x, n=50)</code>.</p></dd>


<dt id="arg-xgl-ygl">xgl, ygl<a class="anchor" aria-label="anchor" href="#arg-xgl-ygl"></a></dt>
<dd><p>optional lengths of the x and y grids, to be constructed with
<code><a href="https://rdrr.io/r/base/seq.html" class="external-link">seq()</a></code> spanning the data range.  These values <code>xgl</code> are only
examined if <code>xg</code> and <code>yg</code> are not supplied.</p></dd>


<dt id="arg-xr-yr">xr, yr<a class="anchor" aria-label="anchor" href="#arg-xr-yr"></a></dt