CODEWITHSUNDEEP
javaarraysvectoreuclidean-distance
dcrearer
dcrearer

Reputation: 2072

Euclidean Distance between 2 Vectors Implementation

I working through a few exercises from an academic programing book. The task is to implement 2 vectors and calculate the Euclidean distance between thereof. No this is not Home Work, rather self studying.

I'm seeking some feedback on the correctness of my distance implementation.

public class EuclideanDist
{
    public static void main(String[] args)
    {   
        EuclideanDist euc = new EuclideanDist();
        Random rnd = new Random();        

        int N = Integer.parseInt(args[0]);

        double[] a = new double[N];
        double[] b = new double[N];
        double[] x = new double[N];

        euc.print(euc.init(a, rnd));        
        euc.print(euc.init(b, rnd));        
        print(euc.distance(a, b, x));
    }

    private double[] init(double[] src, Random rnd)
    {
        for(int i = 0; i < src.length; i++)
        {
            src[i] = rnd.nextDouble();
        }
        return src;
    }
    private double[] distance(double[] a, double[] b, double[] x)
    {
        double diff; 
        int N = a.length;

        for(int i = 0; i < N; i++)
        {
            diff = a[i] - b[i];
            x[i] = Math.sqrt(diff * diff);
        }
        return x;
    }
    private static void print(double[] x)
    {
        int N = x.length;
        for(int j = 0; j < N; j++)
            System.out.print(" " + x[j] + " ");
        System.out.println();
    }
}

Upvotes: 0

Views: 10981

Answers (1)

Tsung-Ting Kuo
Tsung-Ting Kuo

Reputation: 1170

Based on the suggestions of @AlanStokes, the following codes seems to be one solution (I have tested it):

import java.util.Random;

public class EuclideanDist {
    public static void main(String[] args) {
        EuclideanDist euc = new EuclideanDist();
        Random rnd = new Random();

        int N = Integer.parseInt(args[0]);

        double[] a = new double[N];
        double[] b = new double[N];

        euc.print(euc.init(a, rnd));
        euc.print(euc.init(b, rnd));
        System.out.println(euc.distance(a, b));
    }

    private double[] init(double[] src, Random rnd) {
        for (int i = 0; i < src.length; i++) {
            src[i] = rnd.nextDouble();
        }
        return src;
    }

    private double distance(double[] a, double[] b) {
        double diff_square_sum = 0.0;
        for (int i = 0; i < a.length; i++) {
            diff_square_sum += (a[i] - b[i]) * (a[i] - b[i]);
        }
        return Math.sqrt(diff_square_sum);
    }

    private void print(double[] x) {
        for (int j = 0; j < x.length; j++) {
            System.out.print(" " + x[j] + " ");
        }
        System.out.println();
    }
}

Upvotes: 4

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