title: add more labels to the x axis python matplotlib
body: <p>this is my original graph:
  <img src="https://i.stack.imgur.com/e6RDV.png" alt="enter image description here"></p>
  
  <p>I didn't change the xticklabels or anything, I only did <code>plot(x,y)</code>, the labels are automatically generated according to the x values.</p>
  
  <p>However I want to change the x label to [0,24,48,72....480,504]</p>
  
  <p>This is what I did</p>
  
  <pre><code>ax.plot(x1,y1)
  
  xlabel =[]
  xinterval = np.arange(0,504,24) 
  ax.set_xticks=(xinterval)
  ax.set_xticklabels(xinterval)
  </code></pre>
  
  <p>And the result is:
  <img src="https://i.stack.imgur.com/jshWz.png" alt="enter image description here"></p>
  
  <p>which is obviously wrong, could anyone help?</p>