Read matrix from CSV file and convert to Matrix (Hmatrix)

TextMatrix.hs

{-# LANGUAGE OverloadedStrings #-}

-- | Converts a matrix represented as text to Hmatrix Matrix. Used GHC 7.4, Hmatrix 0.14.
module Main where

import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Data.Text (Text,splitOn,lines)
import Data.Text.Read (double)
import Data.Packed.Matrix (Matrix,fromLists)

asMatrix :: [[Text]] -> Matrix Double
asMatrix xs = let f = map (fix.double) in fromLists $ map f xs

fix :: Either String (Double,Text) -> Double
fix e = case e of
  Right (d,t) -> d
  _           -> 0.0

main :: IO ()
main = do
  contents <- TIO.readFile "data.txt"
  putStr $ show $ asMatrix $ map (splitOn ",") $ T.lines contents