title: Frequency and cumulative frequency curve on the same graph in R
body: <p>Is there a way (in R with ggplot or otherwise) to draw frequency and cumulative frequency curves in a single column (two rows) i.e. one top of the other such that a given quartile can be shown on both the curves using straight lines? I hope I am clear on this..</p>
  
  <p>You may use this data..</p>
  
  <pre><code>mydata&lt;-structure(list(speed = c(10, 15, 20, 25, 30, 35, 40, 45, 50),frequency = c(0, 1, 5, 10, 20, 10, 6, 3, 0)), .Names = c("speed","frequency"), row.names = c(NA, -9L), class = "data.frame")
  </code></pre>