code refactoring

1 files changed, 169 insertions, 0 deletions

diff --git a/lib/Graphics/Plot.hs b/lib/Graphics/Plot.hs
new file mode 100644
index 0000000..9f719ab
--- /dev/null
+++ b/lib/Graphics/Plot.hs
@@ -0,0 +1,169 @@
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Graphics.Plot
+-- Copyright   :  (c) Alberto Ruiz 2005
+-- License     :  GPL-style
+-- 
+-- Maintainer  :  Alberto Ruiz (aruiz at um dot es)
+-- Stability   :  provisional
+-- Portability :  uses gnuplot and ImageMagick
+--
+-- Very basic (and provisional) drawing tools.
+--
+-----------------------------------------------------------------------------
+
+module Graphics.Plot(
+
+    gnuplotX, mplot,
+
+    plot, parametricPlot, 
+
+    splot, mesh, mesh', meshdom,
+
+    matrixToPGM, imshow,
+
+) where
+
+import Data.Packed.Vector
+import Data.Packed.Matrix
+import LinearAlgebra.Linear(outer)
+import GSL.Vector(FunCodeS(Max,Min),toScalarR)
+import Data.List(intersperse)
+import System
+import Data.IORef
+import System.Exit
+import Foreign hiding (rotate)
+
+
+size = dim
+
+-- | Loads a real matrix from a formatted ASCII text file 
+--fromFile :: FilePath -> IO Matrix
+--fromFile filename = readFile filename >>= return . readMatrix read
+
+-- | Saves a real matrix to a formatted ascii text file
+toFile :: FilePath -> Matrix Double -> IO ()
+toFile filename matrix = writeFile filename (unlines . map unwords. map (map show) . toLists $ matrix)
+
+------------------------------------------------------------------------
+
+
+-- | From vectors x and y, it generates a pair of matrices to be used as x and y arguments for matrix functions.
+meshdom :: Vector Double -> Vector Double -> (Matrix Double , Matrix Double)
+meshdom r1 r2 = (outer r1 (constant 1 (size r2)), outer (constant 1 (size r1)) r2)
+
+gnuplotX :: String -> IO ()
+gnuplotX command = do {system cmdstr; return()} where
+    cmdstr = "echo \""++command++"\" | gnuplot -persist"
+
+datafollows = "\\\"-\\\""
+
+prep = (++"e\n\n") . unlines . map (unwords . (map show))
+
+
+{- | Draws a 3D surface representation of a real matrix.
+
+> > mesh (hilb 20)
+
+In certain versions you can interactively rotate the graphic using the mouse.
+
+-}
+mesh :: Matrix Double -> IO ()
+mesh m = gnuplotX (command++dat) where
+    command = "splot "++datafollows++" matrix with lines\n"
+    dat = prep $ toLists $ m
+
+mesh' :: Matrix Double -> IO ()
+mesh' m = do
+    writeFile "splot-gnu-command" "splot \"splot-tmp.txt\" matrix with lines; pause -1"; 
+    toFile "splot-tmp.txt" m
+    putStr "Press [Return] to close the graphic and continue... "
+    system "gnuplot -persist splot-gnu-command"
+    system "rm splot-tmp.txt splot-gnu-command"
+    return ()
+
+{- | Draws the surface represented by the function f in the desired ranges and number of points, internally using 'mesh'.
+
+> > let f x y = cos (x + y) 
+> > splot f (0,pi) (0,2*pi) 50    
+
+-}
+splot :: (Matrix Double->Matrix Double->Matrix Double) -> (Double,Double) -> (Double,Double) -> Int -> IO () 
+splot f rx ry n = mesh' z where
+    (x,y) = meshdom (linspace n rx) (linspace n ry)
+    z = f x y
+
+{- | plots several vectors against the first one -}
+mplot :: [Vector Double] -> IO ()
+mplot m = gnuplotX (commands++dats) where
+    commands = if length m == 1 then command1 else commandmore
+    command1 = "plot "++datafollows++" with lines\n" ++ dat
+    commandmore = "plot " ++ plots ++ "\n"
+    plots = concat $ intersperse ", " (map cmd [2 .. length m])
+    cmd k = datafollows++" using 1:"++show k++" with lines"
+    dat = prep $ toLists $ fromColumns m
+    dats = concat (replicate (length m-1) dat)
+
+
+
+
+
+
+mplot' m = do
+    writeFile "plot-gnu-command" (commands++endcmd)
+    toFile "plot-tmp.txt" (fromColumns m)
+    putStr "Press [Return] to close the graphic and continue... "
+    system "gnuplot plot-gnu-command"
+    system "rm plot-tmp.txt plot-gnu-command"
+    return ()
+ where
+    commands = if length m == 1 then command1 else commandmore
+    command1 = "plot \"plot-tmp.txt\" with lines\n"
+    commandmore = "plot " ++ plots ++ "\n"
+    plots = concat $ intersperse ", " (map cmd [2 .. length m])
+    cmd k = "\"plot-tmp.txt\" using 1:"++show k++" with lines"
+    endcmd = "pause -1"
+
+-- apply several functions to one object
+mapf fs x = map ($ x) fs
+
+{- | Draws a list of functions over a desired range and with a desired number of points 
+
+> > plot [sin, cos, sin.(3*)] (0,2*pi) 1000
+
+-}
+plot :: [Vector Double->Vector Double] -> (Double,Double) -> Int -> IO ()
+plot fs rx n = mplot (x: mapf fs x)
+    where x = linspace n rx  
+
+{- | Draws a parametric curve. For instance, to draw a spiral we can do something like:
+
+> > parametricPlot (\t->(t * sin t, t * cos t)) (0,10*pi) 1000
+
+-}
+parametricPlot :: (Vector Double->(Vector Double,Vector Double)) -> (Double, Double) -> Int -> IO ()
+parametricPlot f rt n = mplot [fx, fy]
+    where t = linspace n rt
+          (fx,fy) = f t
+
+
+-- | writes a matrix to pgm image file
+matrixToPGM :: Matrix Double -> String
+matrixToPGM m = header ++ unlines (map unwords ll) where
+    c = cols m
+    r = rows m
+    header = "P2 "++show c++" "++show r++" "++show (round maxgray :: Int)++"\n"
+    maxgray = 255.0
+    maxval = toScalarR Max $ flatten $ m
+    minval = toScalarR Min $ flatten $ m
+    scale = if (maxval == minval) 
+        then 0.0
+        else maxgray / (maxval - minval)
+    f x = show ( round ( scale *(x - minval) ) :: Int )
+    ll = map (map f) (toLists m)
+
+-- | imshow shows a representation of a matrix as a gray level image using ImageMagick's display.
+imshow :: Matrix Double -> IO ()
+imshow m = do
+    system $ "echo \""++ matrixToPGM m ++"\"| display -antialias -resize 300 - &"
+    return ()