DoubleArrayEuclideanDistance.java

package fr.unistra.pelican.util.data.distances;

import fr.unistra.pelican.util.data.Data;

/**
 * euclidean distance to be computed between double arrays.
 * 
 * @author lefevre
 * 
 */
public class DoubleArrayEuclideanDistance extends EuclideanDistance {

	@Override
	public double distance( Data data1, Data data2 ) { 

		// Get the values of both data
		Double[] values  = ( Double[] ) data1.getValues();
		Double[] values2 = ( Double[] ) data2.getValues();

		// Check if both data have the same length
		double length = values.length;
		if ( length != values2.length ) return -1;

		// Compute the weighted euclidean distance
		double sum = 0;
		for ( int i = 0 ; i < length ; i++ )
			sum += Math.pow( values[i] - values2[i] , 2 );
		sum = Math.sqrt( sum );

		return sum;
	}

}