[Solved] How to calculate shortest distance from path?

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  1. Mathematically :

    As explained in wikipedia
    the shortest distance between a line and a dot, can be calculated as
    follows:

If the line passes through two points P1=(x1,y1) and P2=(x2,y2) then the distance of (x0,y0) from the line is:
Blockquote

  1. Java implimentaion

    class Point {
  double x,y;

  Point(double pX, double pY){
    this.x= pX;
    this.y= pY;
  }

  public double distance(Point A1, Point A2){
    double numerator = Math.abs((A2.y - A1.y)*this.x + (A2.x - A1.x)*this.y + A2.x*A1.y - A2.y*A1.x);
    double denominator = Math.sqrt(Math.pow(A2.y - A1.y,2) + Math.pow(A2.x - A1.x,2));

    return numerator/denominator;       
  }

}

To calculate the distance between Point B and the line defined by Points A1 and A2, you use the method distance like this:

public static void main (String[] args) throws java.lang.Exception
{
    Point A1 = new Point(0,3);
    Point A2 = new Point(2,0);
    Point B = new Point(0,0);

    System.out.println(
        B.distance(A1,A2)
    );
}

And here is the code up and running in ideone.

But pleas go buck to the basics, chose some good and funny coding book or tut and give it a go, happy coding 🙂

solved How to calculate shortest distance from path?