ode R"><span><span class="co"># This DEM does not have many drops</span></span>
<span><span class="fu"><a href="../reference/fd.html">fd</a></span><span class="op">(</span><span class="va">dem1</span>, method <span class="op">=</span> <span class="st">"hvar"</span>, lvec <span class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="fl">1</span>, <span class="fl">0.5</span>, <span class="fl">0.25</span>, <span class=