R ggplot with multiple legends, reduce space between two legends

Question

I have a ggplot with two different legends (two different spatial features) that I would like to combine. They do NOT require any additional text, as irl this is a map and map legends can be combined.

REPREX

ggplot(iris)+
 geom_point(aes(x=Petal.Length,y=Sepal.Length, color=Species, size=Petal.Width))+
 guides(color=guide_legend(title=NULL, byrow=T), 
       size=guide_legend(title=NULL,byrow=T))+
 theme(legend.spacing.y=unit(0.5,"lines"))

So how do I remove the space between the two legends to make it "look like" there is only one legend.

I've tried title=element_blank() and that doesn't change much (except the printing order of the legends, oddly enough).

Answer 1

Besides legend.spacing you could reduce or remove the margins via legend.margin:

library(ggplot2)

ggplot(iris) +
  geom_point(aes(x = Petal.Length, y = Sepal.Length, color = Species, size = Petal.Width)) +
  guides(
    color = guide_legend(title = NULL, byrow = T),
    size = guide_legend(title = NULL, byrow = T)
  ) +
  theme(
    legend.spacing.y = unit(0, "lines"),
    legend.margin = margin(0, 0, 0, 0)
  )