making efficient map layers

[Frank Warmerdam]

On Tue, 22 Mar 2005 10:06:55 -0500, Jeff Portwine <jdport at veritime.com> wrote:
> So, if I'm understanding correctly, a better way to do it would be to break
> the shapefiles down into individual road types and have a separate layer for
> each type... for example I could have an interstate shapefile, a state
> highway shapefile, a major roads shapefile, and a minor roads shapefile and
> make a separate layer for each of them.

Jeff,

Yes, I believe that would be an appropriate approach.  There are lots
of tools that could be used to accomplish this.  If I were doing it, I
would use ogr2ogr and it's -where argument to apply an attribute based
filter.

eg.

ogr2ogr out.shp in.shp -where CFCC=A13

You will presumably need to wrap this in appropriate scripts to
invoke it on each of your files in sequence.   You could also:
 o Write a python script using OGR to do something similar.
 o Use MapScript and use it's built in shapefile support, possibly
 o Use ArcGIS or ArcView (with appropriate scripts)
 o Use FME and do it with the visual modelling environment.
 o Load the data into PostGIS and use SQL to break things up.

... well, you get my point.  There are plenty of ways.

If you aren't handy with scripting this might be an onerous task.
I would suggest you *get handy* with scripting, or look into hiring
someone to help out on the data processing task.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent