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lat/lng precision in geotree are not the same than in allCountries.txt  XML
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[Post New]23/09/2011 23:08:20
    Subject: lat/lng precision in geotree are not the same than in allCountries.txt
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sourcerh



Joined: 12/05/2010 19:37:38
Messages: 33
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Hello,

I can see in geotree, that Europe (http://geotree.geonames.org/?id=6255148) as the coordinates:
latitude = 48.690960390925
longitude = 9.140625

However, thanks to allCountries.txt (in allCountries.zip), the coordinates for Europe are:
latitude = 48.69096
longitude = 9.14062

=> as a result, geotree uses data that are more precise than the ones from allCountries.txt, is it an error from geotree or data from allCountries are rounded at 5 digits after the comma?

Thanks for your help

[Post New]25/09/2011 09:08:09
    Subject: Re:lat/lng precision in geotree are not the same than in allCountries.txt
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marc



Joined: 08/12/2005 07:39:47
Messages: 4501
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The coordinates are stored as float in the database. In the extract files they are cut to 5 decimal fractions. This is an accuracy of around 1m which is more than enough for the features included in the database. Nothing is gained with adding arbitrary digits after the comma in the extract files, they don't add any information or value.

Best Regards

Marc
[WWW]
[Post New]30/09/2011 07:01:37
    Subject: Re:lat/lng precision in geotree are not the same than in allCountries.txt
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sourcerh



Joined: 12/05/2010 19:37:38
Messages: 33
Offline
Ok perfect, thanks
 
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