title: How to add boxplots to scatterplot with jitter
body: <p>I am using following commands to produce a scatterplot with jitter:</p>
  
  <pre><code>ddf = data.frame(NUMS = rnorm(500), GRP = sample(LETTERS[1:5],500,replace=T))
  library(lattice)
  stripplot(NUMS~GRP,data=ddf, jitter.data=T)
  </code></pre>
  
  <p>I want to add boxplots over these points (one for every group). I tried searching but I am not able to find code plotting all points (and not just outliers) and with jitter. How can I solve this. Thanks for your help.</p>