Neighbours list based on \(k\) nearest neighbours

In two steps:

1. knearneigh(): create a knn object (‘k-nearest neighbour classification’)
   • it contains nn: a matrix that defines the k nearest neighbors
2. knn2nb(): convert the knn object to a neighbours list

knn_centroids <- knearneigh(centroids, k = 3)
class(knn_centroids)

## [1] "knn"

class(knn_centroids$nn)

## [1] "matrix" "array"

head(knn_centroids$nn)

##      [,1] [,2] [,3]
## [1,]    3    2    4
## [2,]    4    1    8
## [3,]    5    4    1
## [4,]    8    2    7
## [5,]   11    8    3
## [6,]    9    5   10