Vertical gap between 2 legends in ggplot2/ vertical gap between 2 keys in the same legend-CodePudding

This is a follow up query to this query:

It was made using this code:

library(ggplot2)
df  <- data.frame(x = sample(c("A", "B","C", "D"), 100, replace = TRUE),
                  y = as.factor(sample(c("North", "South", "West", NA), 100, replace = TRUE)))

ggplot(df)  
  aes(x, fill = y, color ="")  
  geom_bar()  
  scale_fill_manual(values  = c("red",
                                "green",
                                "blue"),
                    na.value = "black" ) 
  scale_color_manual(labels="Special value",values="black") 
 guides(fill = guide_legend(order=1),color = guide_legend(title = "", order=2,override.aes = list(fill="white")))

I wish to make the 2 legends appear as if they were levels of one legend.

To do this I wish to make the space between the 2 legends = the space between the keys in the legend on top.

My queries are:

How do I find out how much space is there by default between the keys in the legend on top.
How do I then modify the space between 2 legends to be equal to the answer of 1.

My research so far: I think I need theme(legend.spacing.y) for the second legend.

CodePudding user response：

I might be wrong, but I understand the following from

We can see that there is a problem with the title, fortunately we can get rid of it with title=NULL in guides. By removing it the space between the keys drops to 17 pts.

ggplot(df)  
  aes(x, fill = y, color ="")  
  geom_bar()  
  scale_fill_manual(values  = c("red",
                                "green",
                                "blue"),
                    na.value = "black" ) 
  scale_color_manual(labels="Special value",values="black") 
  guides(fill = guide_legend(order=1),color = guide_legend(title = NULL, order=2,override.aes = list(fill="white")))  
  theme(legend.key = element_rect(size = unit(0.5, 'pt'), color = "purple"),
        legend.margin =  margin(-17,0,0,0,unit="pt"))

Finally, we want to recreate the 0.5pt space between our keys :

ggplot(df)  
  aes(x, fill = y, color ="")  
  geom_bar()  
  scale_fill_manual(values  = c("red",
                                "green",
                                "blue"),
                    na.value = "black" ) 
  scale_color_manual(labels="Special value",values="black") 
  guides(fill = guide_legend(order=1),color = guide_legend(title = NULL, order=2,override.aes = list(fill="white")))  
  theme(legend.margin =  margin(-16.5,0,0,0,unit="pt"))