How do I create a categorical scatterplot in R like boxplots?

Question

Does anyone know how to create a scatterplot in R to create plots like these in PRISM\'s graphpad:

Answer 1

If you don't mind using the ggplot2 package, there's an easy way to make similar graphics with geom_boxplot and geom_jitter. Using the mtcars example data:

library(ggplot2)
p <- ggplot(mtcars, aes(factor(cyl), mpg)) 
p + geom_boxplot() + geom_jitter() + theme_bw()

which produces the following graphic:

The documentation can be seen here: http://had.co.nz/ggplot2/geom_boxplot.html