R: Search for the enclosing Delaunay convex hull

tsearchn {geometry} | R Documentation

## Search for the enclosing Delaunay convex hull

### Description

For `t = delaunayn(x)`, where `x` is a set of points in N dimensions, `tsearchn(x, t, xi)` finds the index in `t` containing the points `xi`. For points outside the convex hull, `idx` is `NA`. `tsearchn` also returns the barycentric coordinates `p` of the enclosing triangles.

### Usage

    tsearchn(x, t, xi, ...)

### Arguments

`x` | An N-column matrix, in which each row represents a point in N-dimensional space.
`t` | A matrix with N+1 columns. A row of `t` contains indices into `x` of the vertices of an N-dimensional simplex. `t` is usually the output of delaunayn.
`xi` | An M-by-N matrix. The rows of `xi` represent M points in N-dimensional space whose positions in the mesh are being sought.
`...` | Additional arguments

### Details

If `x` is `NA` and the `t` is a `delaunayn` object produced by `delaunayn` with the `full` option, then use the Qhull library to perform the search. Please note that this is experimental in geometry version 0.4.0 and is only partly tested for 3D hulls, and does not yet work for hulls of 4 dimensions and above.

### Value

A list containing:

`idx`

  An M-long vector containing the indices of the row of `t` in which each point in `xi` is found.

`p`

  An M-by-N+1 matrix containing the barycentric coordinates with respect to the enclosing simplex of each point in `xi`.

### Note

Based on the Octave function Copyright (C) 2007-2012 David Bateman.

### Author(s)

David Sterratt

### See Also

tsearch, delaunayn

[Package geometry version 0.4.0 Index]