On Thu, 10 Dec 2009 21:40:39 -0500, Frank Steggink <stegg...@steggink.org> wrote: > Hi, > > I've created a small Python tool which buffers the polygon in a polygon > file (for Osmosis),
Excuse me, wich polygon is buffered, when and for what purpose? >From the source I see "Calculate a buffer around the polygon, using PostGIS". So this creates some PostGIS geometry that covers whatever the polygon covers "NB: holes aren't supported yet" plus some area around the polygon? Then this (temporary?) geometry is exported as another polygon-file? If is is a python-scrips, how is it used with Osmosis? I guess these created polygon-files are nice for extracts that shall contain elements next to the border? Why does it need a PostGIS for this job? Wouldn't calculating the normal in each vertex and offsetting the vertex along that normal be enough? (Plus a check if the new location is not inside the polygon, else offset only to the point where it touches the polygon.) > and creates a new polygon file. It can be found > here: [1]. For the buffering PostGIS is used. All Canadian polygon files > from [2] have been tested and are working. > > Requirements: Python (2.6, but 2.5 likely works too), PostGIS (1.3+), > PyGreSQL > More info can be found in the file itself, or by typing "./polybuffer.py > -h" in the command prompt. > > Please let me know any issues you experience with this tool. > > Cheers, > > Frank > > [1] > http://svn.openstreetmap.org/applications/utils/osm-extract/polygons/polybuffer.py > [2] http://www.maproom.psu.edu/dcw/ Regards, Marcus _______________________________________________ dev mailing list dev@openstreetmap.org http://lists.openstreetmap.org/listinfo/dev
