Package org.apache.lucene.expressions.js

Class ExpressionMath

java.lang.Object

org.apache.lucene.expressions.js.ExpressionMath

public final class ExpressionMath
extends Object

Helper class holding static methods for js math functions

Method Summary

Modifier and Type	Method	Description
static double	haversinKilometers(double lat1, double lon1, double lat2, double lon2)	Returns the Haversine distance in kilometers between two points specified in decimal degrees (latitude/longitude).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

haversinKilometers

public static double haversinKilometers(double lat1,
                                        double lon1,
                                        double lat2,
                                        double lon2)

Returns the Haversine distance in kilometers between two points specified in decimal degrees (latitude/longitude). This works correctly even if the dateline is between the two points.

Error is at most 4E-1 (40cm) from the actual haversine distance, but is typically much smaller for reasonable distances: around 1E-5 (0.01mm) for distances less than 1000km.

Parameters:

lat1 - Latitude of the first point.

lon1 - Longitude of the first point.

lat2 - Latitude of the second point.

lon2 - Longitude of the second point.

Returns:

distance in kilometers.