extract info about voronoi cells

This function returns some info about the cells of a voronoi mosaic, including the coordinates of the vertices and the cell area.

Usage

cells(voronoi.obj)

Arguments

voronoi.obj: object of class voronoi

Details

The function calculates the neighbourhood relations between the underlying triangulation and translates it into the neighbourhood relations between the voronoi cells.

Value

retruns a list of lists, one entry for each voronoi cell which contains

cell: cell index
center: cell 'center'
neighbours: neighbour cell indices
nodes: 2 times nnb matrix with vertice coordinates
area: cell area

Author

A. Gebhardt

Note

outer cells have area=NA, currently also nodes=NA which is not really useful – to be done later

Examples

data(tritest)
tritest.vm <- voronoi.mosaic(tritest$x,tritest$y)
tritest.cells <- cells(tritest.vm)
# higlight cell 12:
plot(tritest.vm)
polygon(t(tritest.cells[[12]]$nodes),col="green")
# put cell area into cell center:
text(tritest.cells[[12]]$center[1],
     tritest.cells[[12]]$center[2],
     tritest.cells[[12]]$area)