ode>, <code>"spherical"</code>, <code>"exponential"</code>,
<code>"mariah"</code>, <code>"epa"</code>, and <code>"none"</code>.</p></dd>


<dt>de</dt>
<dd><p>The spatially dependent (correlated) random error variance. Commonly referred to as
a partial sill.</p></dd>


<dt>range</dt>
<dd><p>The correlation parameter.</p></dd>


<dt>known</dt>
<dd><p>A character vector indicating which covariance parameters are to be
assumed known. The value <code>"given"</code> is shorthand for assuming all
covariance parame