예제 #1
0
// function computes distance between two non-null points
// function computes distance using Haversine formula
static double getDistance(const GeographyPointValue &point1,
                          const GeographyPointValue &point2)
{
    assert(!point1.isNull());
    assert(!point2.isNull());

    const S2LatLng latLng1 = S2LatLng(point1.toS2Point()).Normalized();
    const S2LatLng latLng2 = S2LatLng(point2.toS2Point()).Normalized();
    S1Angle distance = latLng1.GetDistance(latLng2);
    return distance.radians() * SPHERICAL_EARTH_MEAN_RADIUS_M;
}
예제 #2
0
template<> NValue NValue::call<FUNC_VOLT_DISTANCE_POINT_POINT>(const std::vector<NValue>& arguments) {
    assert(arguments[0].getValueType() == VALUE_TYPE_POINT);
    assert(arguments[1].getValueType() == VALUE_TYPE_POINT);

    if (arguments[0].isNull() || arguments[1].isNull()) {
        return NValue::getNullValue(VALUE_TYPE_DOUBLE);
    }

    // compute distance using Haversine formula
    // alternate to this is just obtain 2 s2points and compute S1Angle between them
    // and use that as distance.
    // S2 test uses S2LatLng for computing distances
    const S2LatLng latLng1 = S2LatLng(arguments[0].getGeographyPointValue().toS2Point()).Normalized();
    const S2LatLng latLng2 = S2LatLng(arguments[1].getGeographyPointValue().toS2Point()).Normalized();
    S1Angle distance = latLng1.GetDistance(latLng2);
    NValue retVal(VALUE_TYPE_DOUBLE);
    // distance is in radians, so convert it to meters
    retVal.getDouble() = distance.radians() * SPHERICAL_EARTH_MEAN_RADIUS_M;
    return retVal;
}