[OSM-dev] Binary OSM; the first pass encoder

[Robert (Jamie) Munro]

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Stefan de Konink wrote:
> At #osm-nl we ar discussing the float -> long thing. I used floats 
> because it (obviously) allows more precision, but I agree on some points 
> mentioned before.

Floats only allow more precision as the location being considered tends
towards 0,0 latitude and longitude. For the general case, using an
integer with the same number of bits of storage will always be more
precise, particularly at the extremes.

As others have said, 32 bits gives errors of less than 10mm on the
equator, with even greater accuracy as you move away from it. This is
around 1000 times more accurate than the data in OSM can be reasonably
recorded at with standard GPS equipment.

Robert (Jamie) Munro
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