Change background color panel based on year in ggplot R

Question

I'm plotting a time series for three different years 2013, 2014, 2015.

require(quantmod)
require(ggplot2)
getSymbols("AAPL", from='2013-01-1')
aapl.df = data.frame(date=time(AAPL), coredata(AAPL.Close))
ggplot(data=aapl.df, aes(x=date, y=AAPL.Close, group=1))+geom_line()

How do I plot the closing price in ggplot such that each year has different background color tiles on the plot?

Answer 1

We can use geom_rect for separating the backgrounds.

ggplot()+
  geom_rect(aes(xmin = as.Date("2015-01-01"),
            xmax = as.Date("2015-12-31"),
                ymin = -Inf, ymax = Inf, fill = '2015'), alpha = .2)+
  geom_rect(aes(xmin = as.Date("2014-01-01"),
            xmax = as.Date("2014-12-31"),
                ymin = -Inf, ymax = Inf, fill = '2014'), alpha = .2)+
  geom_rect(aes(xmin = as.Date("2013-01-01"),
            xmax = as.Date("2013-12-31"),
                ymin = -Inf, ymax = Inf,fill = '2013'), alpha = .2)+
  geom_line(data=subset(aapl.df, date < '2016-01-01'),
            aes(x=date, y=AAPL.Close, group=1))+
  scale_fill_brewer(palette = 'Dark2', name = 'Year')+
  theme_bw()

A few posts were used in this solution: geom_rect and alpha and using geom_rect to add recessions.