variable identifies stage two weights.  The default value is
<code>"weight"</code>.</p></dd>


<dt>xcoord</dt>
<dd><p>Character value providing name of the x-coordinate variable in
the <code>dframe</code> data frame.  For a two-stage sample, the x-coordinate
variable identifies stage two x-coordinates.  Note that x-coordinates are
required for calculation of the local mean variance estimator.  If <code>dframe</code>
is an <code>sf</code> object, this argument is not required (as the geometry column
in <code