tile.list {deldir} | R Documentation |
For each point in the set being tessellated produces a list entry describing the Dirichlet/Voronoi tile containing that point.
tile.list(object)
object |
An object of class |
A list with one entry for each of the points in the set being tesselated. Each entry is in turn a list with components
pt |
The coordinates of the point whose tile is being described. |
x |
The |
y |
The |
bp |
Vector of logicals indicating whether the tile vertex is a “real” vertex, or a boundary point, i.e. a point where the tile edge intersects the boundary of the enclosing rectangle |
The author expresses sincere thanks to Majid Yazdani who found and
pointed out a serious bug in tile.list
in a previous version
(0.0-5) of the deldir
package.
The set of vertices of each tile may be “incomplete”. Only vertices which lie within the enclosing rectangle, and “boundary points” are listed.
Note that the enclosing rectangle may be specified by the user
in the call to deldir()
.
In contrast to some earlier versions of deldir
, the corners
of the enclosing rectangle are now include as vertices of tiles.
I.e. a tile which in fact extends beyond the rectangular window and
contains a corner of that window will have that corner added to its
list of vertices. Thus when the corresponding polygon is plotted,
the result is the intersection of the tile with the enclosing
Rolf Turner r.turner@auckland.ac.nz http://www.math.unb.ca/~rolf
deldir()
, plot.tile.list()
x <- runif(20) y <- runif(20) z <- deldir(x,y) w <- tile.list(z) z <- deldir(x,y,rw=c(0,1,0,1)) w <- tile.list(z) z <- deldir(x,y,rw=c(0,1,0,1),dpl=list(ndx=2,ndy=2)) w <- tile.list(z)