an>
<span class="r-in"><span class="fu">setup_deriv_control</span><span class="op">(</span>method <span class="op">=</span> <span class="st">"simple"</span><span class="op">)</span> <span class="co"># will speed up computations</span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> An object of class "deriv_control"</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Slot ".FUN":</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> function (func, x, method = "Richardson", s