Malcolm Williamson malcolm at cast.uark.edu
Fri Jul 7 08:00:00 EDT 1995

Ok, I'll try to avoid putting my foot in my mouth this time around. I 
have obviously overlooked the setcolor command in ps.map, and I can't 
comment on its functionality since I've never tried it. However, changing 
raster values for a map in ps.map is quite easy; you've got to alter the 
actual GRASS colortable for that raster layer. To do this, use either 
d.colors or r.colors, or you may manually edit the appropriate file (if 
the raster layer is in _your_ mapset, then the file would be 
$LOCATION/colr/raster_layer_name; if it is in someone else's mapset, the 
file would be $LOCATION/colr2/other_mapset_name/raster_layer_name. The 
colr2 directory allows you to have custom colortables for raster layers 
in other mapsets, without affecting the original.). I recommend 
copying the original colortable to a temporary filename, in case you want 
to revert to it. Because GRASS uses 24-bit color information, ps.map can 
actually print in TrueColor on an output device that supports it (like a 
dye-sublimation printer - we use an Apunix 24-bit printer, as well as an 
HP650c and a RasterGraphics 424CX color electrostatic plotter). Although 
the HP650c has to resort to dithering, it too can print much more than 
256 discernible colors.

We wrote a shell script to create a color "palette" in GRASS that has 729 
(9^3) colored boxes for a color reference plot; this is handy when 
choosing color values in GRASS for a particular printer. I would have to 
dig some, but I could probably find the files if you or anyone else 
would like them.

Lastly, the colortable command within ps.map is essentially a raster 
"legend" command; it simply prints a legend based on the colors in the 
raster layer. It will be affected by whatever changes you make to the 
GRASS colortable for that raster layer.

Hope this helps. Regards,
        -Malcolm Williamson

 On Fri, 7 Jul 1995, GREEN WILLIAM G 

> Hi folks,
> Sorry it took so long for me to respond, but I've been waiting for a message
> from someone who helped me set up my HP650c.  Here is her response:
> > Hi Bill,  The grass people themselves told me they did not write a device
> > driver for your type of HP plotter, nor did we.  This is actually quite a 
> > lot of work which is why you'd be so popular if you published one!  The 
> > solution was to run ps.map and save the output to a file.  From there you 
> > just print the file to the plotter with the lpr command.  The plotter 
> > understands postscript, so things print.   The problem you're having
> > (getting grass to specify different pen numbers) may relate to the
> > fact that there is no device driver.   It doesn't surprise me that p.chart
> > does not work since the Grass people told me the only print command that wi
> > work for you (since you have no device driver) is ps.map.  Perhaps there is
> > a way you can get ps.map to do what you need?  I don't think any of the 
> > other p.* programs will work either.  Sorry I can't be of more help.  Lesli
> > 
> Here is some other information that may help:
> 1) To get the HP650c to work, make a subdirectory called ps.devices under the
> paint directory.  Create a file in the paint subdirectory with the name of th
> postscript painter and the following information:
> level: 1 or 2 (it doesn't seem to matter)
> page width: 36
> page height: 54
> top margin: 0.5 (or whatever)
> bottom margin 0.5 (or whatever)
> left margin: 0.25 (or whatever)
> right margin: 0.25 (ditto)
> resolution: 300
> 2) The setcolor command in ps.map does not seem to work.  Also, I can't use
> a user-defined colortable because I can't print out the 125 colors that
> grass recognizes (that is the colortable command wants a value and I don't
> know what colors the values relate to).
> 3) Although the HP650c reference manual tells you to set the language to
> "automatic," this won't work.  You have to set the language to Postscript
> instead.
> 4) The add.pagesize isn't working correctly with the HP650c.  The command
> seems to work properly, but when I try to print the map out it disappears
> into the plotter's black hole (that is it receives the information but never
> prints anything out).  
> I hope this helps, but could someone answer my original question:  How do
> I control the raster color output since the setcolor command isn't working?
> Bill Green
> Archaeology Lab
> SUNY-Albany
> wg1938 at cnsunix.albany.edu

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