[R-sig-Geo] About dnearneight and nb2listw function

[Letícia Dal' Canton]

I am forwarding the routine used and the part of the database I am interested in, which uses georeferenced agricultural data.

require(spdep)
require(geoR)

dados = read.geodata("test.txt", header = T)
dados

coord=dados$coord

max(dist(coord))/2

grid = dnearneigh(dados$coord, 0, 880)

lw=nb2listw(grid,zero.policy=TRUE)


>From this routine, I will try to explain more clearly what my doubts are:

1) The "dnearneight" function provides the neighbor list object. Is there any way to numerically visualize who the neighbors are?

2) The "nb2listw" function provides the "Characteristics of weights list object". When requesting the weights (lw$w in the routine), the n points are listed and values are assigned (who are these values?) And why are not the n values associated to the remaining n-1. Because in "attr (," comp ") $ d" it is noticeable that each point is associated to a different amount of points. For example, with the database used, the first point is associated to another 57, the second to another 65. Why does this occur?

Thankfully,


Let�cia Dal' Canton.

Matem�tica.
Mestre em Engenharia Agr�cola.
Doutoranda em Engenharia Agr�cola com linha de pesquisa em Estat�stica Espacial.
Universidade Estadual do Oeste do Paran� - UNIOESTE.

Curr�culo Lattes: http://lattes.cnpq.br/1085422685501012.
Contato: (45) 9 9962-7492.

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