geom_rect on some panels of a facet_wrap

Question

I am trying to get a shaded rectangle on the first three panels in my facet_wrap plot. However, when I use geom_rect for the job, it produces the r

Answer 1

There's a very simple way to do this:

library(ggplot2)
library(plyr)      # for .(...)
ggplot(dfTemp) +
  geom_rect(subset= .(variable<4),aes(xmin = as.Date('2011-02-01', format = '%Y-%m-%d'),
                xmax = as.Date('2011-03-01', format = '%Y-%m-%d'),
                ymin = -Inf,
                ymax = Inf), alpha = 0.2, fill = 'grey') +
  geom_line(aes(x = date, y = value, group = variable, color = factor(variable))) +
  facet_wrap(~variable , scale = 'free', ncol = 1) 

The only difference with your original code is the addition of subset=.(variable<4) to the call to geom_rect(...).