How to add a Vector3 parameter?

Sorry, if this is a very elementary problem. But I haven’t able to solve it for 5 straight coding days. :frowning:

I’m developing some quatrotor controller with ArduCopter V3.3-dev, which I think have the same parameter structure with 3.2. And for those controller, I need some additional parameters, some of them (e,g. inertia) are in vector form.
I’ve read about the article on how to add a parameters but still unable to pass the compiler: … overview….
Here is what I’ve done(for one of the parameter):
add parameter number k_param_ew_inertia @ Parameters.h
add variable declaration AP_Vector3f inertia below @ Parameters.h (AP_Vector3 won’t work as stated in the guiding page)
trying to get it work in Parameters.pde like:

     // @Param: EW_IXX
     // @DisplayName: Ewing inertia Ixx
     // @Description: inertia Ixx
     // @Range: 0 1000
     // @User: Advanced

    // @Param: EW_IYY
     // @DisplayName: Ewing inertia Iyy
     // @Description: inertia Iyy
     // @Range: 0 1000
     // @User: Advanced

     // @Param: EW_IZZ
     // @DisplayName: Ewing inertia Izz
     // @Description: inertia Izz
     // @Range: 0 1000
     // @User: Advanced
     GSCALAR(inertia,  "INERTIA", INERTIA_V3),

with defines in APM_Config.h as follows (Althought the guiding page told me to place in config.h, but config.h told me to do that in APM_Config.h)[/ul]

#define IXX_DEFAULT             0.002f
 #define IYY_DEFAULT             0.002f
 #define IZZ_DEFAULT             0.004f
 #define INERTIA_V3         Vector3f(IXX_DEFAULT,  IYY_DEFAULT,   IZZ_DEFAULT)

[ul]the compiler gives the error:[/ul]

I do understand since I use the G-SCALAR it should be scalar, right? Then how should I do this right?
I’ve tried to initialize the AP_Vectors3 in initializers of Parameters.h like:

Then compiler would give:

And call that in the constructor won’t work either.

So who do I do a Vector3 parameter exactly? Is there anything I’ve missed or misunderstand?

The parameter part of the code is a little difficult for me and I’m not quite understand it.
I appreciate anyone who read this and any advice is wellcome!