ggplot: position legend in top left

Question

I have a plot made with ggplot2 and I'd like to get the legend positioned in the top left corner.

legend.position = "top" gets me a legend positioned above the plot, but centered:

legend.position = c(0,1) gets the legend in the top left, but it floats over the other plot elements:

Know how to get that legend up in the top left without having it float? I tried declaring the legend height, but no dice. Do I have to adjust the size and position of the title and plot area?

Thanks!

Answer 1

It can be done with legend.justification using predefined options.

library(ggplot2)

ggplot(mtcars, aes(x=factor(cyl), y=mpg, fill=factor(cyl))) + 
  geom_boxplot() +
  ggtitle("No title needed") +
  theme(legend.position='top', 
        legend.justification='left',
        legend.direction='horizontal')

Answer 2

How about something like this -- not sure if there's a way to avoid the "hack" of \n\n\n in the call to ggtitle()

library(ggplot2)

ggplot(mtcars, aes(x = factor(cyl), y = mpg, fill = factor(cyl))) + 
  geom_boxplot() +
  ggtitle("A Title for Plot\n\n\n") +
  theme(
           legend.position = c(0, 1), 
      legend.justification = c(0, 0),
          legend.direction = "horizontal"
  )