R: Returns the circumcentres of a Delaunay triangulation

tricircum {alphahull} | R Documentation

## 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.

### Details

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

### 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).

### 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))

    ## End(Not run)

[Package alphahull version 2.2 Index]