title: Octave: invalid use of script in index expression
body: <p>I want to use a simple code (<code>plot.m</code>) in Octave to plot a figure. My code is the following:</p>
  
  <pre class="lang-matlab prettyprint-override"><code>printf('Plotting Data...\n');
  x = -10:0.1:10;
  plot(x, sin(x));
  </code></pre>
  
  <p>But I get the error message:</p>
  
  <blockquote>
    <p>error: invalid use of script  ex1/plot.m in index expression error: called from plot at line 3 column 1</p>
  </blockquote>
  
  <p>Could you tell me how to solve it? Thanks!</p>