Displaying 2 results from an estimated 2 matches for "nbgab".
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nab
2006 Jul 19
0
connection network - influence of site
...nstruct a distance matrix based on a nb object
created by spdep where sites must have a larger influence in one
direction then in the other.
Here is an example to better illustrate what I need:
Let say I have the following Gabriel connection network
library(spdep)
library(ade4)
data(orbatid)
nbgab<-graph2nb(gabrielneigh(as.matrix(oribatid$xy)))
plot(nbgab,oribatid$xy)
text(oribatid$xy,as.character(1:70),pos=1) # site number
arrows(-0.3,0,-0.3,10) # gradient direction
In that example, site 1 shouldn't influence site 2 (so it should have
a distance if 0 in the distance matrix). Howe...
2012 Sep 07
0
regions in Gabriel graph
Dear list,
following the vignette of the package 'spacemmakeR' I have built a
gabriel graph of ten randomly placed points:
library(spdep)
set.seed(3)
xyir<-matrix(runif(20),10,2)
nbgab<-graph2nb(gabrielneigh(xyir), sym=TRUE)
plot(nbgab,xyir,points=FALSE)
points(xyir,pch=20,cex=2,col=c(2,4,4,4,2,2,4,2,4,4))
title(main="Gabriel Graph")
Now, I need to determine for any additional point whether it is
located within the region surrounded by links between identically
colo...