Try something like: > x <- runif(25) > y <- rnorm(25) > z <- rnorm(25, 3*x) > plot(x, y, col=ifelse( z > 1.25, 'red', 'green') )
Does this help, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare [EMAIL PROTECTED] 801.408.8111 > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > project.org] On Behalf Of Steve Murray > Sent: Thursday, September 18, 2008 8:14 AM > To: ONKELINX, Thierry; Petr PIKAL; [EMAIL PROTECTED]; > [EMAIL PROTECTED] > Cc: r-help@r-project.org > Subject: Re: [R] Use of colour in plots > > > Jim and all, > > Maybe I've misunderstood ?color.scale (appologies if this is so), but I > don't think this is what I need. I'm not looking to scale the colours > of points, instead I simply want to assign each point a colour (either > red or green) based on it's value in the Urban.Rural column. > > To clarify (but please also see my earlier message if this helps): > > In my dataset (Jan) I have 3 columns of interest: Average Burnt Area > Fraction (ABAF), PopDensity and Urban.Rural. > > I want to plot ABAF against PopDens (which I've had no problems doing) > and then, regardless of the values of ABAF and PopDens, I want to > assign it a colour. The colour each point is given is based on the > corresponding Urban.Rural value on each row. If for each pair of ABAF > and PopDens values the Urban.Rural value on that row is>1.25, then the > point should be coloured red, whereas if it's = > > ______________________________________________ > R-help@r-project.org 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@r-project.org 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.