ass="co">## subjid:     53638     90001  </span></span>
<span><span class="co">##    age:     12.00     19.00  </span></span>
<span><span class="co">##    fev:     3.118     5.793  </span></span>
<span><span class="co">## height:     65.50     74.00  </span></span>
<span><span class="co">##    sex:     2.000     2.000  </span></span>
<span><span class="co">##  smoke:     1.000     2.000</span></span></code></pre>
<p>Since we input a dataframe, we can see that all variables have the
same number of elements g