似乎还没有一个好的Python 实现。幸运的是,“相关文章”侧边栏是我们的朋友。这篇文章 https://stackoverflow.com/questions/1689096/calculating-bounding-box-a-certain-distance-away-from-a-lat-long-coordinate-in-ja指向一个优秀的文章 http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates它给出了数学和 Java 实现。您需要的实际函数相当短,并且嵌入在下面我的 Python 代码中。已测试至所示程度。阅读评论中的警告。
from math import sin, cos, asin, sqrt, degrees, radians
Earth_radius_km = 6371.0
RADIUS = Earth_radius_km
def haversine(angle_radians):
return sin(angle_radians / 2.0) ** 2
def inverse_haversine(h):
return 2 * asin(sqrt(h)) # radians
def distance_between_points(lat1, lon1, lat2, lon2):
# all args are in degrees
# WARNING: loss of absolute precision when points are near-antipodal
lat1 = radians(lat1)
lat2 = radians(lat2)
dlat = lat2 - lat1
dlon = radians(lon2 - lon1)
h = haversine(dlat) + cos(lat1) * cos(lat2) * haversine(dlon)
return RADIUS * inverse_haversine(h)
def bounding_box(lat, lon, distance):
# Input and output lats/longs are in degrees.
# Distance arg must be in same units as RADIUS.
# Returns (dlat, dlon) such that
# no points outside lat +/- dlat or outside lon +/- dlon
# are <= "distance" from the (lat, lon) point.
# Derived from: http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates
# WARNING: problems if North/South Pole is in circle of interest
# WARNING: problems if longitude meridian +/-180 degrees intersects circle of interest
# See quoted article for how to detect and overcome the above problems.
# Note: the result is independent of the longitude of the central point, so the
# "lon" arg is not used.
dlat = distance / RADIUS
dlon = asin(sin(dlat) / cos(radians(lat)))
return degrees(dlat), degrees(dlon)
if __name__ == "__main__":
# Examples from Jan Matuschek's article
def test(lat, lon, dist):
print "test bounding box", lat, lon, dist
dlat, dlon = bounding_box(lat, lon, dist)
print "dlat, dlon degrees", dlat, dlon
print "lat min/max rads", map(radians, (lat - dlat, lat + dlat))
print "lon min/max rads", map(radians, (lon - dlon, lon + dlon))
print "liberty to eiffel"
print distance_between_points(40.6892, -74.0444, 48.8583, 2.2945) # about 5837 km
print
print "calc min/max lat/lon"
degs = map(degrees, (1.3963, -0.6981))
test(*degs, dist=1000)
print
degs = map(degrees, (1.3963, -0.6981, 1.4618, -1.6021))
print degs, "distance", distance_between_points(*degs) # 872 km