de.lmu.ifi.dbs.elki.distance.distancefunction.geo

Class LatLngDistanceFunction

java.lang.Object

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractPrimitiveDistanceFunction<NumberVector>

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractNumberVectorDistanceFunction

de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialDistanceFunction

de.lmu.ifi.dbs.elki.distance.distancefunction.geo.LatLngDistanceFunction

All Implemented Interfaces:

DistanceFunction<NumberVector>, NumberVectorDistanceFunction<NumberVector>, PrimitiveDistanceFunction<NumberVector>, SpatialPrimitiveDistanceFunction<NumberVector>

public class LatLngDistanceFunction
extends AbstractSpatialDistanceFunction

Distance function for 2D vectors in Latitude, Longitude form. The input data must be in degrees (not radians), and the output distance will be in meters (see EarthModel.distanceDeg(double, double, double, double)). This implementation allows index accelerated queries using R*-trees (by providing a point-to-rectangle minimum distance), as published in:

Erich Schubert, Arthur Zimek and Hans-Peter Kriegel
Geodetic Distance Queries on R-Trees for Indexing Geographic Data
Advances in Spatial and Temporal Databases - 13th International Symposium, SSTD 2013, Munich, Germany

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LatLngDistanceFunction.Parameterizer Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
private EarthModel	model Earth model to use.

Constructor Summary

Constructors

Constructor and Description
LatLngDistanceFunction(EarthModel model) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
double	distance(NumberVector o1, NumberVector o2) Computes the distance between two given DatabaseObjects according to this distance function.
boolean	equals(Object obj)
SimpleTypeInformation<? super NumberVector>	getInputTypeRestriction() Get the input data type of the function.
int	hashCode()
double	minDist(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the two given MBRs according to this distance function.

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialDistanceFunction

instantiate

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractNumberVectorDistanceFunction

dimensionality, dimensionality, dimensionality, dimensionality

Methods inherited from class de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractPrimitiveDistanceFunction

isMetric, isSymmetric

Methods inherited from class java.lang.Object

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

Methods inherited from interface de.lmu.ifi.dbs.elki.distance.distancefunction.DistanceFunction

isMetric, isSymmetric

Field Detail

model

private EarthModel model

Earth model to use.

Constructor Detail

LatLngDistanceFunction

public LatLngDistanceFunction(EarthModel model)

Constructor.

Method Detail

distance

public double distance(NumberVector o1,
              NumberVector o2)

Description copied from interface: PrimitiveDistanceFunction

Computes the distance between two given DatabaseObjects according to this distance function.

Specified by:

distance in interface NumberVectorDistanceFunction<NumberVector>

Specified by:

distance in interface PrimitiveDistanceFunction<NumberVector>

Specified by:

distance in class AbstractPrimitiveDistanceFunction<NumberVector>

Parameters:

o1 - first DatabaseObject

o2 - second DatabaseObject

Returns:

the distance between two given DatabaseObjects according to this distance function

minDist

@Reference(authors="Erich Schubert, Arthur Zimek and Hans-Peter Kriegel",
           title="Geodetic Distance Queries on R-Trees for Indexing Geographic Data",
           booktitle="Advances in Spatial and Temporal Databases - 13th International Symposium, SSTD 2013, Munich, Germany")
public double minDist(SpatialComparable mbr1,
                                            SpatialComparable mbr2)

Description copied from interface: SpatialPrimitiveDistanceFunction

Computes the distance between the two given MBRs according to this distance function.

Parameters:

mbr1 - the first MBR object

mbr2 - the second MBR object

Returns:

the distance between the two given MBRs according to this distance function

getInputTypeRestriction

public SimpleTypeInformation<? super NumberVector> getInputTypeRestriction()

Description copied from interface: DistanceFunction

Get the input data type of the function.

Specified by:

getInputTypeRestriction in interface DistanceFunction<NumberVector>

Specified by:

getInputTypeRestriction in interface PrimitiveDistanceFunction<NumberVector>

Overrides:

getInputTypeRestriction in class AbstractNumberVectorDistanceFunction

Returns:

Type restriction

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object