title: R Density Graph: How can I add a solid line from the x-axis to the top of the density curve
body: <p>I have a density plot graphed using:</p>
  
  <pre><code>plot(density(x))
  </code></pre>
  
  <p>What I am interested in doing is creating a line for something like x = 5 from the x-axis to the corresponding spot on the curve.</p>
  
  <p>Like this:</p>
  
  <p><img src="https://i.stack.imgur.com/RP9fd.gif" alt="example"></p>