title: How to change size of QPixmap?
body: <p>I am write a paint program.</p>
  
  <pre><code>pix = QPixmap(600,500);  // set size to 600X500
  </code></pre>
  
  <p>How to change size after this? Someting like:</p>
  
  <pre><code>pix.setSize(800,600);  // Change size to 800X600
  </code></pre>