al information.</p>
    </div>
    <div id="details">
    <h2>Details</h2>
    <p>A distance matrix that contains the hydrologic distance
between any two sites in <code>SSN</code> object is needed to fit a spatial
statistical model using the tail-up and tail-down autocovariance
functions described in Ver Hoef and Peterson (2010). These models
are implemented in R via <code class="command">ssn_lm</code> and <code class="command">ssn_glm</code> in
the<code>SSN2</code> package. The hydrologic distance informat