[OSM-dev] [OSM-talk] New Export Tab

Patrick Weber p.weber at ucl.ac.uk
Mon Apr 21 11:05:29 BST 2008


The problem with Shapefile support is that the datamodel of OSM is not 
very well suited for direct translation into Shapefiles. there are 
several issues:

A shapefile only supports one  feature type. So  one export would need 
to have at least two (ideally 3) shapefiles for points, lines, areas. 
Areas (polygons) are also only defined through the tagging scheme, so 
any converter will need to be constantly updated from the wiki page to 
correctly identify and convert lines to areas.

The data schema with its multiple tag value pairs as well poses some 
problems. The shapefile will need to include columns for all tags 
included in the export. This impacts negatively performance importing 
and processing shapefiles. Also, multiple values for the same tags pose 
a problem in such a scenario.

I have personally developed a import script for OSM XML data (obtained 
from the API) for the Manifold GIS software. My workaround for the 
performance issue with multiple columns was to only retain the OSMID in 
the actual Geometry layer, and save all tagging data in a separate table 
as OSMID, tag, value triplets. One can then join back relevant tags as 
needed.

I dont know about the data structure of KML or GML. as these are XML as 
well though they might prove easier?


Iván Sánchez Ortega wrote:
> <quote who="Axel von Matern">
>   
>> - Is it possible to import the XML-file into Illustrator?
>>     
>
> Related question:
>
> Would it be possible/easy to export a shapefile, or GML, or KML, or any
> other professional-looking format?
>
>
>   
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