ass="anchor" aria-label="anchor" href="#arguments"></a></h2>


<dl><dt id="arg-x-y">x, y<a class="anchor" aria-label="anchor" href="#arg-x-y"></a></dt>
<dd><p>a vector of x and y locations.</p></dd>


<dt id="arg-z">z<a class="anchor" aria-label="anchor" href="#arg-z"></a></dt>
<dd><p>a vector of z values, one at each (x,y) location.</p></dd>


<dt id="arg-w">w<a class="anchor" aria-label="anchor" href="#arg-w"></a></dt>
<dd><p>a optional vector of weights at the (x,y) location.  If not
supplied, then a wei