Data import from octave / text file
Dear all, I want to read numeric data in vector / matrix format generated by octave. As I haven't seen any octave specific libraries yet (only matlab), I'm tyrying the way via ascii - file. The folloing file log.txt contains three signal traces in the three columns (time, signal 1, signal 2) 0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9 I got the following bit of code compiled with ghc: import System.IO main = do text <- readFile "./log.txt" putStrLn text putStrLn "SecondLot" let m = read text :: [[Double]] putStrLn (show m) putStrLn "Finish" Reading text works, but not reading text into m. The Output: 0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9 SecondLot signalImport: Prelude.read: no parse Any suggestions ? - Thanks in advance. -- 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.
Hi, On 15/06/11 12:13, kaffeepause73 wrote:
let m = read text :: [[Double]] signalImport: Prelude.read: no parse
read :: String -> [[Double]] -- expects Haskell syntax try something like: parse :: String -> [[Double]] -- expects plainer syntax parse = map (map read . words) . lines Claude -- http://claudiusmaximus.goto10.org
On Wed, Jun 15, 2011 at 04:13:49AM -0700, kaffeepause73 wrote:
The folloing file log.txt contains three signal traces in the three columns (time, signal 1, signal 2)
0 30 9 0.1 30 9 0.2 30 9
let m = read text :: [[Double]]
SecondLot signalImport: Prelude.read: no parse
Instances of Read tends to expect the format that Show would output. In the case of lists, it's [elem1,elem2,elem3]. You can either modify your exporter to output values in the format that read expects, or you could use a combination of the functions 'lines', 'words' and 'read' to split the input into a list of lines, split each line into a list of words, and finally use read to go from word to Double. -- Lars Viklund | zao@acc.umu.se
read :: String -> [[Double]] can't read this format. It expects "[[0,30,9],[0.1,30,9],...]" use this code let m = map f text :: [[Double]] f a = map g $ lines a g a = map read $ words a 15.06.2011 15:13, kaffeepause73 пишет:
Dear all,
I want to read numeric data in vector / matrix format generated by octave. As I haven't seen any octave specific libraries yet (only matlab), I'm tyrying the way via ascii - file.
The folloing file log.txt contains three signal traces in the three columns (time, signal 1, signal 2)
0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9
I got the following bit of code compiled with ghc:
import System.IO
main = do text<- readFile "./log.txt" putStrLn text
putStrLn "SecondLot"
let m = read text :: [[Double]] putStrLn (show m)
putStrLn "Finish"
Reading text works, but not reading text into m. The Output:
0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9
SecondLot signalImport: Prelude.read: no parse
Any suggestions ? - Thanks in advance.
-- 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.
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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 = takerows 1 m putStrLn (show t) putStrLn "Finish" kaffeepause73 wrote:
Dear all,
I want to read numeric data in vector / matrix format generated by octave. As I haven't seen any octave specific libraries yet (only matlab), I'm tyrying the way via ascii - file.
The folloing file log.txt contains three signal traces in the three columns (time, signal 1, signal 2)
0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9
I got the following bit of code compiled with ghc:
import System.IO
main = do text <- readFile "./log.txt" putStrLn text
putStrLn "SecondLot"
let m = read text :: [[Double]] putStrLn (show m)
putStrLn "Finish"
Reading text works, but not reading text into m. The Output:
0 30 9 0.1 30 9 0.2 30 9 0.3 30 9 0.4 30 9 0.5 30 9 0.6000000000000001 30 9 0.7000000000000001 30 9 0.8 30 9 0.9 30 9 1 30 9
SecondLot signalImport: Prelude.read: no parse
Any suggestions ? - Thanks in advance.
-- 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.
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.
Hi, try Numeric.Container.loadMatrix. Regards, Philipp On 15.06.2011 14:59, kaffeepause73 wrote:
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.
participants (5)
-
Claude Heiland-Allen -
kaffeepause73 -
Lars Viklund -
Philipp Schuster -
Victor Gorokgov