code: public static <S extends DMatrix>
  	boolean jacobianR( FunctionNtoM func , FunctionNtoMxN<S> jacobian ,
  								 double param[] , double tol )
  	{
  		return jacobianR(func,jacobian,param,tol,Math.sqrt(UtilEjml.EPS));
  	}
docs: Checks the jacobian using a relative error threshold.
  @param tol fractional difference