Create Scatterplot in R with Legend Inside Plot Area Using ggplot2

Legends help us to differentiate the values of the response variable while creating the scatterplot. In this way, we can understand how one level of a factor variable affects the response variable. The legend is preferred to be positioned at left bottom, top right, top left, and bottom right. We can use theme function to position the legends.

Example

Consider the below data frame −

> set.seed(99)
> x1<-rnorm(20)
> x2<-rnorm(20,2)
> F<-factor(c("A","B","C","D"))
> df<-data.frame(x1,x2,F)
> library(ggplot2)

Creating the plot with different legend positions −

Consider the below data frame −

> ggplot(df, aes(x=x1, y=x2, colour=F)) + geom_point(aes(colour=F)) +
+ theme(legend.justification = c(1, 0), legend.position = c(1, 0))

Output

> ggplot(df, aes(x=x1, y=x2, colour=F)) + geom_point(aes(colour=F)) +
+ theme(legend.justification = c(1, 1), legend.position = c(1, 1))

Output

> ggplot(df, aes(x=x1, y=x2, colour=F)) + geom_point(aes(colour=F)) +
+ theme(legend.justification = c(0, 1), legend.position = c(0, 1))

Output

> ggplot(df, aes(x=x1, y=x2, colour=F)) + geom_point(aes(colour=F)) +
+ theme(legend.justification = c(0, 0), legend.position = c(0, 0))

Output