>Vector of discretized trait distribution. This vector is expanded in all
dimensions by using the <code><a href="https://rdrr.io/r/base/expand.grid.html" class="external-link">base::expand.grid</a></code>
function. If a user specifies a design matrix <code>theta.kDES</code> of transformed
\(\bold{\theta}_p\)
values (see Details and Examples), then <code>theta.k</code> must be a matrix, too.</p></dd>

  <dt>theta.kDES</dt>
<dd><p>An optional design matrix. This matrix will differ from the ordinary
theta grid