距离排序

near.py

import math

from sqlalchemy import asc, func

from model.device.station import Station


def station_nearby_list(distance, longitude, latitude, page=None, limit=None):
    minlat, maxlat, minlng, maxlng = __get_area(latitude, longitude, distance)
    # 按距离最近排序
    order_by = asc(
        func.round(6371 * func.acos(
            func.cos(func.radians(Station.latitude))
            * func.cos(func.radians(latitude))
            * func.cos(func.radians(longitude) - func.radians(Station.longitude))
            + func.sin(func.radians(Station.latitude))
            * func.sin(func.radians(latitude))
        ))
    )
    station_nearby = Station.query.filter(Station.longitude.between(minlng, maxlng),
                                          Station.latitude.between(minlat, maxlat),
                                          Station.enable == bool(True),
                                          Station.is_deleted == bool(False),
                                          ).order_by(order_by)
    total = station_nearby.count() if station_nearby else 0
    if limit and page:
        offset = (int(page) - 1) * int(limit)
        station_nearby = station_nearby.offset(offset).limit(int(limit))
    result = [item.to_json() for item in station_nearby]
    return result, total


def pile_nearby_list(distance, longitude, latitude, page=None, limit=None):
    minlat, maxlat, minlng, maxlng = __get_area(latitude, longitude, distance)
    # 按距离最近排序
    order_by = asc(
        func.round(6371 * func.acos(
            func.cos(func.radians(Station.latitude))
            * func.cos(func.radians(latitude))
            * func.cos(func.radians(longitude) - func.radians(Station.longitude))
            + func.sin(func.radians(Station.latitude))
            * func.sin(func.radians(latitude))
        ))
    )
    station_nearby = Station.query.filter(Station.longitude.between(minlng, maxlng),
                                          Station.latitude.between(minlat, maxlat),
                                          Station.enable == bool(True),
                                          Station.is_deleted == bool(False),
                                          ).order_by(order_by)
    total = station_nearby.count() if station_nearby else 0
    if limit and page:
        offset = (int(page) - 1) * int(limit)
        station_nearby = station_nearby.offset(offset).limit(int(limit))
    result = [item.to_json() for item in station_nearby]
    return result, total


def __get_area(latitude, longitude, dis):
    """
    确定查询经纬度范围
    :param latitude:中心纬度
    :param longitude:中心经度
    :param dis:半径
    :return:(minlat, maxlat, minlng, maxlng)
    """
    r = 6371.137
    dlng = 2 * math.asin(math.sin(dis / (2 * r)) / math.cos(latitude * math.pi / 180))
    dlng = dlng * 180 / math.pi
    dlat = dis / r
    dlat = dlat * 180 / math.pi
    minlat = latitude - dlat
    maxlat = latitude + dlat
    minlng = longitude - dlng
    maxlng = longitude + dlng
    return minlat, maxlat, minlng, maxlng


def cal_dis(longitude1: float, latitude1: float, longitude2: float, latitude2: float):
    """
    根据经纬度计算距离
    :param longitude1: 经度1
    :param latitude1: 纬度1
    :param longitude2: 经度2
    :param latitude2: 纬度2
    :return: 返回为km单位 保留两位小数
    """
    latitude1 = (math.pi / 180.0) * latitude1
    latitude2 = (math.pi / 180.0) * latitude2
    longitude1 = (math.pi / 180.0) * longitude1
    longitude2 = (math.pi / 180.0) * longitude2
    # 因此AB两点的球面距离为:{arccos[sina*sinx+cosb*cosx*cos(b-y)]}*R  (a,b,x,y)
    # 地球半径
    R = 6378.1
    temp = math.sin(latitude1) * math.sin(latitude2) + \
           math.cos(latitude1) * math.cos(latitude2) * math.cos(longitude2 - longitude1)
    if float(repr(temp)) > 1.0:
        temp = 1.0
    d = math.acos(temp) * R
    return round(d, 2);


if __name__ == '__main__':
    # result, total = station_nearby_list(distance=4, latitude=28.6712732625, longitude=115.8807849884)
    print(cal_dis(longitude1=115.860788, latitude1=28.698319, longitude2=115.859198, latitude2=28.682587))