If I understand correctly what A. Ezhil asked for, polygons won't help here. For coloring the individual points check ?points and use subsets, e.g.
plot(x,y) points(x[x>y-1],y[x>y-1], col="red") or something similar. Petr John Kane napsal(a): > Here is a recent posting by Petr Klasterecky that > does not seem to be on the archive yet that may help. > ---------------------------------------------- > > 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 > ----------------------------------------------- > --- A Ezhil <[EMAIL PROTECTED]> wrote: > >> Dear All, >> >> I am using the following commands to do the scatter >> plot of two vectors, say X and Y. >> >> plot(X,Y, col="blue") >> abline(a=1,b=1, col="red") >> abline(a=-1,b=1, col="green") >> >> I would like to split the scatter plot into 3 part >> with 3 different colors: (i) points lies between 2 >> lines, (ii) points above line 1, and (iii) points >> below line 2. I am struggling to do this. I would >> greatly appreciate any help in doing this. >> >> Thanks in advance. >> >> Kind regards, >> Ezhil >> >> ______________________________________________ >> 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. >> > > ______________________________________________ > 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.