r - ggplot2 - highlighting selected points and strange behavior

Question

I want to highlight selected points and encountered some strange behaviour. First some dummy data:

a <- 1:50
b <- rnorm(50)
mydata <- data.frame(a=a         


        

Answer 1

Another solution with gghighlight:

a <- 1:50
b <- rnorm(50)
mydata <- data.frame(a=a,b=b, type = sample(letters, 50, replace = T))

library(gghighlight)
gghighlight_point(mydata, aes(x=a, y=b), label_key = type, 
                  a <= 14 & a >= 10 & b >= 0 , col="red")