package ca.pfv.spmf.algorithms.clustering.distanceFunctions;
import ca.pfv.spmf.patterns.cluster.DoubleArray;
/* This file is copyright (c) 2008-2015 Philippe Fournier-Viger
*
* This file is part of the SPMF DATA MINING SOFTWARE
* (http://www.philippe-fournier-viger.com/spmf).
*
* SPMF is free software: you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later
* version.
*
* SPMF 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 General Public License for more details.
* You should have received a copy of the GNU General Public License along with
* SPMF. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* This class represent a distance function to calculate the distance between two
* arrays of double values. It is an abstract class having several subclasses
* such as the Euclidian distance and the Manathan distance.
* The distance classes are used by the clustering algorithm. It let the user
* choose which distance measure should be used.
* <br/><br/>
*
* @author Philippe Fournier-Viger
*/
public abstract class DistanceFunction {
/**
* Calculate the distance between two vectors of doubles.
* @param vector1 the first vector
* @param vector2 the second vector
* @return the distance
*/
public abstract double calculateDistance(DoubleArray vector1, DoubleArray vector2);
/**
* Get the nam of this distance function
* @return a string
*/
public abstract String getName();
/**
* This method returns the distance function having a given name
* @param name the name (euclidian, manathan, cosine, correlation,...)
* @return the distance function
*/
public static DistanceFunction getDistanceFunctionByName(String name){
if(DistanceCorrelation.NAME.equals(name)) {
return new DistanceCorrelation();
}else if(DistanceCosine.NAME.equals(name)) {
return new DistanceCosine();
}else if(DistanceEuclidian.NAME.equals(name)) {
return new DistanceEuclidian();
}else if(DistanceManathan.NAME.equals(name)) {
return new DistanceManathan();
}else if(DistanceJaccard.NAME.equals(name)) {
return new DistanceJaccard();
}
return null;
}
}