title: Matplotlib specify axes value inside an interval
body: <p>I have a csv with 200 data points. If I plot it, the x-axis will take default values from 0 to 200. However, 4 data points correspond to each event, so I would like to have values from 0 to 50 on the x-axis. </p>
  
  <p>This is what I have now</p>
  
  <pre><code>import matplotlib.pyplot as plt
  
  fig1 = plt.figure()
  ax1 = fig1.add_subplot(111)
  
  ax1.plot(val, color='blue', label='t1')
  ax1.plot(val2, color='red', label='t2')
  ax1.plot(val3, color='green', label='t3')
  ax1.plot(val5, color='magenta', label='t4')
  
  plt.axis([0,200,0,0.8])
  
  plt.xlabel('Values')
  plt.ylabel('Events')
  ax1.legend(loc='upper right')
  </code></pre>
  
  <p>Any idea how I can modify this to effectively divide the numbers on the x-axis by 4 ? </p>