I\'m plotting a fairly simple chart using ggplot2 0.9.1.
x <- rnorm(100, mean=100, sd = 1) * 1000000
y <- rnorm(100, mean=100, sd = 1) * 1000000
df <- d
More generally, you can control some nice parameters using the "scales" package. One of its functions is number_format().
library(ggplot2)
library(scales)
p <- ggplot(mpg, aes(displ, cty)) + geom_point()
For formatting your numbers, you can use the function number_format(). It offers some nice possibilities, such as controlling the number of decimals (here 2 decimals) and your decimal mark (here ',' instead of '.')
p + scale_y_continuous(
labels = scales::number_format(accuracy = 0.01,
decimal.mark = ','))