package de.lmu.ifi.dbs.elki.data.projection;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2013
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
ELKI Development Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see .
*/
import de.lmu.ifi.dbs.elki.data.NumberVector;
import de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation;
import de.lmu.ifi.dbs.elki.data.type.TypeInformation;
import de.lmu.ifi.dbs.elki.data.type.TypeUtil;
import de.lmu.ifi.dbs.elki.data.type.VectorFieldTypeInformation;
import de.lmu.ifi.dbs.elki.logging.Logging;
import de.lmu.ifi.dbs.elki.math.linearalgebra.randomprojections.AchlioptasRandomProjectionFamily;
import de.lmu.ifi.dbs.elki.math.linearalgebra.randomprojections.RandomProjectionFamily;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.constraints.CommonConstraints;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.IntParameter;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectParameter;
/**
* Randomized projections of the data.
*
* This class allows projecting the data with different types of random
* projections, in particular database friendly projections (as suggested by
* Achlioptas, see {@link AchlioptasRandomProjectionFamily}), but also as
* suggested for locality sensitive hashing (LSH).
*
* @author Erich Schubert
*
* @param Vector type
*/
public class RandomProjection> implements Projection {
/**
* Class logger.
*/
private static final Logging LOG = Logging.getLogger(RandomProjection.class);
/**
* Vector factory.
*/
private NumberVector.Factory factory = null;
/**
* Output dimensionality.
*/
private int dimensionality;
/**
* Projection matrix.
*/
private RandomProjectionFamily.Projection projection = null;
/**
* Random projection family
*/
private RandomProjectionFamily family;
/**
* Constructor.
*
* @param dimensionality Desired dimensionality
* @param family Random projection family
*/
public RandomProjection(int dimensionality, RandomProjectionFamily family) {
super();
this.dimensionality = dimensionality;
this.family = family;
}
@Override
public void initialize(SimpleTypeInformation in) {
final VectorFieldTypeInformation vin = (VectorFieldTypeInformation) in;
factory = (NumberVector.Factory) vin.getFactory();
int inputdim = vin.getDimensionality();
projection = family.generateProjection(inputdim, dimensionality);
if(LOG.isDebugging()) {
LOG.debug(projection.toString());
}
}
@Override
public V project(V data) {
return factory.newNumberVector(projection.project(data));
}
@Override
public TypeInformation getInputDataTypeInformation() {
return TypeUtil.NUMBER_VECTOR_FIELD;
}
@Override
public SimpleTypeInformation getOutputDataTypeInformation() {
return new VectorFieldTypeInformation<>(factory, dimensionality);
}
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static class Parameterizer extends AbstractParameterizer {
/**
* Parameter for the projection family.
*/
public static final OptionID FAMILY_ID = new OptionID("randomproj.family", "Projection family to use.");
/**
* Parameter for the desired output dimensionality.
*/
public static final OptionID DIMENSIONALITY_ID = new OptionID("randomproj.dimensionality", "Amount of dimensions to project to.");
/**
* Output dimensionality.
*/
private int dimensionality;
/**
* Random generator.
*/
private RandomProjectionFamily family;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
ObjectParameter familyP = new ObjectParameter<>(FAMILY_ID, RandomProjectionFamily.class);
familyP.setDefaultValue(AchlioptasRandomProjectionFamily.class);
if(config.grab(familyP)) {
family = familyP.instantiateClass(config);
}
IntParameter dimP = new IntParameter(DIMENSIONALITY_ID);
dimP.addConstraint(CommonConstraints.GREATER_EQUAL_ONE_INT);
if(config.grab(dimP)) {
dimensionality = dimP.intValue();
}
}
@Override
protected RandomProjection> makeInstance() {
return new RandomProjection<>(dimensionality, family);
}
}
}