geom_rect_cm: Geom Layer for Rectangle with Absolute Size
In plothelper: New Plots Based on 'ggplot2' and Functions to Create Regular Shapes

Description Usage Arguments Details Examples

This layer uses centimeter as unit to draw rectangles so that the size and shape will not be influenced by the coordinate systems (even when a polar system is used).

geom_rect_cm(
  mapping = NULL,
  data = NULL,
  stat = "identity",
  position = "identity",
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE,
  ...
)

`mapping`	aes mapping.
`data`	data.
`stat`	stat.
`position`	position.
`na.rm`	logical, whether to remove NA values.
`show.legend`	whether to show legend.
`inherit.aes`	logical, whether to inherit aes from ggplot().
`...`	additional parameters.

Accepted properties are:

(1) width width in centimeter.
(2) height height in centimeter.
(3) color color of the outline.
(4) fill color inside the shape.
(5) alpha alpha of color and fill.
(6) size line width of outline.
(7) linetype line type.
(8) hjust horizontal adjustment, default is 0.5 which means no adjustment.
(9) vjust vertical adjustment, default is 0.5 which means no adjustment.
(10) x x coordinates of middle points.
(11) y y coordinates of middle points.

library(ggplot2)
ggplot()+xlim(-0.5, 10.5)+
	geom_rect_cm(aes(x=1: 10, y=rep(4, 10)), fill="red", height=rep(1: 2, each=5), 
		vjust=rep(c(0, 0.5), 5))+
	geom_point(aes(x=1: 10, y=rep(4, 10)), color="green")