How to draw a nice arrow in ggplot2

Question

I am creating a ggplot chart where I want to have some arrows between two points. The main task is easily done with geom_line(arrow = arrow()). How

Answer 1

There is a very simple, but somewhat "hacky" solution to this.

The idea is to draw the lines first (at the desired thickness, but no arrowheads), but a little bit shorter (can be calculated in some cases). Then just draw a second line, without changing the size with arrowheads. The resulting overlay will look the way you want.