Hey guys, thanks for the very quick help. The code works and looks like: (any tips regards speed and memory usage ?) import System.IO import Data.Array import Data.Packed.Matrix parse :: String -> [[Double]] -- expects plainer syntax parse = map (map read . words) . lines main = do -- read and show plain text text <- readFile "./log.txt" putStrLn text -- read and show parsed list of lists putStrLn "parsed list of lists" let m = parse text putStrLn (show m) -- convert to matrix and show let a = fromLists m putStrLn (show a) -- cuts out first row to get signal let t = takeColumns 1 a putStrLn (show t) putStrLn "Finish" -- View this message in context: http://haskell.1045720.n5.nabble.com/Data-import-from-octave-text-file-tp449... Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com.