[R] How to shadow 'power' area?

[Marc Schwartz]

On Mon, 2007-06-25 at 22:50 +0200, Andrej Kastrin wrote:
> Dear all,
> 
> Suppose I plot two normal distributions (A and B) side by side and add 
> vertical line which hipotheticaly represent alpha value; e.g.:
> 
> x <- seq(-3.5,5, length=1000)
> y <- dnorm(x)
> # Plot distribution A
> plot(y~x, type='l',axes=F,xlab="",ylab="",lwd=2)
> # Plot distribution B
> y2 <- dnorm(x-1.5)
> lines(y2~x,lwd=2)
> # Plot vertical line for alpha value
> abline(h=0)
> segments(qnorm(.5)+1.5,0,qnorm(.5)+1.5,dnorm(qnorm(.5)))
> text(2,0.2,"Power")
> 
> Now I want to shadow area labeled as "Power". Any suggestion how to do 
> that using 'polygon' function?
> 
> Thanks in advance for any suggestion.
> 
> Andrej

See the latter section of this post:

http://tolstoy.newcastle.edu.au/R/help/03b/2475.html

and in turn, ?polygon

HTH,

Marc Schwartz