org.apache.mahout.math.neighborhood

Class ProjectionSearch

java.lang.Object

org.apache.mahout.math.neighborhood.Searcher

org.apache.mahout.math.neighborhood.UpdatableSearcher

org.apache.mahout.math.neighborhood.ProjectionSearch

All Implemented Interfaces:

Iterable<Vector>

public class ProjectionSearch
extends UpdatableSearcher

Does approximate nearest neighbor dudes search by projecting the data.

Field Summary

Fields inherited from class org.apache.mahout.math.neighborhood.Searcher

distanceMeasure

Constructor Summary

Constructors

Constructor and Description
ProjectionSearch(DistanceMeasure distanceMeasure, int numProjections, int searchSize)

Method Summary

Modifier and Type	Method and Description
void	add(Vector vector) Adds a WeightedVector into the set of projections for later searching.
void	clear()
Iterator<Vector>	iterator()
boolean	remove(Vector vector, double epsilon)
List<WeightedThing<Vector>>	search(Vector query, int limit) Searches for the query vector returning the closest limit referenceVectors.
WeightedThing<Vector>	searchFirst(Vector query, boolean differentThanQuery) Returns the closest vector to the query.
int	size() Returns the number of scalarProjections that we can search

Methods inherited from class org.apache.mahout.math.neighborhood.Searcher

addAll, addAllMatrixSlices, addAllMatrixSlicesAsWeightedVectors, getCandidateQueue, getDistanceMeasure, search, searchFirst

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

ProjectionSearch

public ProjectionSearch(DistanceMeasure distanceMeasure,
                        int numProjections,
                        int searchSize)

Method Detail

add

public void add(Vector vector)

Adds a WeightedVector into the set of projections for later searching.

Specified by:

add in class Searcher

Parameters:

vector - The WeightedVector to add.

size

public int size()

Returns the number of scalarProjections that we can search

Specified by:

size in class Searcher

Returns:

The number of scalarProjections added to the search so far.

search

public List<WeightedThing<Vector>> search(Vector query,
                                          int limit)

Searches for the query vector returning the closest limit referenceVectors.

Specified by:

search in class Searcher

Parameters:

query - the vector to search for.

limit - the number of results to return.

Returns:

a list of Vectors wrapped in WeightedThings where the "thing"'s weight is the distance.

searchFirst

public WeightedThing<Vector> searchFirst(Vector query,
                                         boolean differentThanQuery)

Returns the closest vector to the query. When only one the nearest vector is needed, use this method, NOT search(query, limit) because it's faster (less overhead).

Specified by:

searchFirst in class Searcher

Parameters:

query - the vector to search for

differentThanQuery - if true, returns the closest vector different than the query (this only matters if the query is among the searched vectors), otherwise, returns the closest vector to the query (even the same vector).

Returns:

the weighted vector closest to the query

iterator

public Iterator<Vector> iterator()

remove

public boolean remove(Vector vector,
                      double epsilon)

Specified by:

remove in class UpdatableSearcher

clear

public void clear()

Specified by:

clear in class UpdatableSearcher