script to test difference between linear locator scripts

linearlocatortest.py

# -*- coding: utf-8 -*-
"""
Created on Tue Mar 29 15:49:38 2016

@author: showard
"""

from __future__ import (absolute_import, division, print_function,
                        unicode_literals)
import matplotlib.ticker

import math
from matplotlib import transforms as mtransforms



class LinearLocator2(matplotlib.ticker.LinearLocator):
    def view_limits(self, vmin, vmax):
        'Try to choose the view limits intelligently'

        if vmax < vmin:
            vmin, vmax = vmax, vmin

        if vmin == vmax:
            vmin -= 1
            vmax += 1

        if True:
            exponent, remainder = divmod(math.log10(vmax - vmin),
                                         math.log10(max([self.numticks-1, 1])))
            if remainder < 0.5:
                exponent -= 1
            scale = max([self.numticks-1, 1]) ** (-exponent)
            print(scale, scale*vmin, math.floor(scale*vmin))
            vmin = math.floor(scale * vmin) / scale
            vmax = math.ceil(scale * vmax) / scale

        return mtransforms.nonsingular(vmin, vmax)

lineartest = matplotlib.ticker.LinearLocator()
lineartest2 = LinearLocator2()

numticks = 13
vmin, vmax = [20, 90]
lineartest.numticks = numticks
lineartest2.numticks = numticks
vmin1, vmax1 = lineartest.view_limits(vmin, vmax)
vmin2, vmax2 = lineartest2.view_limits(vmin, vmax)
print("numticks: "+str(numticks)+", data min: "+str(vmin)+", data max: "+str(vmax))
print("Current:")
print(lineartest.tick_values(vmin1, vmax1))
print("Proposed:")
print(lineartest2.tick_values(vmin2, vmax2))