Legend"</span> )

<span class='kw'>if</span>( <span class='fu'>requireNamespace</span>(<span class='st'>"ggplot2"</span>, <span class='kw'>quietly</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>) ){

  <span class='no'>myplot</span> <span class='kw'>=</span> <span class='kw pkg'>ggplot2</span><span class='kw ns'>::</span><span class='fu'><a href='http://www.rdocumentation.org/packages/ggplot2/topics/qplot'>qplot</a></span>(<span class='no'>Sepal.Length</span>, <span class='no'>Petal.Length</sp