Java Angle Calculate calculateAngle(int a1, int b1, int a2, int b2)

Description

Calculates the angle between two points in 2D space

License

Open Source License

Parameter

Parameter	Description
a1	a parameter
b1	a parameter
a2	a parameter
b2	a parameter

Declaration

public static double calculateAngle(int a1, int b1, int a2, int b2) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    /**/*from www  .j  av  a2 s.  c o  m*/
     * Calculates the angle between two points in 2D space
     * @param a1
     * @param b1
     * @param a2
     * @param b2
     * @return
     */
    public static double calculateAngle(int a1, int b1, int a2, int b2) {
        double distance_between_a1_a2 = calculateDifference(a1, a2);
        double distance_between_b1_b2 = calculateDifference(b1, b2);

        return Math.atan(distance_between_b1_b2 / distance_between_a1_a2);
    }

    /**
     * Calculates the angle between two points in 3D space
     * @param x1
     * @param y1
     * @param z1
     * @param x2
     * @param y2
     * @param z2
     * @return
     */
    public static double calculateAngle(int x1, int y1, int z1, int x2, int y2, int z2) {
        double distance_between_x1z1_x2z2 = calculateDistance(x1, z1, x2, z2);
        double distance_between_y1_y2 = calculateDifference(y1, y2);

        return Math.atan(distance_between_y1_y2 / distance_between_x1z1_x2z2);
    }

    /**
     * Calculates the absolute distance between two values
     * @param v1
     * @param v2
     * @return
     */
    public static double calculateDifference(int v1, int v2) {
        return v1 < v2 ? v2 - v1 : v1 - v2;
    }

    /**
     * This method calculated the distance between two points in 3D space
     * @param x1 X1
     * @param y1 Y1
     * @param z1 Z1
     * @param x2 X2
     * @param y2 Y2
     * @param z2 Z2
     * @return The distance between the two points
     */
    public static double calculateDistance(int x1, int y1, int z1, int x2, int y2, int z2) {
        double x_distance = x1 - x2;
        double y_distance = y1 - y2;
        double z_distance = z1 - z2;

        double sum = x_distance * x_distance;
        sum += y_distance * y_distance;
        sum += z_distance * z_distance;

        return Math.sqrt(sum);
    }

    /**
     * This method calculated the distance between two points in 3D space
     * @param a1
     * @param b1
     * @param a2
     * @param b2
     * @return
     */
    public static double calculateDistance(int a1, int b1, int a2, int b2) {
        double a_distance = a1 - a2;
        double b_distance = b1 - b2;

        double sum = a_distance * a_distance;
        sum += b_distance * b_distance;

        return Math.sqrt(sum);
    }
}

Related

1. angleOf(Point2D a, Point2D b)
2. anglePI(Point2D top, Point2D corner1, Point2D corner2)
3. angleToPoint(Rectangle r, double angle)
4. calculateAngle(double dx, double dy)
5. calculateAngle(float x, float y, float x1, float y1)