How to position the legend in the bottom left corner and move the title on the right or on the top?

Question

I have been trying to find this question answered before, but I couldn't find it anywhere. I have created a ggplot graph and would like to show a edit: horizontal legend under the plot. The legend should be in the bottom left corner and the title should be on its right or above. I managed to rotate the legend, but I can't get the title to move where I want it. Can anybody help?

My_Theme = theme(
legend.text = element_text(size=12),
legend.title.align =0,
legend.position = "bottom", 
legend.box = "horizontal", 
legend.title = element_text(size=14, vjust=0.5, hjust = 0.3))

This gets me this weird looking legend placement:

I want the legend to move to the left, but have its title on the right or above. At the moment the title blurs in with the legend and makes it hard to read.

Can anybody help? Thanks a lot and nice holidays :)

Answer 1

Using mtcars as example data this could be achieved like so:

1. The position of the title could be set via guide_colorbar and the argument title.position.

2. The legend could be positioned in the bottom left corner using theme options legend.position = "bottom" and legend.justification = "left".

3. For the direction of the legend I was not sure about your desired result. As you said you want a vertical legend I used legend.direction="vertical".

library(ggplot2)

ggplot(mtcars, aes(hp, mpg, color = mpg)) +
  geom_point() +
  labs(color = "I'm a long\nlegend title") +
  guides(color = guide_colorbar(title.position = "top")) +
  theme(
    legend.text = element_text(size=12),
    legend.title.align = 0,
    legend.position = "bottom", 
    legend.justification = "left",
    legend.direction = "vertical",
    legend.title = element_text(size=14, vjust = .5, hjust = .3))