 time-point,
the value can be replace by <code>NaN</code>. Do not inpute data as the
package is explicitely designed to be robust to missing values.</p>
<p>Here is an example of <code>5</code> observations of <code>2</code>
variables. Taken on <code>3</code> individual separated in
<code>2</code> goups, covering <code>3</code> time-points:</p>
<div class="sourceCode" id="cb1"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="co"># Metadata</span></span></code></pre></div>
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