examples/axis/log.py

   1 # Certainly logarithmic axes are supported in PyX. By playing with
   2 # partitioners and texters, you can easily change the base.
   3 #
   4 # It is left as an exercise to the reader to create a automatic
   5 # partitioner for logarithmic axes with base 2.
   6
   7 import math
   8 from pyx import *
   9
  10 p = path.curve(0, 0, 3, 0, 1, 4, 4, 4)
  11
  12 log2parter = graph.logparter([graph.preexp(graph.frac(1), 4),
  13                               graph.preexp(graph.frac(1), 2)])
  14 log2texter = graph.exponentialtexter(nomantissaexp=r"{2^{%s}}",
  15                                      mantissamax=graph.frac(2))
  16
  17 c = canvas.canvas()
  18 c.insert(graph.pathaxis(p,
  19                         graph.logaxis(min=1, max=1024)))
  20 c.insert(graph.pathaxis(p.transformed(trafo.translate(4, 0)),
  21                         graph.logaxis(min=1, max=1024, parter=log2parter)))
  22 c.insert(graph.pathaxis(p.transformed(trafo.translate(8, 0)),
  23                         graph.logaxis(min=1, max=1024, parter=log2parter,
  24                                       texter=log2texter)))
  25 c.writetofile("log")