p_external</h4>
<dl>
<dt>
<b>DESCRIPTION</b>
</dt>
<dd>   Provide data from external file interpolated to current model time.
   Data may be local to current processor or global, depending on 
   "init_external_field" flags. </dd>
<br>
<br>
<dt>
<b>INPUT</b>
</dt>
<dd>
<table border="0">
<tr>
<td valign="top" align="left"><tt>index&nbsp;&nbsp;&nbsp;</tt></td><td>   index of external field from previous call to init_external_field <br>&nbsp;&nbsp;&nbsp;<span class="type">[integer]</span></td>
</tr>
<tr>
<td 