example
library(tidyverse)
# Generate example data
(huron <- data.frame(year = 1875:1972, level1 = as.vector(LakeHuron),
level2 = 1.1*as.vector(LakeHuron)) %>% pivot_longer(
cols=-year,
names_to="group",
values_to = "level"
) %>% mutate(
numbers_below_level = level-9,
numbers_above_level = level +5
)
)
# plot the data
(h <- ggplot(huron, aes(x=year,group=group)) +
geom_ribbon(aes(ymin = numbers_below_level,
ymax =numbers_above_level),
fill = "grey70",alpha=.5) +
geom_line(aes(y = level,colour=group),size=2))