Computes the Dirichlet-Voronoi tessellation of a point pattern and extracts the vertices or edges of the tiles.

`dirichletVertices(X)`dirichletEdges(X)

X

Point pattern (object of class `"ppp"`

).

`dirichletVertices`

returns a point pattern (object of class `"ppp"`

) in the same window
as `X`

.

`dirichletEdges`

returns a line segment pattern (object of
class `"psp"`

).

These function compute the Dirichlet-Voronoi tessellation of `X`

(see `dirichlet`

)
and extract the vertices or edges of the tiles of the tessellation.

The Dirichlet vertices are the spatial locations which are locally
farthest away from `X`

, that is, where the distance function
of `X`

reaches a local maximum.

The Dirichlet edges are the dividing lines equally distant between
a pair of points of `X`

.

The Dirichlet tessellation of `X`

is computed
using `dirichlet`

. The vertices or edges of all
tiles of the tessellation are extracted.

For `dirichletVertices`

, any vertex which
lies on the boundary of the window of `X`

is deleted.
The remaining vertices are returned, as a point pattern,
without duplicated entries.

# NOT RUN { plot(dirichlet(cells)) plot(dirichletVertices(cells), add=TRUE) ed <- dirichletEdges(cells) # }