title: Setting xticks in pandas bar plot
body: <p>I came across this different behaviour in the third example plot below. Why am I able to correctly edit the x-axis' ticks with <code>pandas</code> <code>line()</code> and <code>area()</code> plots, but not with <code>bar()</code>? What's the best way to fix the (general) third example?</p>
  
  <pre><code>import numpy as np
  import pandas as pd
  import matplotlib.ticker as ticker
  import matplotlib.pyplot as plt
  
  x = np.arange(73,145,1)
  y = np.cos(x)
  
  df = pd.Series(y,x)
  ax1 = df.plot.line()
  ax1.xaxis.set_major_locator(ticker.MultipleLocator(10))
  ax1.xaxis.set_minor_locator(ticker.MultipleLocator(2.5))
  plt.show()
  
  ax2 = df.plot.area(stacked=False)
  ax2.xaxis.set_major_locator(ticker.MultipleLocator(10))
  ax2.xaxis.set_minor_locator(ticker.MultipleLocator(2.5))
  plt.show()
  
  ax3 = df.plot.bar()
  ax3.xaxis.set_major_locator(ticker.MultipleLocator(10))
  ax3.xaxis.set_minor_locator(ticker.MultipleLocator(2.5))
  plt.show()
  </code></pre>