ttps://rdrr.io/r/base/list.html" class="external-link">list</a></span><span class="op">(</span>elevation <span class="op">=</span> <span class="st">"elevation"</span>,</span></span>
<span class="r-in"><span>                 slope <span class="op">=</span> <span class="st">"slope"</span>,</span></span>
<span class="r-in"><span>                 aspect <span class="op">=</span> <span class="st">"aspect"</span><span class="op">)</span></span></span>
<span class="r-in"><span>  <span class="fu">doGRASS</span><spa