title: Calculate width of text string in default font/size
body: <p>Is it at all possible to calculate the width size (in inches) of a particular string in the default font ( <code>par()$family</code> ) , and default size ( <code>par()$ps</code> ).  </p>
  
  <p>Calculating the height seems relatively simple:</p>
  
  <pre><code>par()$ps * 1/72
  </code></pre>
  
  <p>The challenge with width is that it is dependent on the string itself.  A string of i's "iiiiii" is smaller than a string of o's "ooooooo"</p>