[R-sig-Geo] variance estimation in spgwr

[Takatsugu Kobayashi]

Hi,

I am curious if spgwr or some other spatial packages estimate local 
variances. I am particularly interested if gwr residuals are locally 
siginificant or not.  In this case, I believe I should estimate local 
variances.  I though an alternative to spgwr is gam in mgcv.

Suppose I have xy coordinates and some values d1 and d2 attached to 
point(x,y). z1 is related to z2, but this relationship is not spatially 
stationary. So I would set this up using gam:

model1 <- gam(d1 ~ s(x, y, by=d2)) : I am not quite familiar with 
adaptive bandwidth selections in gam...

or using spgwr

bw <- gwr.sel(d1~d2, coords=cbind(x,y), apapt=T)
model2 <- gwr(d1~d2, coords=cbind(x,y), apapt=T, bandwidth=bw, 
hatmatrix=TRUE, lonlat =FALSE)

What I would like to know is 

d1(i)-hat{d1(i)}/hat{sigma(i)}
where i denotes the ith location in a map.

I did a bit of search and "lokern" pacakge came up, but this is only for 
bivarriate case and not particularly spatial-oriented.

Sorry for ambiguity of my question...  I appreciate if someone could 
give me some clues.....

thanks

tk