Increase the size of the legend keys

We want to increase the size of the legend keys and split the legend over 3 columns, of a ggplot object called p.

Code

By expliciting the package name:

#!/usr/bin/R

p +
    ggplot2::guides(color = ggplot2::guide_legend(override.aes = list(size = 5),
                                                  ncol = 3))

Without the package name:

#!/usr/bin/R

library(ggplot2)

p +
    guides(color = guide_legend(override.aes = list(size = 5),
                                ncol = 3))