR Mul
+
+-- | Complex version of 'luR'.
+luC :: Matrix (Complex Double) -> (Matrix (Complex Double), Matrix (Complex Double), [Int], Complex Double)
+luC m = (l,u,p, fromIntegral s') where
+    r = rows m
+    v = luCaux m
+    lu = reshape r $ subVector 0 (r*r) v
+    s':p = map (round.realPart) . toList . subVector (r*r) (r+1) $ v
+    u = triang r r 0 1 `mul` lu
+    l = (triang r r 0 0 `mul` lu) `add` ident r
+    add = liftMatrix2 $ vectorZipC Add
+    mul = liftMatrix2 $ vectorZipC Mul
+
+extract l is = [l!!i |i<-is]
+
+{- auxiliary function to get triangular matrices
+-}
+triang r c h v = reshape c $ fromList [el i j | i<-[0..r-1], j<-[0..c-1]]
+    where el i j = if j-i>=h then v else 1 - v
+
+{- | rearranges the rows of a matrix according to the order given in a list of integers. 
+
+> > extractRows [3,3,0,1] (ident 4)
+> 0. 0. 0. 1.
+> 0. 0. 0. 1.
+> 1. 0. 0. 0.
+> 0. 1. 0. 0.
+
+-}
+extractRows :: Field t => [Int] -> Matrix t -> Matrix t
+extractRows l m = fromRows $ extract (toRows $ m) l
+
+--------------------------------------------------------------
+
+-- | loads a matrix efficiently from formatted ASCII text file (the number of rows and columns must be known in advance).
+fromFile :: FilePath -> (Int,Int) -> IO (Matrix Double)
+fromFile filename (r,c) = do
+    charname <- newCString filename
+    res <- createMatrix RowMajor r c
+    c_gslReadMatrix charname // mat dat res // check "gslReadMatrix" []
+    --free charname  -- TO DO: free the auxiliary CString
+    return res
+foreign import ccall "gsl-aux.h matrix_fscanf" c_gslReadMatrix:: Ptr CChar -> TM
+
+---------------------------------------------------------------------------