BrownianIsland java in a pgm

BrownianIsland.java

public class BrownianIsland

{

 public static void midpoint(double x0, double y0, double x1, double y1, double var, int N)

   {

        if (N == 0)

        {

            StdDraw.line(x0, y0, x1, y1);

            return;

        }

        double xmid = 0.5 * (x0 + x1) + StdRandom.gaussian(0, Math.sqrt(var));

        double ymid = 0.5 * (y0 + y1) + StdRandom.gaussian(0, Math.sqrt(var));

        midpoint(x0, y0, xmid, ymid, var / 2.7, N-1); 

        midpoint(xmid, ymid, x1, y1, var / 2.7, N-1);

    }

                  public static void main(String[] args)

                 {

        double var = Double.parseDouble(args[0]);

        int N = Integer.parseInt(args[1]);

        StdDraw.clear(StdDraw.LIGHT_GRAY);

        StdDraw.setXscale(-1, +1);

        StdDraw.setYscale(-1, +1);

        midpoint(0, 0, 0, 0, var / Math.sqrt(2), N);

    }

}