code: public static boolean gradient( FunctionNtoS func , FunctionNtoN gradient ,
  									double param[] , double tol )
  	{
  		return gradient(func, gradient, param, tol, Math.sqrt(UtilEjml.EPS));
  	}
docs: Compares the passed in gradient function to a numerical calculation.  Comparison is done using
  an absolute value.
  @return true for within tolerance and false otherwise