title: Matplotlib minor ticks
body: <p>I am trying to customize the minor ticks in a matplotlib plot. Consider the following code:</p>
  
  <pre><code>import pylab as pl
  from matplotlib.ticker import AutoMinorLocator
  
  fig, ax = pl.subplots(figsize=(11., 7.4))
  
  x = [1,2,3, 4]
  y = [10, 45, 77, 55]
  errorb = [20,66,58,11]
  
  pl.xscale("log")
  
  ax.xaxis.set_minor_locator(AutoMinorLocator(2))
  ax.yaxis.set_minor_locator(AutoMinorLocator(2))
  
  pl.tick_params(which='both', width=1)
  pl.tick_params(which='minor', length=4, color='g')
  pl.tick_params(axis ='both', which='major', length=8, labelsize =20, color='r' )
  
  pl.errorbar(x, y, yerr=errorb)
  #pl.plot(x, y)
  
  pl.show()
  </code></pre>
  
  <p>As far as I understood, <code>AutoMinorLocator(n)</code> is supposed to insert n minor ticks between each major tick, and this is what happens on a linear scale but simply cannot figure out the logic behind the placement of the minor ticks on a logscale. On the top of that, there are much more minor ticks when using <code>errorbar()</code> then when using the simple <code>plot()</code>.</p>