title: In matplotlib setting minor ylabel invisible fails after zoom in
body: <p>I creat a plot with major and minor y ticks. I set evry 5'th minor ticks invisible to avoid intereference of the major and minor ticks. It works fine when I creat my plot but after I zoom in it gets broken. I use python 2.7.11 with Canopy 1.7.4.3348 as IDE.</p>
  
  <p>I creat ticks for the y axis as next:</p>
  
  <ol>
  <li>major ticks are set for y = n +- 0.5 where n is element of Z, where Z labels integers</li>
  <li>minor ticks are set for y = n +- 0.1 where n is element of Z, where Z labels integers</li>
  <li>to avoid interferenc with the major ticks evry 5'th element of the minor ticks are set invisible</li>
  </ol>
  
  <p>The code which implement this is the next:</p>
  
  <pre><code>import numpy as np
  import matplotlib as mpl
  import matplotlib.pyplot as plt
  
  mpl.rcParams['text.usetex'] = True
  
  x = np.linspace(0,2*np.pi,200)
  y = np.sin(x)
  
  majorLocatorX  = MultipleLocator(0.5)
  majorFormatterX = FormatStrFormatter('%.1f')
  
  majorLocatorY  = MultipleLocator(0.5)
  minorLocatorY  = MultipleLocator(0.1)
  majorFormatterY = FormatStrFormatter('%.1f')
  minorFormatterY = FormatStrFormatter('%.1f')
  
  fig1 = plt.figure(figsize=(12,12))
  ax1 = fig1.add_subplot(1,1,1)
  ax1.set_xlabel(r'$x$')
  ax1.set_ylabel(r'$\sin(x)$')
  ax1.set_xlim([-0.03,2*np.pi+0.03])
  ax1.set_ylim([-1.03,1.03])
  ax1.xaxis.set_major_locator(majorLocatorX)
  ax1.xaxis.set_major_formatter(majorFormatterX)
  ax1.xaxis.set_minor_locator(minorLocatorX)
  ax1.yaxis.set_major_locator(majorLocatorY)
  ax1.yaxis.set_major_formatter(majorFormatterY)
  ax1.yaxis.set_minor_locator(minorLocatorY)
  ax1.yaxis.set_minor_formatter(minorFormatterY)
  for label in ax1_1.yaxis.get_ticklabels('minor')[1::5]:
      label.set_visible(False)
  ax1.plot(x,y,label=r'$\sin(x)$')
  ax1.legend(loc='best',fontsize=12.0)
  
  plt.show()
  </code></pre>
  
  <p>Before I zoom in I have the plot:
  <a href="https://i.stack.imgur.com/xBnmu.png" rel="nofollow noreferrer">The "original" plot.</a>.</p>
  
  <p>After I zoom in I get the plot:
  <a href="https://i.stack.imgur.com/ubk6R.png" rel="nofollow noreferrer">The zoomed in plot.</a>.</p>
  
  <p>Any help is highly appreciated!</p>