Add bar to bottom of point plot-CodePudding

I am creating a point plot and I wanted to add a bar to the bottom of a point plot. I can't seem to find out how to do this in the ggplot documentation. I was hoping to add at bar the spanned the entire x-axis with a set y-axis value. Here is an example of the data I am working with

d=data.frame(drink=c("coffee","tea","water"), mean=c(5,6,9), lower=c(4.5,5.6,8.7), upper=c(5.5,6.3,9.5))

and here is the code I am using

ggplot()   
  geom_errorbar(data=d, mapping=aes(x=drink, ymin=upper, ymax=lower), width=0.2, size=1, color="blue")   
  geom_point(data=d, mapping=aes(x=drink, y=mean), size=4, shape=21, fill="white")  
  scale_y_continuous(n.breaks = 10)   ylim(0, 12)

Here is what the plot currently looks like

and this is what I want to add

CodePudding user response：

The annotate() function allows you to directly specify a layer without intermediate data.frame. In ggplot2, the -Inf/Inf values for continuous variables indicate to place something at the extremes.

library(ggplot2)

d=data.frame(drink=c("coffee","tea","water"), 
             mean=c(5,6,9), 
             lower=c(4.5,5.6,8.7), 
             upper=c(5.5,6.3,9.5))

ggplot(d)   
  geom_errorbar(
    mapping=aes(x=drink, ymin=upper, ymax=lower), 
    width=0.2, size=1, color="blue")   
  geom_point(
    mapping=aes(x=drink, y=mean), 
    size=4, shape=21, fill="white")  
  scale_y_continuous(n.breaks = 10, limits = c(0, 12))  
  annotate("rect", xmin = -Inf, xmax = Inf, 
           ymin = -Inf, ymax = 1, fill = "black")

^{Created on 2021-09-13 by the reprex package (v2.0.1)}