Question

I have 6 datasets for which I need to plot boxplot using R in a single plot. Out of 6 , 2 are of more importance so I want to highlight them by shading their background . Is it possible to selectively shade background behind the boxplot for few leaving others as it is using boxplot() function of R ?

Answer 1

You can try to use function rect() and give coordinates of lower left and upper right corner and color. Argument lty=0 ensures that there are no borders. Function boxplot() is used twice because rect() will hide first boxplots. add=TRUE in second boxplot() ensures that plot is made on the same graphic.

a<-rep(c("g1","g2","g3","g4","g5","g6"),each=10)
b<-rnorm(60)    
boxplot(b~a)
rect(0.5,-3,1.5,3,col="grey75",lty=0)
rect(2.5,-3,3.5,3,col="grey75",lty=0)
boxplot(b~a,add=TRUE)