inconsistent results from moran.test()
On Fri, 8 Mar 2019, Jay Wang wrote:
Hello, Having my own spatial weight matrix, I converted it to a listw format and calculated the Moran index. The codes are listed below: Wod_lw<-mat2listw(Wod) moran.test(mydata$Ties_processed,Wod_lw, randomisation=TRUE)
Here, Wod_lw has an unknown style, "M" for matrix.
However, after I generated a gal file, imported it, converted it back to a listw file, and re-calculated the Moran index with the following codes, the results became totally different (0.1624 vs. 0.1942): write.nb.gal(Wod_lw$neighbours,"Wod.gal")
This only writes the neighbours (read the help page), not the weights.
Wod.gal.nb <- read.gal(file="Wod.gal") Wod_lw2<-nb2listw(Wod.gal.nb)
The default style in nb2listw() is "W", row standardised. What does: all.equal(Wod_lw$weights, Wod_lw2$weights, check.attributes=FALSE) say? And: all.equal(Wod_lw$neighbours, Wod_lw2$neighbours, check.attributes=FALSE)
moran.test(mydata$Ties_processed,Wod_lw, randomisation=TRUE) moran.test(mydata$Ties_processed,Wod_lw2, randomisation=TRUE) I don't know where the problem is. I would appreciate if anyone can help me with this. Thank you
Do read the help pages, you'll find they explain these things. Roger
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Roger Bivand Department of Economics, Norwegian School of Economics, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; e-mail: Roger.Bivand at nhh.no https://orcid.org/0000-0003-2392-6140 https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en