title: Join data points on boxplot with lines ggplot2
body: <p>I'm trying to visualize paired sets of data points on the following graphs:</p>
  
  <pre><code>ggplot(grid.mag.ROIcontrols.allRuns, aes(Model,Grid_Magnitude)) +
    geom_boxplot(aes(fill=Model),outlier.shape = NA,alpha=0.6) +
    geom_point(aes(fill=Model),size=2,shape=21,position=position_jitterdodge(0.2)) +
    geom_line(aes(group=Side)) +
    facet_grid(~Side,scales = "free") +
    scale_fill_brewer(palette="GnBu") +
    labs(title = "Average Grid Magnitude, pm vs al EC")
  </code></pre>
  
  <p>Lines are joining the points between <code>alLeft6</code>/<code>pmLeft6</code> and between <code>alRight6</code>/<code>pmRight6</code>. </p>
  
  <p>However <code>geom_line</code> with the group variable that I need doesn't work - it adds vertical lines and one horizontal line between data points, when I need one horizontal line for each of the 10 pairs.</p>
  
  <p>Without <code>geom_line</code>: 
  <img src="https://i.stack.imgur.com/e09fZ.png" alt="without geom_line"></p>
  
  <p>With <code>geom_line</code>: 
  <img src="https://i.stack.imgur.com/xJt3v.png" alt="with geom_line"></p>
  
  <p>PS: Sorry, I don't know how to share the raw data...</p>