ions</a></li>
<li class="chapter" data-level="1.3" data-path="introduction.html"><a href="introduction.html#why"><i class="fa fa-check"></i><b>1.3</b> Why R and <strong>ggplot2</strong></a></li>
</ul></li>
<li class="chapter" data-level="2" data-path="the-layered-grammar-of-graphics.html"><a href="the-layered-grammar-of-graphics.html"><i class="fa fa-check"></i><b>2</b> The Layered Grammar of Graphics</a>
<ul>
<li class="chapter" data-level="2.1" data-path="the-layered-grammar-of-graphics.html"><a href="the