examples/axis/texter.py

   1 # Texters create the label strings written to the ticks. There are
   2 # texters available for decimal numbers without and with an
   3 # exponential part as well as fractions. Internally, the partitioning
   4 # is based on fractions to avoid any rounding problems.
   5 #
   6 # Although we could modify axis.linear into a piaxis "inplace", we
   7 # define a special piaxis below to give an impression, how easy
   8 # alternative default settings can be implemented. A more advanced
   9 # task would be to add an appropriate special partitioner for a
  10 # piaxis.
  11
  12 import math
  13 from pyx import *
  14 from pyx.graph import axis
  15
  16 class piaxis(axis.linear):
  17
  18     def __init__(self, divisor=math.pi,
  19                  texter=axis.texter.rational(suffix="\pi"), **kwargs):
  20         axis.linear.__init__(self, divisor=divisor, texter=texter, **kwargs)
  21
  22
  23 p = path.path(path.moveto(0, 0), path.curveto(3, 0, 1, 4, 4, 4))
  24
  25 c = canvas.canvas()
  26 c.insert(axis.pathaxis(p, axis.linear(min=0, max=10)))
  27 c.insert(axis.pathaxis(p.transformed(trafo.translate(4, 0)),
  28                        axis.linear(min=0, max=1e5)))
  29 c.insert(axis.pathaxis(p.transformed(trafo.translate(8, 0)),
  30                        piaxis(min=0, max=2*math.pi)))
  31 c.writeEPSfile("texter")
  32 c.writePDFfile("texter")