def distance(lat1, lon1, lat2, lon2):
"""
Compute the distance between a pair of lat/longs in meters using
the haversine calculation. The output distance is in meters.
Uses :func:`ichnaea._geocalc.distance` internally.
"""
return _geocalc.distance(lat1, lon1, lat2, lon2)
def _fill_bbox_cache():
cached = []
for country in countries:
iso2 = _best_guess_iso_2(country)
iso3 = _best_guess_iso_3(country)
if not (iso2 and iso3):
continue
(lon1, lat1, lon2, lat2) = country.bbox
radius = _geocalc.distance(lat1, lon1, lat2, lon2) / 2.0
cached.append(Subunit(bbox=country.bbox,
alpha2=iso2.upper(),
alpha3=iso3.upper(),
radius=int(radius)))
# sort by largest radius first
return list(sorted(cached, key=attrgetter('radius'), reverse=True))
