r - How to plot one variable in ggplot?

Question

I'm searching but still can't find an answer to a quite simple question - how can we produce a simple dot plot of one variable with ggplot2 in R?

with plot command this is very simple:

plot(iris$Sepal.Length, type='p')

But when I'm trying to pass one variable to qplot and specifying geom="point", I'm getting an error "Error in UseMethod("scale_dimension")".

How can we make a plot like this but with ggplot2?

Answer 1

You can manually create an index vector with seq_along.

library(ggplot2)

qplot(seq_along(iris$Sepal.Length), iris$Sepal.Length)