design/palettetest.py

   1 #!/usr/bin/env python
   2 # -*- coding: ISO-8859-15 -*-
   3 import sys
   4 sys.path.insert(0, "..")
   5
   6 import math
   7 from math import *
   8 from pyx import *
   9 from pyx.graph import axis, data
  10
  11 # define some functions for the color values:
  12 def red(x):   return 2*x*(1-x)**5 + 3.5*x**2*(1-x)**3 + 2.1*x*x*(1-x)**2 + 3.0*x**3*(1-x)**2 + x**0.5*(1-(1-x)**2)
  13 def green(x): return 1.5*x**2*(1-x)**3 - 0.8*x**3*(1-x)**2 + 2.0*x**4*(1-x) + x**4
  14 def blue(x):  return 5*x*(1-x)**5 - 0.5*x**2*(1-x)**3 + 0.3*x*x*(1-x)**2 + 5*x**3*(1-x)**2 + 0.5*x**6
  15
  16 # use the implemented converter for the grey value:
  17 def grey(x): return color.rgb(red(x), green(x), blue(x)).grey().color["gray"]
  18
  19 # plot the color values
  20 g = graph.graphxy(width=10, ratio=1)
  21 g.plot(data.function("y(x)=red(x)",   min=0, max=1, context=locals()), [graph.style.line([color.rgb.red])])
  22 g.plot(data.function("y(x)=green(x)", min=0, max=1, context=locals()), [graph.style.line([color.rgb.green])])
  23 g.plot(data.function("y(x)=blue(x)",  min=0, max=1, context=locals()), [graph.style.line([color.rgb.blue])])
  24 g.plot(data.function("y(x)=grey(x)",  min=0, max=1, context=locals()))
  25
  26 # plot the colors
  27 n = 200
  28 x = 0
  29 for i in range(n):
  30     t = i * 1.0 / (n-1)
  31     g.fill(path.rect(x, -2, 10.5/(n-1), 1), [color.rgb(red(t), green(t), blue(t))])
  32     x += 10.0 / n
  33
  34 g.writeEPSfile("palettetest", paperformat=document.paperformat.A4)
  35 g.writePDFfile("palettetest")
  36