I am trying to calculate a distance between two points in Oracle DB,
Point A is 40.716715, -74.033907
Point B is 40.716300, -74.033900
using this sql statement:
SELECT sdo_geom.sdo_distance( sdo_geom.sdo_geometry(2001 ,8307 ,sdo_geom.sdo_point_type(40.716715, -74.033907 , NULL) ,NULL ,NULL)
,sdo_geom.sdo_geometry(2001 ,8307 ,sdo_point_type(40.716300,-74.033901, NULL) ,NULL ,NULL) ,0.0001 ,'unit=M') distance_in_m
from DUAL;
Result is 12.7646185977151
While doing it using Apple's CoreLocation api:
CLLocation* pa = [[CLLocation alloc] initWithLatitude:40.716715 longitude:-74.033907];
CLLocation* pa2 = [[CLLocation alloc] initWithLatitude:40.716300 longitude:-74.033900];
CLLocationDistance dist = [pa distanceFromLocation:pa2];
Result is 46.0888946842423
Own implementation
double dinstance_m(double lat1, double long1, double lat2, double long2){
double dlong = (long2 - long1) * d2r;
double dlat = (lat2 - lat1) * d2r;
double a = pow(sin(dlat/2.0), 2) + cos(lat1*d2r) * cos(lat2*d2r) * pow(sin(dlong/2.0), 2);
double c = 2 * atan2(sqrt(a), sqrt(1-a));
double d = 6367 * c;
return d * 1000.;
}
Result is 46.120690774231
Oracle's implementation is clearly off, but I don't see why. Any help would be greatly appreciated.
Try reversing the order of the ordinates, as in:
SELECT sdo_geom.sdo_distance(sdo_geom.sdo_geometry(2001, 8307, sdo_geom.sdo_point_type(-74.033907, 40.716715, NULL), NULL, NULL),
sdo_geom.sdo_geometry(2001, 8307, sdo_point_type(-74.033901, 40.716300, NULL), NULL, NULL), 0.0001, 'unit=M') distance_in_m
from DUAL;
I get 46.087817955912.
With SDO_GEOMETRY, ordinates are listed in X, Y (longitude, latitude) order.
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