import java.lang.Math._
import com.github.davidmoten.rtree.geometry.{Point, Rectangle}
import com.github.davidmoten.rtree.geometry.Geometries._
def distance(p1: Point, p2: Point): Double = {
val radLon1 = toRadians(p1.x)
val radLat1 = toRadians(p1.y)
val radLon2 = toRadians(p2.x)
val radLat2 = toRadians(p2.y)
val x = sin((radLon2 - radLon1) * 0.5)
val y = sin((radLat2 - radLat1) * 0.5)
val a = y * y + cos(radLat1) * cos(radLat2) * x * x
atan2(sqrt(a), sqrt(1 - a)) * 12756274 // The Earth diameter in meters
}
计算边界框，请使用以下函数：
def boundingRectangles(c: Point, r: Double): List[Rectangle] = {
val radLon = toRadians(c.x)
val radLat = toRadians(c.y)
val radDist = r / 6378137 // The Earth radius in meters
val lat1 = toDegrees(radLat - radDist)
val lat2 = toDegrees(radLat + radDist)
if (lat1 > -90 && lat2 < 90) {
val deltaLon = asin(sin(radDist) / cos(radLat))
val lon1 = toDegrees(radLon - deltaLon)
val lon2 = toDegrees(radLon + deltaLon)
if (lon1 < -180) rectangle(-180, lat1, lon2, lat2) :: rectangle(lon1 + 360, lat1, 180, lat2) :: Nil
else if (lon2 > 180) rectangle(-180, lat1, lon2 - 360, lat2) :: rectangle(lon1, lat1, 180, lat2) :: Nil
else rectangle(lon1, lat1, lon2, lat2) :: Nil
} else rectangle(-180, max(lat1, -90), 180, min(lat2, 90)) :: Nil
}