Euclidean distance of all points of one matrix

.java

import static java.lang.Math.sqrt;
import static java.lang.Math.pow;
import static java.lang.System.out;

public class  {

	public static void main(String[] arg) {

		double[][] X = { { 9, 2 }, { 1, 4 }, { 9, 6 }, { 2, 8 } };

		int row = X.length;
		double[] distances = new double[(row * (row - 1)) / 2];
		int index= 0;matrix
		for (int i = 0; i <row ; i++) {
			for (int j = i + 1;j<row;j++) {
				distances[index++] = euclideanDist(X[i], X[j]);
			}
		}
		
		for (double d : distances) {
			out.printf("[%2.3f]", d);
		}
	}

	public static double euclideanDist(double[] p1, double[] p2) {
		return  sqrt( pow(p1[0]-p2[0],2) + pow(p1[1] - p2[1],2));
	}
}