de.lmu.ifi.dbs.elki.algorithm.outlier.spatial.neighborhood.weighted
Class LinearWeightedExtendedNeighborhood

java.lang.Object
  de.lmu.ifi.dbs.elki.algorithm.outlier.spatial.neighborhood.weighted.LinearWeightedExtendedNeighborhood

All Implemented Interfaces:

WeightedNeighborSetPredicate

public class LinearWeightedExtendedNeighborhood
extends Object
implements WeightedNeighborSetPredicate

Neighborhood obtained by computing the k-fold closure of an existing neighborhood. Objects are weighted linearly by their distance: the object itself has a weight of 1 and this decreases linearly to 1/(n+1) for the nth-step neighbors. TODO: make actual weighting parameterizable?

Nested Class Summary

static class

LinearWeightedExtendedNeighborhood.Factory<O> Factory class.

Field Summary

private NeighborSetPredicate	inner The data store to use
private int	steps The number of steps to extend to.

Constructor Summary

LinearWeightedExtendedNeighborhood(NeighborSetPredicate inner, int steps)
Constructor.

Method Summary

private double	computeWeight(int tsteps) Compute the weight from the number of steps needed.
Collection<DoubleObjPair<DBID>>	getWeightedNeighbors(DBID reference) Get the neighbors of a reference object for DBSCAN.

Methods inherited from class java.lang.Object

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

Field Detail

inner

private NeighborSetPredicate inner

The data store to use

steps

private int steps

The number of steps to extend to.

Constructor Detail

LinearWeightedExtendedNeighborhood

public LinearWeightedExtendedNeighborhood(NeighborSetPredicate inner,
                                          int steps)

Constructor.

Parameters:

inner - Inner neighborhood

steps - Number of steps to expand

Method Detail

computeWeight

private double computeWeight(int tsteps)

Compute the weight from the number of steps needed.

Parameters:

tsteps - steps to target

Returns:

weight

getWeightedNeighbors

public Collection<DoubleObjPair<DBID>> getWeightedNeighbors(DBID reference)

Description copied from interface: WeightedNeighborSetPredicate

Get the neighbors of a reference object for DBSCAN.

Specified by:

getWeightedNeighbors in interface WeightedNeighborSetPredicate

Parameters:

reference - Reference object

Returns:

Weighted Neighborhood