What do you mean by background? Maybe this is enough: plot(seq(-3,3,.01), dnorm(seq(-3,3,.01)), type="n", xlab="x", ylab="f(x)", main="Normal density") polygon(x=c(-4,0,0,-4), y=c(-1,-1,.5,.5), col="red") polygon(x=c(4,0,0,4), y=c(-1,-1,.5,.5), col="blue") lines(seq(-3,3,.01), dnorm(seq(-3,3,.01)), type="l", lwd=2)
Play a little bit with the polygon margins to get what you need. You can even generate them automatically based on your data. Petr yannig goude napsal(a): > hi, > I want to add different colors on the background of a classical plot. Each > color is associated to an interval of the x axis. > example: the background is red on the interval [1,10], blue on [11,20]. > I try the rect function but it isn't appropriate for the background. > Can any one can help me please? > best regards. > > > > --------------------------------- > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Petr Klasterecky Dept. of Probability and Statistics Charles University in Prague Czech Republic ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.