title: Plotting densities in R
body: <p>So, I am plotting densities (histograms). For example:</p>
  
  <pre><code>d &lt;- density(table[table$position==2,]$rt)
  </code></pre>
  
  <p>But, I want to plot multiple densities on the same plot. For instance, I also want to plot</p>
  
  <pre><code>density(table[table$position==3,]$rt)
  density(table[table$position==4,]$rt)
  density(table[table$position==5,]$rt)
  </code></pre>
  
  <p>Furthermore, I want to specify the center point for each of these densities. </p>
  
  <p>Another way to ask this question is, how can I manually shift a density plot over by a certain number of x units? (for instance, increase all x values by 5)</p>