[R] Consistent behaviour of for-loop

[Uwe Dippel]

First my excuses if I keep bugging everyone in this list, but I am a 
newbie, and tend to find some behaviour that looks unexpected to me; and 
I would really appreciate to be pointed to some location that allows me 
to understand more about this software. Here is my next question:
 > par(mfrow=c(1,1))
 > qqnorm(rnorm(20))
 > qqmath(rnorm(20))
 > par(mfrow=c(3,4))
 > for(i in 1:12)qqnorm(rnorm(20))
Until here everything works as expected, and the last line prints 12 
samples of qqnorm. However,
 > for(i in 1:12)qqmath(rnorm(20))
is doing nothing at all.

As I wrote, I'd really appreciate the understand where this behaviour 
comes from.

Thanks in advance,

Uwe