I have created a plot of the Sepal.Length and the Sepal.Width (using the iris dataset) with ggplot2.
ggplot(iris, aes(x = Sepal.Width, y = Sepal.Length, col =
Using annotate:
ggplot(iris, aes(x = Sepal.Width, y = Sepal.Length, col = Species)) + geom_point() + annotate("point", x = 5.6, y = 3.9, colour = "blue")