R: Tabulate Marks in Neighbourhood of Every Point in a Point...

marktable {spatstat.core} | R Documentation

## Tabulate Marks in Neighbourhood of Every Point in a Point Pattern

### Description

Visit each point in a point pattern, find the neighbouring points, and compile a frequency table of the marks of these neighbour points.

### Usage

       marktable(X, R, N, exclude=TRUE, collapse=FALSE)

### Arguments

`X` | A marked point pattern. An object of class `"ppp"`.
`R` | Neighbourhood radius. Incompatible with `N`.
`N` | Number of neighbours of each point. Incompatible with `R`.
`exclude` | Logical. If `exclude=TRUE`, the neighbours of a point do not include the point itself. If `exclude=FALSE`, a point belongs to its own neighbourhood.
`collapse` | Logical. If `collapse=FALSE` (the default) the results for each point are returned as separate rows of a table. If `collapse=TRUE`, the results are aggregated according to the type of point.

### Details

This algorithm visits each point in the point pattern `X`, inspects all the neighbouring points within a radius `R` of the current point (or the `N` nearest neighbours of the current point), and compiles a frequency table of the marks attached to the neighbours.

The dataset `X` must be a multitype point pattern, that is, `marks(X)` must be a `factor`.

If `collapse=FALSE` (the default), the result is a two-dimensional contingency table with one row for each point in the pattern, and one column for each possible mark value. The `[i,j]` entry in the table gives the number of neighbours of point `i` that have mark `j`.

If `collapse=TRUE`, this contingency table is aggregated according to the type of point, so that the result is a contingency table with one row and one column for each possible mark value. The `[i,j]` entry in the table gives the number of neighbours of a point with mark `i` that have mark `j`.

To perform more complicated calculations on the neighbours of every point, use `markstat` or `applynbd`.

### Value

A contingency table (object of class `"table"`). If `collapse=FALSE`, the table has one row for each point in `X`, and one column for each possible mark value. If `collapse=TRUE`, the table has one row and one column for each possible mark value.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au

and Rolf Turner r.turner@auckland.ac.nz

### See Also

`markstat`, `applynbd`, `Kcross`, `ppp.object`, `table`

### Examples

      head(marktable(amacrine, 0.1))
      head(marktable(amacrine, 0.1, exclude=FALSE))
      marktable(amacrine, N=1, collapse=TRUE)

[Package spatstat.core version 1.65-5 Index]