title: Multiple Groups in geom_density() plot
body: <p>I am trying to plot 3 groups in one geom_density()plot.</p>
  
  <p>The data is in long format:</p>
  
  <pre><code>MEI Count   Region
  -2.031  10  MidWest
  -1.999  0   MidWest
  -1.945  15  MidWest
  -1.944  1   MidWest
  -1.875  6   MidWest
  -1.873  10  MidWest
  -1.846  18  MidWest
  </code></pre>
  
  <p>Region is the variable, so there is a South and NorthEast value as well, code is below:</p>
  
  <pre><code>ggplot(d, aes(x=d$MEI, group=d$region)) + 
    geom_density(adjust=2) + 
    xlab("MEI") +
    ylab("Density")
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/XbYO0.png" alt="Plot but with only one density not 3"></p>
  
  <p>a step closer</p>
  
  <p><img src="https://i.stack.imgur.com/agHbn.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/ZPvs9.png" alt="enter image description here"></p>