I'm using the function ggwr (for the first time). I want to test the significance of the coeff. estimates (global), but I can't find their standard errors. I used the following code: xx<-SpatialPointsDataFrame(coords=coord,data=en1) bw <- ggwr.sel(numhomicidio~offset(log(popmedia))+I12 + I4 + I5 + I10,data=xx,family=quasipoisson()) ed_quasi<-ggwr(numhomicidio~offset(log(popmedia))+I12 + I4 + I5 + I10, data=xx,family=quasipoisson(),bandwidth=bw) Thanks Nelson
coff standard erros in ggwr
2 messages · Nelson Oliveira, Roger Bivand
On Tue, 16 Sep 2008, Nelson Oliveira wrote:
I'm using the function ggwr (for the first time). I want to test the significance of the coeff. estimates (global), but I can't find their standard errors. I used the following code: xx<-SpatialPointsDataFrame(coords=coord,data=en1) bw <- ggwr.sel(numhomicidio~offset(log(popmedia))+I12 + I4 + I5 + I10,data=xx,family=quasipoisson()) ed_quasi<-ggwr(numhomicidio~offset(log(popmedia))+I12 + I4 + I5 + I10, data=xx,family=quasipoisson(),bandwidth=bw)
The local coefficient standard error estimates are not calculated or returned by ggwr(). They could in principle be computed, but would you trust them? Since gwr() and ggwr() are seriously affected by induced collinearity, I doubt whether inference is where one wants to go. Please do try: pairs(as(ed_quasi$SDF, "data.frame")[, 2:5]) for a quick check (Wheeler & Tiefelsdorf, 2005). Roger
Thanks Nelson
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no