I believe my earlier questions have not been very well phrased. Here is
my situation: I have an ongoing need to make a variety of maps of more
or less the same kind. I have a small area, divided into 39 towns and
about 75 zip code areas, for which I already have a dandy set of
ESRI-style shapefiles. I have some data by town, and some data by the
zips. No doubt I'll someday get data in some other package, too, like
legislative districts or counties.
The maps I want to make are pretty simple: color this town red if value
X is over 12, and green if it's under. Color the town yellow if Y is
also greater than 6. When I get data in the zip code areas, I'll need
to re-jigger it into the towns somehow, so it can be compared with the
other town data.
This is a long-term thing, and I don't mind putting in the time to learn
a new package. I'm not looking for quick-and-dirty solutions. But I am
apparently very confused about what software is for which part of my
tasks. I thought these were GIS tasks, and that QGIS was a GIS system,
so it could do that, QED. (And the manuals I've read have been ambiguos
enough that I couldn't resolve these questions there.)
This is apparently not a QGIS thing. Is it a QGIS/GRASS set of tasks?
Is there a way to run GRASS without QGIS, or am I supposed to think of
GRASS as an extension to QGIS?
Is some part of this best done with PostGIS? If so, which part, and
do I use QGIS as the PostGIS client, or is there a better PostGIS
client I should learn?
Can I get print-quality (postscript is best) output from any of these
systems, or does this requirement create restrictions I should know
about now before I invest the time?