[R-sig-Geo] error in errorsarlm

[Roger Bivand]

On Thu, 12 Aug 2010, elaine kuo wrote:

> Dear List,
>
>
>
> Eventually computing lagsarlm and errorsarlm become successful,
>
> Using the code below. (maybe knearneigh helps to solve some issue.)
>
> (ref. An Introduction to Spatial Regression Analysis in R, Luc Anselin,
> 2003)

Or more recently Bivand et al. (2008) Applied Spatial Data Analysis with R 
(Springer), ch. 9-10, (see www.asdar-book.org).

I am concerned that you still do not know what you are doing!

You continue to use lat as your x dimension and lon as your y dimension, 
this is very confused and most likely wrong. In addition, because you do 
not work on this thread regularly (gaps of days or weeks), it is difficult 
to tell whether you are still working in decimal degrees, in which case 
your whole analysis is compromised - you should use cbind(lon, lat) then 
longlat=TRUE in all the neighbour finding steps to use Great Circle 
distances.

As I said at the beiginning of the thread, your use of arguments in 
functions is sloppy, and the reason why things now work is because you 
have changed some arguments. Whether the changes were appropriate or not 
is a very different question.

Roger

>
>
> Elaine
>
>
>
>
> code
>
>
>
> rm(list=ls())
>
> datam <-read.csv("c:/migration/Mig_ratio_20100808.csv",header=T,
> row.names=1)
>
>
>
> library(ncf)
>
> library(spdep)
>
>
>
>    # get the upper bound
>
>      up <- knearneigh(cbind(datam$lat,datam$lon))
>
>      upknn <- knn2nb(up)
>
>      updist1 <- nbdists(upknn,cbind(datam$lat,datam$lon))
>
>      updist1
>
>      updistvec <- unlist(updist1)
>
>      updistvec
>
>      upmaxd <- max(updistvec)
>
>      upmaxd
>
>
>
> # Define coordinates, neighbours, and spatial weights
>
>      coords<-cbind(datam$lat,datam$lon)
>
>      coords<-as.matrix(coords)
>
>
>
>    # Define neighbourhood (here distance 8)
>
>      nb8<-dnearneigh(coords,0,8.12)
>
>      summary(nb8)
>
>
>
>      #length(nb8)
>
>      #sum(card(nb8))
>
>
>
>    # Spatial weights, illustrated with coding style "W" (row standardized)
>
>      nb8.w<-nb2listw(nb8, glist=NULL, style="W")
>
>
>
>
>
>    # std model
>
>       datam.sd<-scale(datam)
>
>       datam.std<-as.data.frame(datam.sd)
>
>       summary (datam.std)
>
>       mean(datam.std)
>
>
>
>          # obtain standard deviation
>
>          sd(datam.std)
>
>
>
>       mig.std <-lm(datam.std$S ~ datam.std$coast + datam.std$topo_var
> +datam.std$prec_ran, data = datam.std)
>
>       summary(mig.std)
>
>
>
> # Spatial SAR error model
>
>    mignb8.err <- errorsarlm(datam.std$S ~ datam.std$coast +
> datam.std$topo_var +datam.std$prec_ran, data = datam.std, listw=nb8.w,
> na.action=na.omit, method="Matrix", zero.policy=TRUE)
>
>    summary(mignb8.err)
>
>
>
>
>
> # Spatial SAR lag model
>
>     mignb8.lag <- lagsarlm(datam.std$S ~ datam.std$coast +
> datam.std$topo_var +datam.std$prec_ran, data = datam.std, data=datam.std,
> listw=nb8.w, na.action=na.omit, method="Matrix", zero.policy=TRUE)
>
>     summary(mignb8.lag)
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

-- 
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