[R] Graphics device size

[Christos Hatzis]

Dear All,

When working with composite plots many times I have to manually adjust the
graphics display window size to get the best results (in Windows XP).  I can
then find the size of the adjusted window in inches using par("din").

Now I would like to export the adjusted graphs as png's and have them look
as close to the original display as possible.  The problem is that the png
device accepts size arguments in pixels so that I need to convert inches to
pixels.  Is there a way to get the default pixels-per-inch that the windows
device uses?  RSiteSearch("ppi") did not return any helpful hints.

Thanks.
-Christos