Package elki.index.projected

Class LngLatAsECEFIndex<O extends NumberVector>

java.lang.Object

elki.index.projected.ProjectedIndex<O,O>

elki.index.projected.LngLatAsECEFIndex<O>

Type Parameters:

O - Object type

All Implemented Interfaces:

Index, KNNIndex<O>, RangeIndex<O>, RKNNIndex<O>

public class LngLatAsECEFIndex<O extends NumberVector>
extends ProjectedIndex<O,O>

Index a 2d data set (consisting of Lng/Lat pairs) by using a projection to 3D coordinates (WGS-86 to ECEF).

Earth-Centered, Earth-Fixed (ECEF) is a 3D coordinate system, sometimes also referred to as XYZ, that uses 3 cartesian axes. The center is at the earths center of mass, the z axis points to the north pole. X axis is to the prime meridan at the equator (so latitude 0, longitude 0), and the Y axis is orthogonal going to the east (latitude 0, longitude 90°E).

The Euclidean distance in this coordinate system is a lower bound for the great-circle distance, and Euclidean coordinates are supposedly easier to index.

Note: this index will only support the distance function LngLatDistance, as it uses a projection that will map data according to this great circle distance. If the query hint "exact" is set, it will not be used.

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LngLatAsECEFIndex.Factory<O extends NumberVector>	Index factory.

Nested classes/interfaces inherited from class elki.index.projected.ProjectedIndex

ProjectedIndex.ProjectedKNNByDBID, ProjectedIndex.ProjectedKNNByObject, ProjectedIndex.ProjectedRangeByDBID, ProjectedIndex.ProjectedRangeByObject, ProjectedIndex.ProjectedRKNNByDBID, ProjectedIndex.ProjectedRKNNByObject

Field Summary

Fields inherited from class elki.index.projected.ProjectedIndex

inner, kmulti, norefine, proj, refinements, relation, view

Constructor Summary

Constructors

Constructor	Description
LngLatAsECEFIndex(Relation<? extends O> relation, Projection<O,O> proj, Relation<O> view, Index inner, boolean norefine)	Constructor.

Method Summary

Modifier and Type	Method	Description
KNNSearcher<O>	kNNByObject(DistanceQuery<O> distanceQuery, int maxk, int flags)	Get a KNN query object for the given distance query and k.
RangeSearcher<O>	rangeByObject(DistanceQuery<O> distanceQuery, double maxradius, int flags)	Get a range query object for the given distance query and k.
RKNNSearcher<O>	rkNNByObject(DistanceQuery<O> distanceQuery, int maxk, int flags)	Get a RKNN query object for the given distance query and k.

Methods inherited from class elki.index.projected.ProjectedIndex

initialize, kNNByDBID, logStatistics, rangeByDBID, rkNNByDBID

Methods inherited from class java.lang.Object

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

Constructor Detail

LngLatAsECEFIndex

public LngLatAsECEFIndex(Relation<? extends O> relation,
                         Projection<O,O> proj,
                         Relation<O> view,
                         Index inner,
                         boolean norefine)

Constructor.

Parameters:

relation - Relation to index.

proj - Projection to use.

view - View to use.

inner - Index to wrap.

norefine - Refinement disable flag.

Method Detail

kNNByObject

public KNNSearcher<O> kNNByObject(DistanceQuery<O> distanceQuery,
                                  int maxk,
                                  int flags)

Description copied from interface: KNNIndex

Get a KNN query object for the given distance query and k.

This function MAY return null, when the given distance is not supported!

Specified by:

kNNByObject in interface KNNIndex<O extends NumberVector>

Overrides:

kNNByObject in class ProjectedIndex<O extends NumberVector,O extends NumberVector>

Parameters:

distanceQuery - Distance query

maxk - Maximum value of k

flags - Hints for the optimizer

Returns:

KNN Query object or null

rangeByObject

public RangeSearcher<O> rangeByObject(DistanceQuery<O> distanceQuery,
                                      double maxradius,
                                      int flags)

Description copied from interface: RangeIndex

Get a range query object for the given distance query and k.

This function MAY return null, when the given distance is not supported!

Specified by:

rangeByObject in interface RangeIndex<O extends NumberVector>

Overrides:

rangeByObject in class ProjectedIndex<O extends NumberVector,O extends NumberVector>

Parameters:

distanceQuery - Distance query

maxradius - Maximum range

flags - Hints for the optimizer

Returns:

KNN Query object or null

rkNNByObject

public RKNNSearcher<O> rkNNByObject(DistanceQuery<O> distanceQuery,
                                    int maxk,
                                    int flags)

Description copied from interface: RKNNIndex

Get a RKNN query object for the given distance query and k.

This function MAY return null, when the given distance is not supported!

Specified by:

rkNNByObject in interface RKNNIndex<O extends NumberVector>

Overrides:

rkNNByObject in class ProjectedIndex<O extends NumberVector,O extends NumberVector>

Parameters:

distanceQuery - Distance query

maxk - Maximum k for RkNN query

flags - Hints for the optimizer

Returns:

RKNN Query object or null