 in which they appear in <code>data</code>.</p>
    </div>

    <div id="ref-usage">
    <div class="sourceCode"><pre class="sourceCode r"><code><span><span class="fu">gf_line</span><span class="op">(</span></span>
<span>  object <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  gformula <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  data <span class="op">=</span> <span class="cn">NULL</span>,</span>
<span>  <span class="va">...</span>,</span>
<span>  <span class