case where <code>method</code> is <code>"approx"</code>. Note that the default value
for <code>rule</code> is 1, which will inhibit extrapolation beyond the observed
pressure range. This is a change from the behaviour previous to May 8, 2017,
when a <code>rule</code> of 2 was used (without stating so as an argument).</p></dd>


<dt id="arg-e">e<a class="anchor" aria-label="anchor" href="#arg-e"></a></dt>
<dd><p>is an expansion coefficient used to calculate the local neighbourhoods
for the <code>"boxcar"</co