[OSM-talk] Mapnik: strange prioritisation/appearance of place names

[David Earl]

On 23/03/2009 13:45, Adam Schreiber wrote:
>> Similarly, many US states have capitals which would otherwise be relatively
>> insignificant towns/cities (take Albany NY for example). Their
>> administrative function makes them more important than population alone
>> would suggest.
> 
> Albany would also no doubt have capital=yes set to further elevate it.


Precisely my point: population is not enough. There is a range of 
factors which any renderer or other data consumer would have to take 
into account. (capital is not for states but for nations BTW).

Consider a more obscure example. Walsingham in Norfolk, UK is a tiny 
village. However, it's importance is somewhat elevated over similar size 
neighbours because it is an internationally known centre of catholic 
pilgrimage. I would say, therefore, all other things being equal, if you 
could only display the names of one of the group of neighbouring 
villages, one should choose Walsingham. I don't think it is reasonable 
for the renderers to have to know about religious attractions (just an 
example, among many other possibilities) to be able to take this 
decision, so surely we have to have some kind of more generic way to 
express the importance.

One further point about population is that this data is not available 
for the UK - it is crown copyright. (I think settlement area would be a 
close correlate, at least within the same culture, so that might allow 
us to estimate it based on something we can measure ourselves).

David