[GRASSLIST:1179] ps.map pixel size and line attributes

Roger S. Miller rgrmill at rt66.com
Fri Nov 24 16:00:00 EST 2000


I'm trying to construct an illustration that contains a large number of
lines (hydrologic features, roads and a rectangular grid for a ground
water model) overlain on a raster map showing results from the ground
water model.

Using ps.map from version 5, beta 7 I set the resolution of my postscript
device to 360 (supposedly, 360 dpi) and I specify that the vector files
should be plotted with a line width of 1 pixel.  The line I get is several
times wider than the 0.003 inch (approximate) thickness that it should be.
I need very fine lines on this map or the lines obscure each other and the
model results.

Is there some other way to reduce this pixel size?  I tried using
fractional pixel widths with no improvement.  I also tried using the
"cwidth" specification in ps.map.new and found that the lines in the model
grid vector file were not categorized, which brings up an entirely
different question.

I constructed the file with the model grid from an imported ascii file and
no attributes file was created when the file was imported.  I tried using
the bulk labeling option in v.digit to label the lines (there are over
13,000 lines, so manually labelling them would be inefficient at best),
but it doesn't work -- no errors are produced, but I get no labelled
lines.  Is there some other way to label the lines?  I program; if someone
can tell me how the lines are identified in the attribute files, then I
can construct the attribute file myself.

Roger Miller

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