[OSM-talk] Converting buildings from nodes to ways

andrzej zaborowski balrogg at gmail.com
Thu Dec 23 16:06:32 GMT 2010


On 23 December 2010 13:10, Laurence Penney <lorp en lorp.org> wrote:
> I've been 'exploding' several building nodes into ways, based on splendid Bing imagery for Bristol. I'm getting concerned about data loss, the fact that any external database accumulating information on such vulnerable nodes, e.g. [1], will only with difficulty and guesswork be able to match it to the way that replaced it.
>
> I know the subject's been brought up several times before, but I'd to know the current state.
>
> * Is there a tagging convention to record node->way conversion, i.e. what was this way's predecessor_node?
> * If there is, has it been considered whether to allow JOSM to convert nodes to ways? e.g. a square, centred on the destroyed node, aligned to the grid, sized to 25% of the current window, prepopulated with the node's tags and a predecessor_node.

I think a tag or database attribute (this would obviously need to wait
for the next API version) like predecessor=<type:id>[;<type:id>[...]]
(e.g. node:84264734) would be useful.  It would be specially useful if
JOSM added it automatically to ways that are being split, merged etc.

There may be arguments that this would be just bloat for the database
but in fact it'd just be an improvement to the way history is kept
(without bearing on the advantages or disadvantages of keeping history
in general).

Cheers



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