pan class="fu">ggplot</span><span class="op">(</span><span class="va">example_data</span>,
       <span class="fu">aes</span><span class="op">(</span>y <span class="op">=</span> <span class="va">weight</span>, axis1 <span class="op">=</span> <span class="va">grp1</span>, axis2 <span class="op">=</span> <span class="va">grp2</span>, axis3 <span class="op">=</span> <span class="va">grp3</span><span class="op">)</span><span class="op">)</span> <span class="op">+</span> 
  <span class="fu"><a href="../reference