title: Matplotlib interactive navigation zoom-to-rectangle button doesn't work
body: <p>I have this Python code to plotting a figure:</p>
  
  <pre><code>matplotlib.rcParams['axes.unicode_minus'] = False
  fig = plt.figure()
  ax = fig.add_subplot(111)
  </code></pre>
  
  <p>I draw each plot running a loop along x and y like this:</p>
  
  <pre><code>ax.plot(x, y, dotFormat)
  ax.errorbar(x, y, yerr=errorStd, fmt=dotFormat)
  </code></pre>
  
  <p>Finally, I set the axes and show the chart with the interactive navigation:</p>
  
  <pre><code>ax.grid(True)
  ax.set_title(chartTitle)
  
  fontsize=10
  
  ax.set_ylabel(yLabel, fontsize=fontsize+2)
  ax.set_xlabel(xLabel+'\n', fontsize=fontsize+2)
  
  ax.set_yticklabels(ax.get_yticks(), fontsize=fontsize)
  ax.set_xticks(range(len(xMinorLabels)), minor=True) 
  ax.set_xticklabels(xMinorLabels, minor=True, rotation=90, fontsize=fontsize-5) 
  ax.set_xticks(xMajorPosition, minor=False) 
  ax.set_xticklabels(xMajorLabels, minor=False, rotation=90, fontsize=fontsize-4)
  
  plt.show()
  </code></pre>
  
  <p>If I use the tool zoom-to-rectangle and the Y-axis doesn't work property, because the same dot before zooming in is under 5, and after zooming in it is over 5.</p>
  
  <p>What is happening with the y-axis when I use the zoom tool? Is a bug in the interactive navigation of matplotlib library? Without this tool, the library is useless for huge charts.</p>
  
  <p>Thanks in advance!</p>