"co"># and a common effect of X1 and its interaction with time over classes </span></span></span>
<span class="r-in"><span><span class="co"># (in fixed). </span></span></span>
<span class="r-in"><span><span class="co"># The variance of the random intercept and slope are assumed to be equal </span></span></span>
<span class="r-in"><span><span class="co"># over classes (nwg=F).</span></span></span>
<span class="r-in"><span><span class="co"># The covariate X3 predicts the class membership (in classmb).</span><