Greg, Thanks for this - it works really well!
One (hopefully final!) question I have is, is there any way of preventing overplotting? I'm finding that many of the red points are being obscured by the greens - I've tried making the point sizes small (cex=0.1) but this doesn't fully solve the problem. Or even, is there a way of changing the order of which the points are plotted? Thanks again, Steve > From: [EMAIL PROTECTED] > To: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL > PROTECTED]; [EMAIL PROTECTED] > CC: [email protected] > Date: Thu, 18 Sep 2008 10:56:05 -0600 > Subject: RE: [R] Use of colour in plots > > 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: [email protected] >> 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 = >> >> ______________________________________________ >> [email protected] 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. _________________________________________________________________ Discover Bird's Eye View now with Multimap from Live Search ______________________________________________ [email protected] 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.
