    <td>any point on the beam axis of the arc given as a two element vector [fx, fy] [grid points]</td>
    </tr>    
    
</table>
    
<h2>Optional Inputs</h2>

<p>Optional 'string', value pairs that may be used to modify the default computational settings.</p>

<table cellspacing="0" class="body" cellpadding="4" border="2">
    <colgroup>
        <col width="18%"><col width="18%"><col width="18%"><col width="46%">
    </colgroup>
    
    <thead>
        <tr valign="top">
            <th bgcolor="#B2B2B2