[R-sig-Geo] About adaptive spatial kernel for spgwr

[Hisaji Ono]

Thank you very much, Mr. Yu.

> 
>     I think Fortheringham and collegues are using the cross-validation to
> obtain an optimal number of nearest neighbor to replace the optimal
> bandwidth. This way, every data point will have the same number of
> observations participating the locally weighted regression.
>     I cannot actually implement the code in R myself, but I would like to
> list my understanding of using the cross-validation procedure to obtain
> the optimal number of nearest neighbors. If I am wrong in any aspect,
> please correct me:
>     1. Choose the weighting scheme (bi-squre, or similar ones like
> tri-cube);
>     2. Set the minimum number of nearest neighbor as the number of
> explanatory variables plus 2, and the maximum number as the number of
> observations (I guess for large number of observations, this may be very
> computational intensive);
>     3. Loop through the minimum to the maximum, and obtain a CV score for
> each number of nearest neighbor;
>     4. The smallest CV yields the optimal number of nearest neighbor.
> 
>     I hope this will help.

 It's very helpful.