spatstat (version 1.31-3)

delaunay.distance: Distance on Delaunay Triangulation

Description

Computes the graph distance in the Delaunay triangulation of a point pattern.

Usage

delaunay.distance(X)

Arguments

X

Spatial point pattern (object of class "ppp").

Value

• A symmetric square matrix with integer entries.

Details

The Delaunay triangulation of a spatial point pattern X is defined as follows. First the Dirichlet/Voronoi tessellation of X computed; see dirichlet. Then two points of X are defined to be Delaunay neighbours if their Dirichlet/Voronoi tiles share a common boundary. Every pair of Delaunay neighbours is joined by a straight line.

The graph distance in the Delaunay triangulation between two points X[i] and X[j] is the minimum number of edges of the Delaunay triangulation that must be traversed to go from X[i] to X[j].

This command returns a matrix D such that D[i,j] is the graph distance between X[i] and X[j].

See Also

delaunay

Examples

X <- runifpoint(20)
  M <- delaunay.distance(X)
  plot(delaunay(X), lty=3)
  text(X, labels=M[1, ], cex=2)