This matrix dataset is used by the PostScript driver to determine the
imageable region of the output based on a specified paper size. The matrix
has one row per paper size and four columns. Each row gives the X and Y
coordinates for the lower left and upper right corners of the area of the
paper onto which the PostScript printer can print. The coordinates are
specified in the PostScript default coordinate system of 72 units per inch.
During device startup, this matrix is used in combination with the current
ps.options(paper)
setting to specify the default
ps.options(region)
.
In order to find the imageable region for a new PostScript printer,
send the following PostScript job to the printer:
%!
/buf 30 string def
/pnum {buf cvs show} def
/nl {currentpoint 16 sub exch pop 72 exch moveto} def
/Helvetica findfont 14 scalefont setfont
clippath pathbbox
72 360 moveto
4 -1 1 {-1 roll pnum nl} for
showpage
The four numbers that get printed may be used directly, in the order printed,
as the
region
argument for the
ps.options
function.
# Default paper size? ps.options()$paper # Default region for the default paper size? ps.paper.regions[ps.options()$paper,]