saving graphs; jpeg(), bitmap()

Trying Sys.setenv(DISPLAY=":0.0")  or sys.setenv(DISPLAY=":0.0") in my 
R gives the same message that the function doesn't work... (Simon 
asked me to that this)

*bangs his head against a wall*
my mistake - it's

Sys.putenv(DISPLAY=":0.0")

in C you can use both setenv and putenv, in csh it's setenv so I mix 
those things up :P

As of Apple's X11 - look in Applications -> Utilities and there should 
be X11. But XDarwin and other X11 are usually mutually exclusive, so I 
doubt that you have Apple's X11. I have no idea why someone would 
install XDarwin instead of Apple's X11 nowadays, it makes no sense to 
me, but maybe someone can explain that.

I couldn't find the file ghostscript.

The "file" is just "gs" - GhostScript is just the name of the program 
is called.

c) Stephan suggests "set the DISPLAY var on your own". I don't know 
what this means. I guess that is to link my X11 to R but I don't know 
how to do this.

it's what I tried to make you with the Sys.putenv ;)

d) I couldn't understand whether there is not a way besides the menu 
to save pdf files. Or all those methods are also dependent on the 
problems from above?

I'm not sure, but AFAIK the pdf device is independent of X (see ?pdf in 
R).

Cheers,
Simon