[R] Conditional coloring

[Peter Langfelder]

On Mon, Mar 14, 2011 at 1:06 PM, Pavan G <pavan.namd at gmail.com> wrote:
> Hello All,
> I have a histogram with values above and below 0. I would like to color the
> +ve bars green and -ve bars red. I am plotting data using:
>
> hist(a[,2],breaks=100,main="W3",xlab="Movement towards site (A)")
>
> Can someone please comment on how it can be done?
> Thanks!

See help(hist). The argument "border" lets you color the outline of
the bars. You can use, for example, this code:

h = hist(a[,2],breaks=100)
bor = ifelse(h$mids < 0, "red", "green");
plot(h, border = bor, main="W3",xlab="Movement towards site (A)")

Example with random data:

h = hist(rnorm(1000),breaks=100)
bor = ifelse(h$mids < 0, "red", "green");
plot(h, border = bor, main="W3",xlab="Movement towards site (A)")

HTH,

Peter