code: static double quardMinimizer(
  			double u, 
  			double fu, 
  			double du, 
  			double v, 
  			double fv
  			) 
  	{
  		double a = v - u;
  	    double qm = u + du / ((fu - fv) / a + du) / 2 * a;
  	    return qm;
  	}
docs: Find a minimizer of an interpolated quadratic function.
  @param  u       The value of one point, u.
  @param  fu      The value of f(u).
  @param  du      The value of f'(u).
  @param  v       The value of another point, v.
  @param  fv      The value of f(v).
  @return	double  The minimizer of the interpolated quadratic.