title: Invalid index error in Scilab when trying to access array element
body: <p>I'm not sure why I can't do this in Scilab.</p>
  
  <pre><code>--&gt;foo=zeros(500);
  
  --&gt;foo(300)
           !--error 21 
  Invalid index.
  </code></pre>
  
  <p>Why do I get the 'Invalid index' error? I thought I had initialized foo as an array with 500 elements, each of which was set to 0?</p>