> is it possible to define start and end points with the attribut
> geographic coordinate, to display both in one map with the online
> service? Ideal would be to connect the two points.
There are two issues: how to represent the coordinates, and how to do
the map display.
1. In SMW 1.0, you can create an N-ary property "Start-end points" that
contains two geographic coordinates:
[[has type::Geographic coordinate;Geographic coordinate]]
This ties the two coordinates together. By default SMW displays the
subsequent properties in parenthesis, which is a little strange for your
use, see a test at http://ontoworld.org/wiki/Start-end_points_test
Or you could define two separate properties, Start_point and End_point,
both of Type:Geographic_coordinate. They'll be unrelated -- SMW won't
pair them up -- but if there is only one pair per article there's no
2. You can use service links to create a link to a map service. This
works for regular properties in 0.7, see
http://ontoworld.org/wiki/Help:Service_links. Depending on your mapping
service you could make Start_point green and End_point red.
I'm not sure how service links will work with N-ary properties. It
seems service links aren't currently working in SMW 1.0 RC1, as Markus
said on October 11th.
There are also extensions to the Semantic MediaWiki extension for
mapping; search the archives for "Semantic Layers" and "Semantic Google
If all else fails you could write your own datavalue handler that is
aware of start and end coordinates; it should be possible to reuse much
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