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datasets / geo-countries

Country polygons as GeoJSON in a datapackage
https://datahub.io/core/geo-countries
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Resolution #4

Open letmaik opened 8 years ago

letmaik commented 8 years ago

Which resolution is this dataset in? Also, since https://github.com/datasets/geo-boundaries-world-110m redirects to this repo I expected to find a 110m version here. This would be useful for many web applications.

lexman commented 8 years ago

Hello,

the resolution is 10 m. It has been changed from the original you mention because the 110m source data from Natural Earth didn't include all the countries (https://github.com/datasets/geo-countries/issues/1).

Is the current datapackage usable for a web application ?

letmaik commented 8 years ago

I see. The file is 23MB which is typically too big for a web application, so depending on the use case you would have to downsample that (polygon simplification + reducing coordinate precision + minifying the JSON), restrict it to certain countries, or serve it as vector tiles. Still, for simple use cases it would be nice to have a low-resolution version which you can just put on a web server and load directly, like the 110m one.

ck-jrd commented 6 years ago

Correct me if I'm wrong, but this dataset is in muuuuuuch finer than 10m resolution. With lat/long coordinates at 15 decimal places, we're getting into the fractions-of-a-nanometer resolution.

4 decimal places is precise to 11m 5 decimal places is 1.1m 6 is 11cm 7 is 1.1cm ... 15 is 0.0000011 mm.

My question is, why is this dataset so unnecessarily precise? The filesize of the dataset could be reduced by nearly half if the coordinates were trimmed to 6 decimal places.