Hello,
I’m creating a mapping application using 2008 census tiger shapefiles. I would like to create a map that looks like:
http://sigma.openplans.org/
I was looking on
http://geoserver.org/display/GEOSDOC/Google+Maps+SLD
in how to do so.
The tutorial mentions
“but I wanted to build something more general that could be used for (mostly) out of the box Tiger data”.
The SLD’s that the tutorial has attached do not work with the 2008 shapefiles. They reference shapefiles properties like:
gen_full
statehighway
gen_1
ushighway
The 2008 shapefiles do not have these properties. The only way to know that a certain feature is a state or us highway is by looking at the mtfcc code. Are these simply very old SLD’s that were made for the old line format? Does anyone know or have any shapefiles that were created for the 2008 census shapefiles? I’d like to use those as reference to create my own if possible.
Thanks
–
Signed,
Alessandro Ferrucci
Alessandro Ferrucci ha scritto:
Hello,
I'm creating a mapping application using 2008 census tiger shapefiles. I would like to create a map that looks like:
http://sigma.openplans.org/
I was looking on
http://geoserver.org/display/GEOSDOC/Google+Maps+SLD
in how to do so.
The tutorial mentions
"but I wanted to build something more general that could be used for (mostly) out of the box Tiger data".
The SLD's that the tutorial has attached do not work with the 2008 shapefiles. They reference shapefiles properties like:
gen_full
statehighway
gen_1
ushighway
The 2008 shapefiles do not have these properties. The only way to know that a certain feature is a state or us highway is by looking at the mtfcc code. Are these simply very old SLD's that were made for the old line format? Does anyone know or have any shapefiles that were created for the 2008 census shapefiles? I'd like to use those as reference to create my own if possible.
The SLD assumed data that was customized for performance, in particular:
- the geometries were duplicated and generalized at different levels
so that not too much data was loaded when zoomed out, and the
SLD was used to choose the appropriate geometry given the current
zoom level. gen_full was the native geometry, then there were other
columns with more and more simplified versions of the same geometry
- columns like statehighway and ushighway seem like preprocessed fiters,
instead of hitting the database with longer, less efficient queries
like "ATT = 'AB' or ATT = 'BC' or ..." the classification was done
just once and those attributes where boolean marking if a feature
was a state highway or a national highway and so on (not fully sure
about this, I was not involved in the sigma setup back then, but
it would seem the most sensible explanation)
Hope this helps
Cheers
Andrea
--
Andrea Aime
OpenGeo - http://opengeo.org
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