[R] Scatterplot with the 3rd dimension = color?

Kerry kbrownk at gmail.com
Mon Oct 17 19:59:25 CEST 2011


Oh, I just saw your ggplot example, that works well too. However, it
seems much of the options are hidden for changing the range of colors
or the color types altogether. I'm currently looking through the
ggplot ref manuals.

Thanks,
kb

On Oct 2, 10:42 pm, Ben Bolker <bbol... at gmail.com> wrote:
> Duncan Murdoch <murdoch.duncan <at> gmail.com> writes:
>
>
>
>
>
>
>
>
>
>
>
> > On 11-10-02 1:11 PM, Kerry wrote:
> > > I have 3 columns of data and want to plot each row as a point in a
> > > scatter plot and want one column to be represented as a color gradient
> > > (e.g. larger  values being more red). Anyone know the command or
> > > package for this?
>
> > It's not a particularly effective display, but here's how to do it.  Use
> > rainbow(101) in place of rev(heat.colors(101)) if you like.
>
> > x <- rnorm(10)
> > y <- rnorm(10)
> > z <- rnorm(10)
> > colors <- rev(heat.colors(101))
> > zcolor <- colors[(z - min(z))/diff(range(z))*100 + 1]
> > plot(x,y,col=zcolor)
>
>   or
>
> d <- data.frame(x,y,z)
> library(ggplot2)
> qplot(x,y,colour=z,data=d)
>
>   I agree about the "not particularly effective display"
> comment, but if you have two continuous predictors and
> a continuous response you've got a tough display problem --
> your choices are:
>
>   1. use color, size, or some other graphical characteristic
> (pretty far down on the "Cleveland hierarchy")
>   2. use a perspective plot (hard to get the right viewing
> angle, often confusing)
>   3. use coplots/small multiples/faceting (requires
> discretizing one dimension)
>
> ______________________________________________
> R-h... at r-project.org mailing listhttps://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



More information about the R-help mailing list