Pedro Roma wrote:
Hi guys
I've been reading Neteler/Mitasova book and I have a question:
Regarding vector data, what is a category?
A category specifies the category a vector feature belongs to, e.g.
highway, major road, minor road for lines or land cover type for areas.
See also
http://grass.osgeo.org/grass64/manuals/html64_user/vectorintro.html
and Why do I need to have category readers/writters?
In order to change categories of features.
Because, for What I understood, a category is like a Feature ID that
links a geometry to its attributes in a DB. Is this correct?
Yes. Also note that one feature can have several categories and several
features can share the same category. A link to attributes in a DB is
optional. An example for classified (categorized) vector features
without a db link is given in
http://grass.osgeo.org/grass64/manuals/html64_user/v.lidar.edgedetection.html
Markus M
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