# has.close

##### Check Whether Points Have Close Neighbours

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, …)` # S3 method for default
has.close(X,r, Y=NULL, …, periodic=FALSE)

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

# S3 method for 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`

.

##### See Also

##### Examples

```
# NOT RUN {
has.close(redwood, 0.05)
with(split(amacrine), has.close(on, 0.05, off))
with(osteo, sum(has.close(pts, 20)))
# }
```

*Documentation reproduced from package spatstat, version 1.55-1, License: GPL (>= 2)*