title: Using i and j as variables in MATLAB
body: <p><code>i</code> and <code>j</code> are very popular variable names (see e.g., <a href="https://stackoverflow.com/questions/4137785/why-are-variables-i-and-j-used-for-counters">this question</a> and <a href="https://stackoverflow.com/questions/454303/why-are-we-using-i-as-a-counter-in-loops">this one</a>).</p>
  <p>For example, in loops:</p>
  <pre><code>for i=1:10,
      % Do something...
  end
  </code></pre>
  <p>As indices into a matrix:</p>
  <pre><code>mat(i, j) = 4;
  </code></pre>
  <p>Why <em>shouldn't</em> they be used as variable names in MATLAB?</p>