给定纬度和经度，以及距离，我想找到一个边界框

Question

考虑到纬度和经度以及距离，我想找到一个距离小于给定距离的边界框。

此问题在此处提出：How to calculate the bounding box for a given lat/lng location?

我不希望这部分准确，所以我修改并简化为

def boundingBox(latitudeInDegrees, longitudeInDegrees, halfSideInKm):
    lat = math.radians(latitudeInDegrees)
    lon = math.radians(longitudeInDegrees)
    halfSide = 1000*halfSideInKm

    RADIUS_OF_EARTH  = 6371
    # Radius of the parallel at given latitude
    pradius = radius*math.cos(lat)

    latMin = lat - halfSide/radius
    latMax = lat + halfSide/radius
    lonMin = lon - halfSide/pradius
    lonMax = lon + halfSide/pradius
    rad2deg = math.degrees
    return (rad2deg(latMin), rad2deg(lonMin), rad2deg(latMax), rad2deg(lonMax))

但我无法理解这是如何运作的，特别是这条线对我没有意义halfSide = 1000*halfSideInKm

Answer 1

此代码不起作用，它在KM和M之间跳转。

固定代码，使名称更具PEP8风格，并添加了一个简单的框对象：

class BoundingBox(object):
    def __init__(self, *args, **kwargs):
        self.lat_min = None
        self.lon_min = None
        self.lat_max = None
        self.lon_max = None


def get_bounding_box(latitude_in_degrees, longitude_in_degrees, half_side_in_miles):
    assert half_side_in_miles > 0
    assert latitude_in_degrees >= -90.0 and latitude_in_degrees  <= 90.0
    assert longitude_in_degrees >= -180.0 and longitude_in_degrees <= 180.0

    half_side_in_km = half_side_in_miles * 1.609344
    lat = math.radians(latitude_in_degrees)
    lon = math.radians(longitude_in_degrees)

    radius  = 6371
    # Radius of the parallel at given latitude
    parallel_radius = radius*math.cos(lat)

    lat_min = lat - half_side_in_km/radius
    lat_max = lat + half_side_in_km/radius
    lon_min = lon - half_side_in_km/parallel_radius
    lon_max = lon + half_side_in_km/parallel_radius
    rad2deg = math.degrees

    box = BoundingBox()
    box.lat_min = rad2deg(lat_min)
    box.lon_min = rad2deg(lon_min)
    box.lat_max = rad2deg(lat_max)
    box.lon_max = rad2deg(lon_max)

    return (box)

Answer 2

该行正在将边界框单位从千米转换为米。