r - Easier way to plot the cumulative frequency distribution in ggplot?

Question

I'm looking for an easier way to draw the cumulative distribution line in ggplot.

I have some data whose histogram I can immediately display with

qplot (mydata, binwidth=1);

I found a way to do it at http://www.r-tutor.com/elementary-statistics/quantitative-data/cumulative-frequency-graph but it involves several steps and when exploring data it's time consuming.

Is there a way to do it in a more straightforward way in ggplot, similar to how trend lines and confidence intervals can be added by specifying options?

Answer 1

The new version of ggplot2 (0.9.2.1) has a built-in stat_ecdf() function which let's you plot cumulative distributions very easily.

qplot(rnorm(1000), stat = "ecdf", geom = "step")

Or

df <- data.frame(x = c(rnorm(100, 0, 3), rnorm(100, 0, 10)),
             g = gl(2, 100))
ggplot(df, aes(x, colour = g)) + stat_ecdf()

Code samples from ggplot2 documentation.