title: How to boxplot a subset of data versus the whole set in R?
body: <p>I am using <code>bwplot</code> and I want to construct a boxplot of a subset of my data based on a factor variable, against the whole dataset.</p>
  
  <p>For example:</p>
  
  <pre><code>library(MASS)
  library(lattice)
  data &lt;- Cars93[,c("Manufacturer", "Price")] 
  bwplot(data$Price~data$Manufacturer)
  </code></pre>
  
  <p>But rather than plotting each manufacturer, I just wanted to have two plots, one for say Chevrolet, and the other the entire dataset (including Chevrolet) - how would I do this?</p>
  
  <p>Thanks!</p>