/**
    * This is some of Nicky's wizardry.
    * It calculates the heading from 1 lat/lon to another lat/lon
    */
    public static int getHeading( double oldlat, double oldlon, double newlat, double newlon ) {
        System.out.println("Called with " + Double.toString(newlat) + "," + Double.toString(newlon) +
                " : " + Double.toString(oldlat) + "," + Double.toString(oldlon)
                );

        if (newlon == oldlon){
            if (newlat < oldlat)
                return 180;
            else
                return 0;
        }

        if (newlat == oldlat){
            if (newlon > oldlon)
                return 90;
            else if (newlon < oldlon)
                return 270;
        }

        if ((newlat > oldlat) && (newlon > oldlon)) {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs( newlon - oldlon );
            double ratio = difflon / difflat;
            double tmp = mMath.atan( ratio  );
            return (int) java.lang.Math.toDegrees(tmp);
        } else if ((newlon > oldlon) && (newlat < oldlat))
            return 180 - (int) java.lang.Math.toDegrees(mMath.atan( java.lang.Math.abs( newlon - oldlon ) / java.lang.Math.abs(newlat - oldlat) ));
        else if ((newlat < oldlat) && (newlon < oldlon)) {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs( newlon - oldlon );
            double ratio = difflon/ difflat;
            double tmp = mMath.atan( ratio  );
            return 180 + (int) java.lang.Math.toDegrees(tmp);
        } else {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs( newlon - oldlon );
            double ratio = difflon / difflat;
            double tmp = mMath.atan( ratio  );
            return 360 - (int) java.lang.Math.toDegrees(tmp);
        }

    }