R: Check Whether Points Have Close Neighbours

has.close {spatstat.geom} | R Documentation

## Check Whether Points Have Close Neighbours

### Description

For each point in a point pattern, determine whether the point has a close neighbour in the same pattern.

### Usage

      has.close(X, r, Y=NULL, ...)

      ## Default S3 method:
    has.close(X,r, Y=NULL, ..., periodic=FALSE)

      ## S3 method for class 'ppp'
    has.close(X,r, Y=NULL, ..., periodic=FALSE, sorted=FALSE)

      ## S3 method for class 'pp3'
    has.close(X,r, Y=NULL, ..., periodic=FALSE, sorted=FALSE)

### Arguments

`X,Y` | Point patterns of class `"ppp"` or `"pp3"` or `"lpp"`.
`r` | Threshold distance: a number greater than zero.
`periodic` | Logical value indicating whether to measure distances in the periodic sense, so that opposite sides of the (rectangular) window are treated as identical.
`sorted` | Logical value, indicating whether the points of `X` (and `Y`, if given) are already sorted into increasing order of the x coordinates.
`...` | Other arguments are ignored.

### Details

This is simply a faster version of `(nndist(X) <= r)` or `(nncross(X,Y,what="dist") <= r)`.

`has.close(X,r)` determines, for each point in the pattern `X`, whether or not this point has a neighbour in the same pattern `X` which lies at a distance less than or equal to `r`.

`has.close(X,r,Y)` determines, for each point in the pattern `X`, whether or not this point has a neighbour in the other pattern `Y` which lies at a distance less than or equal to `r`.

The function `has.close` is generic, with methods for `"ppp"` and `"pp3"` and a default method.

### Value

A logical vector, with one entry for each point of `X`.

### Author(s)

Adrian Baddeley Adrian.Baddeley@curtin.edu.au.

### See Also

`nndist`

### Examples

      has.close(redwood, 0.05)
      with(split(amacrine), has.close(on, 0.05, off))
      with(osteo, sum(has.close(pts, 20)))

[Package spatstat.geom version 2.2-0 Index]