/// <inheritdoc />
public async Task <IEnumerable <LocationDto> > GetNearbyLocationsAsync(LocationDto location, int range,
int maxResults = 0)
{
var query = from dbLoc in _repository
let radiansLat1 = Math.PI * dbLoc.Latitude / 180
let radiansLat2 = Math.PI * location.Latitude / 180
let theta = dbLoc.Longitude - location.Longitude
let radiansTheta = Math.PI * theta / 180
let dist = Math.Acos(Math.Sin(radiansLat1) * Math.Sin(radiansLat2) +
Math.Cos(radiansLat1) * Math.Cos(radiansLat2) * Math.Cos(radiansTheta)) *
180 * 60 * 1.1515 * 1609.344 / Math.PI // Radius of the earth ~6371km
where dist <= range
orderby dist
select new LocationDto {
Latitude = dbLoc.Latitude,
Longitude = dbLoc.Longitude,
Address = dbLoc.Address,
Distance = dist
};
if (maxResults > 0)
{
query = query.Take(maxResults);
}
return(await query.ToListAsync());
}
/// <inheritdoc />
public async Task <IEnumerable <LocationDto> > GetNearbyLocationsAsync(LocationDto location, int range, int maxResults)
{
var point = _geometryFactory.CreatePoint(new Coordinate(location.Longitude, location.Latitude));
var query = from dbLoc in _repository
let distance = dbLoc.Coordinates.Distance(point)
where distance <= range
orderby distance
select new LocationDto {
Latitude = dbLoc.Coordinates.Y,
Longitude = dbLoc.Coordinates.X,
Distance = distance,
Address = dbLoc.Address
};
if (maxResults > 0)
{
query = query.Take(maxResults);
}
return(await query.ToListAsync());
}