[R-sig-Geo] globalG.test - routine with distance based neighbours

[Roger Bivand]

On Fri, 5 Feb 2016, Francesco Perugini wrote:

> Dear Prof. Bivand,
> thanks a lot for the reply.
> sure, it should be c(0.620, 0.650, 0.700).
> sorry but "There is no dnb[[620]], it is length(dnb) == length(z) long", is

You cannot use (val in z) to index dnb, which takes the integers 1:3 only. 
Previously, your k was an integer sequence.

Roger

> not clear to me.
> Many thanks.
> Regards.
> franc.per
>
> 2016-02-05 13:27 GMT+01:00 Roger Bivand <Roger.Bivand at nhh.no>:
>
>> On Fri, 5 Feb 2016, Francesco Perugini wrote:
>>
>> Dear all,
>>> I've routine that plot Glogal G statistics at different k-neighbours. I've
>>> tried to run it using distance based neighbours method but I got this
>>> message:
>>>
>>> Error in dnb[[val]] : subscript out of bounds
>>>
>>
>> val is defined in for (val in z), and z in z <- c(620, 650, 700) -
>> arguably should be c(0.620, 0.650, 0.700) given all.linkedT as 0.619. There
>> is no dnb[[620]], it is length(dnb) == length(z) long.
>>
>> Roger
>>
>>
>>> Any suggestion on this?
>>>
>>> Thanks a lot.
>>>
>>> franc.per
>>>
>>> _______________
>>>
>>> this is the routine
>>>
>>> library(spdep)
>>> example(columbus)
>>> coord <- coordinates(columbus)
>>>
>>> #k-nearest neighbours
>>> #z <- c(1:20)
>>> #neighbors.knn <- list()
>>>
>>>
>>> #Distance-based neighbours
>>> k1 <- knn2nb(knearneigh(coord,k=1,longlat=F))
>>> all.linkedT <- max(unlist(nbdists(k1, coord,longlat=F)))
>>> all.linkedT
>>>
>>> z <- c(620, 650, 700)
>>> dnb <- list()
>>> for (val in z)
>>>  {
>>>  dnb <- c(dnb, list(dnearneigh(coord, 0, val, longlat=F)))
>>> # neighbors.knn <- c(neighbors.knn, list(knn2nb(knearneigh(coord, val,
>>> longlat=F), sym=F)))
>>>  }
>>> list(dnb)
>>>
>>>
>>> ndists <- length(z)
>>> ZG <- vector(mode="list", length=ndists)
>>> names(ZG) <- as.character(z)
>>>
>>> f <- c("CRIME", "INC")
>>> for (val in z)
>>>  {
>>> # dlwknn.B <- nb2listw(neighbors.knn[[val]], style="B", zero.policy=TRUE)
>>>  dlwdnb.B <- nb2listw(dnb[[val]], style="B", zero.policy=TRUE)
>>>  temp <- list()
>>>
>>>  for (var in f)
>>>  {
>>> #   temp <- c(temp, list(globalG.test(columbus[[var]], dlwknn.B,
>>> zero.policy=F)))
>>>    temp <- c(temp, list(globalG.test(columbus[[var]], dlwdnb.B,
>>> zero.policy=F)))
>>>  }
>>>  ZG[[val]] <- temp
>>> }
>>>
>>> t(sapply(lapply(ZG, "[[", 1), function(var) c(var$estimate[1],
>>>                                      var$statistic,
>>> p.value=unname(var$p.value))))
>>> CRIME <- t(sapply(lapply(ZG, "[[", 1), function(var) c(var$estimate[1],
>>>                                      var$statistic,
>>> p.value=unname(var$p.value))))
>>> plot(z, CRIME[,1], xlab="distance", ylab="Global G", xlim=NULL,
>>> axes=TRUE, type="o", col="blue")
>>>
>>>         [[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo at r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>>
>> --
>> Roger Bivand
>> Department of Economics, Norwegian School of Economics,
>> Helleveien 30, N-5045 Bergen, Norway.
>> voice: +47 55 95 93 55; fax +47 55 95 91 00
>> e-mail: Roger.Bivand at nhh.no
>> http://orcid.org/0000-0003-2392-6140
>> https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
>> http://depsy.org/person/434412
>>
>
> 	[[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

-- 
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no
http://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
http://depsy.org/person/434412