R help - Jul 2009 - Shading the area between lines

Hi,

I have a graph with seven parallel horizontal lines. Is it possible to
shade the area between two adjacent lines?

Thank you in advance,
Hannu

Hi,

You could use ?rect

x = 1:5
 y=1:5
 plot(x,y,t="n",xaxs="i")
 abline(h=y)

xlims = range(x)

y.rect = matrix(rep(y,each=2)[-c(1, 2*length(y))], ncol=2, byrow=T)
x.rect = matrix(rep(xlims), ncol=2,nrow=nrow(y.rect), byrow=T)

cols = 1:4

rect(x.rect[,1], y.rect[,1], x.rect[,2], y.rect[,2],col=cols)

and more generally ?polygon

HTH,

baptiste

2009/7/4 Hannu Kahra <hkahra@gmail.com>
> Hi,
>
> I have a graph with seven parallel horizontal lines. Is it possible to
> shade the area between two adjacent lines?
>
> Thank you in advance,
> Hannu
>
> ______________________________________________
> 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.
>


-- 

_____________________________

Baptiste Auguié

School of Physics
University of Exeter
Stocker Road,
Exeter, Devon,
EX4 4QL, UK

Phone: +44 1392 264187

http://newton.ex.ac.uk/research/emag
______________________________

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Hannu Kahra wrote:
> Hi,
>
> I have a graph with seven parallel horizontal lines. Is it possible to
> shade the area between two adjacent lines?
>
>   
Hi Hannu,
Easy if you know the endpoints of the lines.

plot(rep(1,2),type="l",ylim=c(0,8))
for(i in 1:6) {
 lines(rep(i+1,2))
 polygon(c(1,1,2,2),c(i,i+1,i+1,i),col=i)
}

Jim