python实现两个经纬度点之间的距离和方位角

from：http://blog.csdn.net/zhuqiuhui/article/details/53180395

1.  求两个经纬点的方位角，P0(latA, lonA), P1(latB, lonB)（很多博客写的不是很好，这里总结一下）

    def getDegree(latA, lonA, latB, lonB):
        """
        Args:
            point p1(latA, lonA)
            point p2(latB, lonB)
        Returns:
            bearing between the two GPS points,
            default: the basis of heading direction is north
        """
        radLatA = radians(latA)
        radLonA = radians(lonA)
        radLatB = radians(latB)
        radLonB = radians(lonB)
        dLon = radLonB - radLonA
        y = sin(dLon) * cos(radLatB)
        x = cos(radLatA) * sin(radLatB) - sin(radLatA) * cos(radLatB) * cos(dLon)
        brng = degrees(atan2(y, x))
        brng = (brng + 360) % 360
        return brng

2.  求两个经纬点的距离函数：P0(latA, lonA), P1(latB, lonB)

def haversine(a, b): # 经度1，纬度1，经度2，纬度2 （十进制度数）
    """
    Calculate the great circle distance between two points
    on the earth (specified in decimal degrees)
    """
    lat1 = a[0][0]
    lon1 = a[1][0]
    lat2 = b[0][0]
    lon2 = b[1][0]
 
    # 将十进制度数转化为弧度
    lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])  
 
    # haversine公式
    dlon = lon2 - lon1
    dlat = lat2 - lat1
    a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
    c = 2 * asin(sqrt(a))
    r = 6371 # 地球平均半径，单位为公里
    return c * r * 1000