title: regarding using "clear all;" in functions
body: <p>I have several MATLAB scripts, e.g., fun1, fun2,...etc  There can have dependency relationships among them. For instance, fun1 can call fun2 and fun2 can call fun3.   </p>
  
  <p>In order to remove unnecessary variables, should I put “clear all;” at the head of every functions.</p>
  
  <pre><code>function x1 = fun1(input1)
  clear all;
  ...
  </code></pre>
  
  <p>Will this cause any potential issue, such as removing useful variables?</p>