Distributions.hs

{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE TypeSynonymInstances #-}

-- | This file contains the functions for plotting distributions using Gnuplot.  The interface is still under heavy construction, so it's not very well documented as of yet.

module HLearn.Gnuplot.Distributions
    where

import HLearn.Algebra
import HLearn.Models.Distributions

import qualified Data.Vector.Unboxed as VU

import Control.Monad
import System.IO
import System.Process

data PlotParams = PlotParams
    { dataFile :: FilePath
    , gnuFile :: FilePath
    , picFile :: FilePath
    , plotPoints :: [Double]
    }

class PlottableDistribution dist where
    genPlotPoints :: dist -> [Double]

instance PlottableDistribution (KDE Double) where
    genPlotPoints (SGJust kde) = VU.toList $ samplePoints $ params kde

genPlotParams :: (PlottableDistribution dist) => String -> dist -> PlotParams
genPlotParams str dist = PlotParams
    { dataFile = str++".dat"
    , gnuFile  = str++".gnu"
    , picFile  = str++".ps"
    , plotPoints = genPlotPoints dist
    }

defPlotParams = PlotParams
    { dataFile = "hlearn-distributions.dat"
    , gnuFile = "hlearn-distributions.gnu"
    , picFile = "hlearn-distributions.ps"
    , plotPoints = [-5..5]
    }
    
plotDistribution :: (Distribution dist Double Double) => PlotParams -> dist -> IO ()
plotDistribution params dist = do
    
    -- Create data file
    putStrLn "Creating data file..."
    datah <- openFile (dataFile params) WriteMode
    forM_ (plotPoints params) $ \x -> do
--     forM_ (map (/10) [-50..50]) $ \x -> do
        hPutStrLn datah $ show (x::Double) ++ " " ++ show (pdf dist x::Double)
    hClose datah
    
    -- Create gnuplot file
    putStrLn "Plotting data"
    gnuh <- openFile (gnuFile params) WriteMode
    hPutStrLn gnuh $ "set terminal postscript \"Times-Roman\" 25"
    hPutStrLn gnuh $ "set output \"" ++ (picFile params) ++ "\""
    hPutStrLn gnuh $ "unset xtics; unset ytics; unset key"
    hPutStrLn gnuh $ "set border 0; set xzeroaxis lt 1; set yzeroaxis lt 1"
    hPutStrLn gnuh $ "plot '"++(dataFile params)++"' using 1:2 lt 1 lw 4 lc rgb '#ccccff' with filledcurves, \\"
    hPutStrLn gnuh $ "     '"++(dataFile params)++"' using 1:2 lt 1 lw 4 lc rgb '#0000ff' with lines"
    hClose gnuh
    
    -- Run gnuplot, creating picture
    system $ "gnuplot "++(gnuFile params)
    putStrLn "done."
    return ()
    
-- testL = [1,1.1,1.2,0,5,-3,2,1,2.5,2.9::Double]
-- kde = train' (KDEParams 1 (VU.fromList $ map (/10) [-50..50::Double]) (KernelBox Gaussian)) testL :: KDE Double
-- 
-- pdfL = sequence_ $ do
--     x <- map (/10) [-50..50]
--     let y = pdf kde x :: Double
--     seq y (return ())
--     return $ putStrLn $ (show (x::Double)) ++ " " ++ show y