title: how to make matrix plot smooth in matlab
body: <p><img src="https://i.stack.imgur.com/ffKLR.jpg" alt="enter image description here"></p>
  
  <p>Like the picture above. How can I make the picture more smooth. Or narrow down the scope of y axis. </p>
  
  <p>The data is from a 2D matrix.</p>
  
  <p>Then I plot with <code>plot('data')</code></p>
  
  <p>Please feel free to throw any ideas.</p>