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

Class LatLngDistanceFunction

java.lang.Object

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

All Implemented Interfaces:

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

@Reference(authors="Erich Schubert, Arthur Zimek, Hans-Peter Kriegel",
           title="Geodetic Distance Queries on R-Trees for Indexing Geographic Data",
           booktitle="Int. Symp. Advances in Spatial and Temporal Databases (SSTD\'2013)",
           url="https://doi.org/10.1007/978-3-642-40235-7_9",
           bibkey="DBLP:conf/ssd/SchubertZK13")
public class LatLngDistanceFunction
extends java.lang.Object
implements SpatialPrimitiveDistanceFunction<NumberVector>, NumberVectorDistanceFunction<NumberVector>

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).

Reference:

Erich Schubert, Arthur Zimek, Hans-Peter Kriegel
Geodetic Distance Queries on R-Trees for Indexing Geographic Data
Int. Symp. Advances in Spatial and Temporal Databases (SSTD'2013)

Since:

0.4.0

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

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(java.lang.Object obj)
SimpleTypeInformation<? super NumberVector>	getInputTypeRestriction() Get the input data type of the function.
int	hashCode()
boolean	isMetric() Is this distance function metric (satisfy the triangle inequality)
double	minDist(SpatialComparable mbr1, SpatialComparable mbr2) Computes the distance between the two given MBRs according to this distance function.

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.SpatialPrimitiveDistanceFunction

instantiate

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

isSquared, 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>

Parameters:

o1 - first DatabaseObject

o2 - second DatabaseObject

Returns:

the distance between two given DatabaseObjects according to this distance function

minDist

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.

Specified by:

minDist in interface SpatialPrimitiveDistanceFunction<NumberVector>

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>

Returns:

Type restriction

isMetric

public boolean isMetric()

Description copied from interface: DistanceFunction

Is this distance function metric (satisfy the triangle inequality)

Specified by:

isMetric in interface DistanceFunction<NumberVector>

Returns:

true when metric.

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object