Using geom_rect for time series shading in R

Question

I am trying to shade a certain section of a time series plot (a bit like recession shading - similarly to the graph at the bottom of this article on recession shading in exc

Answer 1

Its a bit easier using annotate and also note that the bounds for the rectange can be specified as shown:

ggplot(a_series_df, aes(month, big)) + 
    geom_line() +
    annotate("rect", fill = "red", alpha = 0.5, 
        xmin = 1924, xmax = 1928 + 11/12,
        ymin = -Inf, ymax = Inf) +
    xlab("time")

This would also work:

library(zoo)

z <- read.zoo(a_series_df, index = 2)
autoplot(z) + 
    annotate("rect", fill = "red", alpha = 0.5, 
        xmin = 1924, xmax = 1928 + 11/12,
        ymin = -Inf, ymax = Inf) + 
    xlab("time") +
    ylab("big")

Either one gives this: