al vector of group identifiers. For <code>plot.slca</code> it is
a single integer group identified.</p></dd>

  <dt>weights</dt>
<dd><p>Optional vector of sample weights</p></dd>

  <dt>Xdes</dt>
<dd><p>Design matrix for \(x_{ijh}\) with \( q_{ihjv}\) entries.
Therefore, it must be an array with four dimensions referring to
items (\(i\)), categories (\(h\)), latent classes (\(j\)) and
\(\lambda\) parameters (\(v\)).</p></dd>

  <dt>Xlambda.init</dt>
<dd><p>Initial \(\lambda_x\) parameters</p></dd>

  <dt>Xl