de.lmu.ifi.dbs.elki.data.projection.random

Class AchlioptasRandomProjectionFamily

java.lang.Object

de.lmu.ifi.dbs.elki.data.projection.random.AbstractRandomProjectionFamily

de.lmu.ifi.dbs.elki.data.projection.random.AchlioptasRandomProjectionFamily

All Implemented Interfaces:

RandomProjectionFamily

@Reference(title="Database-friendly random projections: Johnson-Lindenstrauss with binary coins",
           authors="D. Achlioptas",
           booktitle="Proc. 20th ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems",
           url="https://doi.org/10.1145/375551.375608",
           bibkey="DBLP:conf/pods/Achlioptas01")
 @Alias(value="de.lmu.ifi.dbs.elki.math.linearalgebra.randomprojections.AchlioptasRandomProjectionFamily")
public class AchlioptasRandomProjectionFamily
extends AbstractRandomProjectionFamily

Random projections as suggested by Dimitris Achlioptas.

Reference:

D. Achlioptas
Database-friendly random projections: Johnson-Lindenstrauss with binary coins
Proc. 20th ACM SIGMOD-SIGACT-SIGART Symp. on Principles of database systems

TODO: faster implementation exploiting sparsity.

Since:

0.6.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AchlioptasRandomProjectionFamily.Parameterizer Parameterization class.

Nested classes/interfaces inherited from class de.lmu.ifi.dbs.elki.data.projection.random.AbstractRandomProjectionFamily

AbstractRandomProjectionFamily.MatrixProjection

Nested classes/interfaces inherited from interface de.lmu.ifi.dbs.elki.data.projection.random.RandomProjectionFamily

RandomProjectionFamily.Projection

Field Summary

Fields

Modifier and Type	Field and Description
private double	sparsity Projection sparsity.

Fields inherited from class de.lmu.ifi.dbs.elki.data.projection.random.AbstractRandomProjectionFamily

random

Constructor Summary

Constructors

Constructor and Description
AchlioptasRandomProjectionFamily(double sparsity, RandomFactory random) Constructor.

Method Summary

Modifier and Type	Method and Description
RandomProjectionFamily.Projection	generateProjection(int idim, int odim) Generate a projection matrix for the given dimensionalities.

Methods inherited from class java.lang.Object

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

Field Detail

sparsity

private double sparsity

Projection sparsity.

Constructor Detail

AchlioptasRandomProjectionFamily

public AchlioptasRandomProjectionFamily(double sparsity,
                                        RandomFactory random)

Constructor.

Parameters:

sparsity - Projection sparsity

random - Random number generator.

Method Detail

generateProjection

public RandomProjectionFamily.Projection generateProjection(int idim,
                                                            int odim)

Description copied from interface: RandomProjectionFamily

Generate a projection matrix for the given dimensionalities.

Parameters:

idim - Input Dimensionality

odim - Output Dimensionality

Returns:

Projection matrix