ggplot: plotting layers only if certain criteria are met

Question

Is there a method of filtering within ggplot itself? That is, say I want to do this

p <- ggplot(iris, aes(x = Sepal.Width, y = Sepal         


        

Answer 1

apparently layers now accept a function as data argument, so you could use that

pick <- function(condition){
  function(d) d %>% filter_(condition)
}

ggplot(iris, aes(x = Sepal.Width, y = Sepal.Length, species)) +
  geom_point(size = 4, shape = 4) +
  geom_point(data = pick(~Species == "setosa"), colour = "red") +
  geom_point(data = pick(~Species == "versicolor"), shape = 5)