use nbcosts() with geographic openstreetmap distance as weights
On Wed, 4 Aug 2021, Germ?n Gallego via R-sig-Geo wrote:
I am conducting a study of Regionalization for the Ministry of Health of Colombia, using a MST and SKATER algorithm proposed by Assauncao. I have included 121 social and health covariates sumarized on a SImilarity matrix (After Explratory Factor analysis dimensiionality treatment). that will be used into skater function. I am using a spatialpolygons dataframe with the 1081 municipalities that I've proccesed with nb2list() function. Also I have the geographic distance (extracted from openstreetmaps) from each capital city to anotherone, and I want to use it in nbcosts() function. When I read the nbcosts documentation I read that the data must be in dataframe class object but what i have is a dist object. The code does not show any error but im not sure how the dist object is computing it.
ady <- poly2nb(colpeso.utmsub)
adycostsdist <- nbcosts(ady,distkmat1)
class(distkmat1)
[1] "dist"
I suppose that I have to covert a dist object into a nbdist object? or find the way to use it properly into nbcost function,
No, this is not a sensible way of using this approach. The data.frame should contain observations for the spatial objects on variables relevant for the regionalization being undertaken, not a distance matrix. These variables might be demographic, socio-economic, or others relevant to the regionalization. It is the "distance" in variable, not geographic, space that is used to weight the edges of the graph, so that less similar edges are dropped and more similar edges retained. The geographical distances between observations are implicit in the neighbour graph - see https://keen-swartz-3146c4.netlify.app/area.html#higher-order-neighbours for a discussion. Run example(skater) to see that four variables are used in the dpad data.frame. Hope this clarifies, Roger
I'll apreciate your opinion on this.? Thank you in advance [[alternative HTML version deleted]]
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Roger Bivand Emeritus Professor Department of Economics, Norwegian School of Economics, Postboks 3490 Ytre Sandviken, 5045 Bergen, Norway. e-mail: Roger.Bivand at nhh.no https://orcid.org/0000-0003-2392-6140 https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en