R help - Jun 2007 - How to shadow 'power' area?

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

Look at the following link:

http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=88 

This should be pretty close to what you want.
HTH

-Christos
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Andrej Kastrin
> Sent: Monday, June 25, 2007 4:51 PM
> To: R-help
> Subject: [R] How to shadow 'power' area?
> 
> 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
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
> 
>

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

You can look at the power.examp function in the TeachingDemos package to
see if it gives you the graph you want, or look at the code to see how
you could modify it to give you the plot you want.

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at intermountainmail.org
(801) 408-8111
 
 
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Andrej Kastrin
> Sent: Monday, June 25, 2007 2:51 PM
> To: R-help
> Subject: [R] How to shadow 'power' area?
> 
> 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
> 
> ______________________________________________
> R-help at stat.math.ethz.ch 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.
>