GSL.LinearAlgebra reorganized

1 files changed, 42 insertions, 0 deletions

diff --git a/packages/hmatrix/src/Numeric/LinearAlgebra/IO.hs b/packages/hmatrix/src/Numeric/LinearAlgebra/IO.hs
new file mode 100644
index 0000000..d2278ee
--- /dev/null
+++ b/packages/hmatrix/src/Numeric/LinearAlgebra/IO.hs
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+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Numeric.LinearAlgebra.IO
+-- Copyright   :  (c) Alberto Ruiz 2007-14
+-- License     :  GPL
+-- Maintainer  :  Alberto Ruiz
+-- Stability   :  provisional
+--
+-----------------------------------------------------------------------------
+
+module Numeric.LinearAlgebra.IO (
+    saveMatrix,
+    fwriteVector, freadVector, fprintfVector, fscanfVector,
+    fileDimensions, loadMatrix, fromFile
+) where
+
+import Data.Packed
+import Numeric.GSL.LinearAlgebra
+import System.Process(readProcess)
+
+
+{- |  obtains the number of rows and columns in an ASCII data file
+      (provisionally using unix's wc).
+-}
+fileDimensions :: FilePath -> IO (Int,Int)
+fileDimensions fname = do
+    wcres <- readProcess "wc" ["-w",fname] ""
+    contents <- readFile fname
+    let tot = read . head . words $ wcres
+        c   = length . head . dropWhile null . map words . lines $ contents
+    if tot > 0
+        then return (tot `div` c, c)
+        else return (0,0)
+
+-- | Loads a matrix from an ASCII file formatted as a 2D table.
+loadMatrix :: FilePath -> IO (Matrix Double)
+loadMatrix file = fromFile file =<< fileDimensions file
+
+-- | Loads a matrix from an ASCII file (the number of rows and columns must be known in advance).
+fromFile :: FilePath -> (Int,Int) -> IO (Matrix Double)
+fromFile filename (r,c) = reshape c `fmap` fscanfVector filename (r*c)
+