Defining who is a neighbour and who isn’t

• contiguity criteria – this needs polygons:
  • the areas that share at least a common vertex (type Queen)
  • the areas that share a common border (type Rook)
• distance criteria – this needs points (e.g. polygon centroids):
  • the areas that are within some distance apart (lower and upper bounds)
  • the areas that are among the \(k\) nearest to an area (asymmetric relationship)