</dt>
<dd><p>Simulation seed for initial parameters. The default
of <code>NULL</code> corresponds to a random seed.</p></dd>

<dt>progress</dt>
<dd><p>An optional logical indicating whether the function
    should print the progress of iteration in the estimation process.</p></dd>

<dt>PEM</dt>
<dd><p>Logical indicating whether the P-EM acceleration should be
applied (Berlinet &amp; Roland, 2012).</p></dd>

<dt>PEM_itermax</dt>
<dd><p>Number of iterations in which the P-EM method should be
applied.</p></dd>