如何使用geom_rect在ggplot中填充geom_line图下方的区域？

Question

This is my plot:

library(ggplot2)
economics <- economics %>% mutate(year = year(economics$date))

ggplot(economics,aes(year, unemploy))+
  geom_line() +
  geom_rect(aes(xmin = 1970,xmax = 1975,
                     ymin = 0, ymax = unemploy))

I want to fill the area bellow the line plot between the years 1970 and 1975. But its not working.

What am I doing wrong?

Answer 1

You can choose a ymax that makes sense to you. For example, I set ymax = 4800 :

library(ggplot2)
ggplot(economics,aes(year, unemploy))+
        geom_rect(aes(xmin = 1970,xmax = 1975,
                      ymin = 0, ymax = 4800), fill = "lightblue", alpha = .5) +
        geom_line()

Answer 2

The issue is that in ymax we are using the whole column 'unemploy', it should be the max value of 'unemploy' within that range of year

library(ggplot2)
library(dplyr)
library(lubridate)
economics %>%
    mutate(year = year(date)) %>% 
    ggplot(aes(year, unemploy)) + 
        geom_line() +
   geom_rect(aes(xmin = 1970,xmax = 1975,
                      ymin = 0,
        ymax = max(.data[['unemploy']][between(.data[['year']], 1970, 1975)]))) + 
    theme_bw()