I recently saw folks were using P.map with the painter of ppm selected
were having problems with scaling up size of area. I have recently modified
p.map's behavior to give larger output on our HP paintjet XL.
Tip 1: I have found the scale (which p.map prompts you for) to mean
how many panels do you want your output to consist of.
Inches is meaningless when you print to a ppm file, because
target print pixel size is unknown. Scaling can be done in
pnmscale.
A panel is the maximum size of the image that p.map can produce.
(if you ask for your output map to be scale to say, 6 panels
you should have 6 printouts to cut up and paste together to
make one big map. But they all get jamed into the paint.ppm
file, of which I have not found a way to pull more then just
the first out. There should be 6 paint.ppm files, or something.)
Tip 2: I use ppmtopj, since it can handle a ppm file directly rather
than converting it to an xwd file. This is in the
pbmplus10dec91 distribution. Which can be found on
wuarchive.wustl.edu in /graphics/graphics/packages/pbmplus
Tip 3: (the best) P.select sets your printer up for you. Besides
just setting your PAINTER envariable this program runs a
shell script in ~grass/etc/paint/driver.sh/xxx where xxx is the
type of printer you selected. In the ppm shell script
there are important envariables, two can help you print
larger images then the p.map default. WIDTH and HEIGHT.
HEIGHT and WIDTH were set at 800 and 600 (I forgot the original
setting). On the HPPaintjet XL with 11x17 inch paper we can
print at 180 dpi. So to print large 11x11 inch square images
I set these to 2340 and 2340. So I will get a large HI resolution
print of a soils map. I then choose a scale of one panel on
the p.map prompt, and get a 11x11 inch print. I print a square
map so I can rotate the final image without worrying about clipping
off parts of the map. The state of Oregon on our maps comes out
on an angle of the declination, so I rotate it -79 degress to
get it in landsape mode.
The following script is a simple one containing the steps I go through:
p.map
xv paint.ppm
ppmcrop paint.ppm | pnmrotate -79 > p.p
xv p.p
ppmtopj p.p | lpr -s -Ppablo
Tip 4: The above change will produce large output paint.ppm files.
(my soil map was 24 megs) We have added to the /etc/printcap entry
for our color printer a mx#0 setting that allows for unlimited large
prints, but the /etc/spool space is limited. With multiple users
printing this will get filled up, so I suggest you do not pipe
to lpr, but rather convert you ppm to a pj file then link
the file to the spooler (lpr -s).
FYI.
Kevin Currans Dept of Entomology,
Oregon State University
Internet: kcurrans@bcc.orst.edu Corvallis, Oregon U.S.A. (503)737-5515