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

Class DimensionSelectingLatLngDistanceFunction

java.lang.Object

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

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 DimensionSelectingLatLngDistanceFunction
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	DimensionSelectingLatLngDistanceFunction.Parameterizer Parameterization class.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	dimlat Latitude dimension.
(package private) int	dimlng Longitude dimension.
(package private) EarthModel	model Earth model used.

Constructor Summary

Constructors

Constructor and Description
DimensionSelectingLatLngDistanceFunction(int dimlat, int dimlng, 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

dimlat

final int dimlat

Latitude dimension.

dimlng

final int dimlng

Longitude dimension.

model

final EarthModel model

Earth model used.

Constructor Detail

DimensionSelectingLatLngDistanceFunction

public DimensionSelectingLatLngDistanceFunction(int dimlat,
                                                int dimlng,
                                                EarthModel model)

Constructor.

Parameters:

dimlat - Dimension storing the latitude

dimlng - Dimension storing the longitude

model - Earth model

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