Some R code designed for ggplot2 0.8.9 is not compatible with ggplot2 0.9.0, and today the ggplot2 web site has outdated documentation which gives this broken example:
> x <- rnorm(10) * 100000 > y <- seq(0, 1, length = 10) > p <- qplot(x, y) > p + scale_y_continuous(formatter = "percent") Error in continuous_scale(c("y", "ymin", "ymax", "yend", "yintercept", : unused argument(s) (formatter = "percent")
require(scales) p <- qplot(x, y) p + scale_y_continuous(labels=percent)
The transition guide has more details about transformations such as log, log10, sqrt, etc. and formats such as comma, percent, dollar, date, scientific, etc.