alphahull (version 2.3)

tricircum: Returns the circumcentres of a Delaunay triangulation

Description

This function converts a triangulation data structure to a triangle list with vertexes, opposite triangles and arcs indexes. It also returns the coordinates of the circumcentre of each triangle.

Usage

tricircum(tri.obj)

Arguments

tri.obj

Object of class "tri", see tri.mesh from package tripack.

Value

tri.info

A \(n.tri\)-row matrix, where \(n.tri\) is the total number of different triangles of the Delaunay triangulation. For each row i, tri.info[i,] contains the vertex nodal indexes (first three columns), the indexes of the triangles and arcs which are opposite to the triangle i (columns 4-9) and the coordinates of the circumcentre of the triangle i (columns 10-11).

Details

The function tricircum calls the Fortran function delaunaycircum and it is internally used in the function delvor.

References

Renka, R. J. (1996). Algorithm 751: TRIPACK: a constrained two-dimensional Delaunay triangulation package, ACM Trans. Math. Softw., 22(1), pp.1-8.

Examples

# NOT RUN {
# Random sample in the unit square
x <- runif(20)
y <- runif(20)
del <- tricircum(tri.mesh(x, y))
# }