Customize background to highlight ranges of data in ggplot [duplicate]

Answer 1

You can add the "bars" with geom_rect() and setting ymin and ymax values to -Inf and Inf. But according to @sc_evens answer to this question you have to move data and aes() to geom_point() and leave ggplot() empty to ensure that alpha= of geom_rect() works as expected.

ggplot()+
  geom_point(data=df,aes(x=y*abs(x),y=y),alpha=.2,size=5) +
  geom_rect(aes(xmin=-0.1,xmax=0.1,ymin=-Inf,ymax=Inf),alpha=0.1,fill="green")+
  geom_rect(aes(xmin=-0.25,xmax=-0.1,ymin=-Inf,ymax=Inf),alpha=0.1,fill="orange")+
  geom_rect(aes(xmin=0.1,xmax=0.25,ymin=-Inf,ymax=Inf),alpha=0.2,fill="orange")+
  theme_bw() +
  coord_cartesian(xlim = c(-.5,.5),ylim=c(-1,1))

Answer 2

You may try annotate, which takes vectors of xmin and xmax values.

ggplot(df,aes(x,y)) +
  geom_point(aes(y*abs(x)), alpha =.2, size = 5) +
  annotate("rect", xmin = c(-0.1, -0.25, 0.1), xmax = c(0.1, -0.1, 0.25),
           ymin = -1, ymax = 1,
           alpha = 0.2, fill = c("green", "orange", "orange")) +
  theme_bw() +
  coord_cartesian(xlim = c(-.5,.5),ylim=c(-1,1))