ble names  to be grand mean centered, for example to center the variable education by overall mean of
education: <code>~education</code>. Default is NULL which does no centering.</p></dd>


<dt id="arg-max-iteration">max_iteration<a class="anchor" aria-label="anchor" href="#arg-max-iteration"></a></dt>
<dd><p>a optional integer, for non-linear models fit by adaptive quadrature which limits number of iterations allowed
before quitting. Defaults  to 10. This is used because if the likelihood surface is flat,
