R: Compute halfspace intersection about a point

halfspacen {geometry} | R Documentation

## Compute halfspace intersection about a point

### Description

Compute halfspace intersection about a point

### Usage

    halfspacen(p, fp, options = "Tv")

### Arguments

`p` | An `n`-by-`dim+1` matrix. Each row of `p` represents a halfspace by a `dim`-dimensional normal to a hyperplane and the offset of the hyperplane.
`fp` | A “feasible” point that is within the space contained within all the halfspaces.
`options` | String containing extra options, separated by spaces, for the underlying Qhull command; see details below and Qhull documentation at http://www.qhull.org/html/qhalf.htm.

### Value

A `dim`-column matrix containing the intersection points of the hyperplanes ../doc/qhull/html/qhalf.html. These points

### Author(s)

David Sterratt david.c.sterratt@ed.ac.uk

### References

Barber, C.B., Dobkin, D.P., and Huhdanpaa, H.T., “The Quickhull algorithm for convex hulls,” ACM Trans. on Mathematical Software, Dec 1996.

http://www.qhull.org

### See Also

`convhulln`

### Examples

    p <- rbox(0, C=0.5)  # Generate points on a unit cube centered around the origin
    ch <- convhulln(p, "n") # Generate convex hull, including normals to facets, with "n" option
    # Intersections of half planes
    # These points should be the same as the orginal points
    pn <- halfspacen(ch$normals, c(0, 0, 0))

[Package geometry version 0.4.0 Index]