="col-md-9 contents">
    <div class="page-header">
    <h1>Create a single panel ID variable out of several</h1>
    <small class="dont-index">Source: <a href='https://github.com/NickCH-K/pmdplyr/blob/master/R/id_variable.R'><code>R/id_variable.R</code></a></small>
    <div class="hidden name"><code>id_variable.Rd</code></div>
    </div>

    <div class="ref-description">
    <p>The pmdplyr library accepts the use of multiple ID variables. However, you may wish to combine these into a single variable, or r