></dt>
<dd><p>proportional change in parameters used to numerically estimate
first derivative with central-difference formula (ignored)</p></dd>


<dt id="arg--">...<a class="anchor" aria-label="anchor" href="#arg--"></a></dt>
<dd><p>any additional arguments needed by <code>fct</code></p></dd>

</dl></div>
    <div class="section level2">
    <h2 id="value">Value<a class="anchor" aria-label="anchor" href="#value"></a></h2>
    <p>a list with values</p>
<dl><dt>variance</dt>
<dd><p>estimated variance-covaria