title: Format primary and secondary y-axis values on pyplot
body: <p>I am having a hard time formatting a plot with a secondary axis.  I would like to change the font size of the values on my primary and secondary y-axes.  I have tried variations of 'set_ticks...', or 'yticks'  but no luck.  Can someone please give me a hand?  Thanks a lot</p>
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  from matplotlib.ticker import FormatStrFormatter
  
  plt.rcParams[&quot;figure.figsize&quot;] = [16, 9]
  plt.rcParams[&quot;figure.autolayout&quot;] = True
  
  x = [0,1,2,3,4,5,6,7,8,9,10]
  y1 = [0,1,2,3,4,5,6,7,8,9,10]
  y2 = [1000,900,800,700,600,500,400,300,200,100,0]
  
  fig, ax1 = plt.subplots()
  
  ax2 = ax1.twinx()
  ax1.plot(x, y1, 'g-')
  ax2.plot(x, y2, 'b-')
  
  ax1.set_xlabel('increment', size=14)
  
  ax1.set_ylabel('series 1', color='g', fontsize=14)
  ax2.set_ylabel('series 2', color='b', size=14)
  
  plt.title(&quot;This Plot is a Test\n\n&quot;, size=18, color='green')
  plt.suptitle(&quot;\n\nJust a Test&quot;, size=18, color='blue')
  
  ax1.yaxis.set_major_formatter(FormatStrFormatter('%.2f'))
  ax1.yaxis.set_ticks(y1, size=20)
  
  plt.grid()
  plt.show();
  </code></pre>