Java algorithm for calculating closest point

You need the distance formula

sqrt(a*a + b*b)

Check out my mathUtils class. I have distance already implemented

/*

* Created on Nov 7, 2004 by @author Tom Jacobs

*

*/

package tjacobs;

import java.awt.Point;

/**

* Simple math routines spelled out. There's euclideanDistance, factorial,

* combinations, distance.

*

* Pretty standard really.

*/

public class MathUtils {

private MathUtils() {

super();

}

public static double euclideanDistance(Point p1, Point p2) {

return Math.sqrt(Math.pow(p1.x - p2.x, 2) + Math.pow(p1.y - p2.y, 2));

}

public static int factorial(int x) {

int pow = 1;

while (x > 1) {

pow = pow * x;

x--;

}

return pow;

}

public static int getCombinations(int total, int picks, boolean replacing, boolean ordered) {

int ans = 0;

if (replacing && ordered) {

ans = (int)Math.pow(total, picks);

//total / Math.pow(totalpicks)

}

else if (!replacing && ordered){

ans = factorial (total);

ans /= factorial(total - picks);

} else if (replacing && !ordered) {

ans = factorial(total + picks - 1);

ans /= factorial(picks);

ans /= factorial(total - picks);

}

else if (!replacing && !ordered) {

ans = factorial(total);

ans/= factorial(picks);

ans/= factorial(total - picks);

}

return ans;

}

public static double distance (Point p1, Point p2) {

return distance(p1.x, p1.y, p2.x, p2.y);

}

public static double distance(double x1, double y1) {

return distance(x1, y1, 0, 0);

}

public static double distance (double x1, double y1, double x2, double y2) {

return Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));

}

public static double angle (Point p1, Point p2) {

return angle(p1.x, p1.y, p2.x, p2.y);

}

public static double angle (double x1, double y1, double x2, double y2) {

double xdiff = x1 - x2;

double ydiff = y1 - y2;

double tan = xdiff / ydiff;

double atan = Math.atan2(ydiff, xdiff);

return atan;

}

public static double reflectOff(double ray, double reflectOff) {

return reflectOff + reflectOff - ray;

}

//Testing only

/*public static void main(String args[]) {

System.out.println(reflectOff(0, Math.PI / 4) / Math.PI);

System.out.println(reflectOff(Math.PI / 2, Math.PI) / Math.PI);

System.out.println(reflectOff(5 * Math.PI / 4, Math.PI / 2) / Math.PI);

System.out.println(reflectOff(Math.PI, Math.PI / 2));

}

*/

}

tjacobs01a at 2007-7-10 3:47:51 >