title: How to load specified variables from a mat file
body: <p>I have some mat files with large number of variables saved in it. So I only want to load a subset of the variables. For example, if I want to load </p>
  
  <pre><code>vars = {'x', 'y', 'z'}
  </code></pre>
  
  <p>I know I can explicitly do </p>
  
  <pre><code>a = load('filename.mat', 'x', 'y', 'z')
  </code></pre>
  
  <p>but the <code>vars</code> list can get long and I need to load multiple files, so I can't explicitly list out <code>vars</code> list every time. Is there a way to pass in <code>vars</code> as a argument input?</p>