[R] points() colored by value

[Sarah Goslee]

Hi Chris,

On Tue, Nov 15, 2011 at 1:47 PM, Chris82 <rubenbauar at gmx.de> wrote:
> Hi R users,
>
> I want to colored points by their value
>
> for example:
>
> x <- c(1,2,3,4)
> y <- c(1,2,3,4)
> z <- c(2,3,4,9)
>
> y and x are coordinates
>
> z is the value of the coordinates
>
> points(x,y,col= rainbow(z))

In the general sense:
plot(x, y, col=rainbow(length(unique(z)))[as.factor(z)])

converting z to a factor to use as an index is just a quick way to
convert z to sequential values 1,2,3,4 rather than 2,3,4,9 and to
ensure that multiple and unsorted values use the correct color. If z
contains only sequential values, that bit is unnecessary.

I like RColorBrewer for things like this, rather than rainbow, but it
depends on what you're trying to do.

Sarah

> something like that
>
> But haven't found any solution at the moment.
>
> Thanks.
>
> Chris
>
>

-- 
Sarah Goslee
http://www.functionaldiversity.org