# connected.ppp

##### Connected Components of a Point Pattern

Finds the topologically-connected components of a point pattern, when all pairs of points closer than a threshold distance are joined.

##### Usage

```
# S3 method for ppp
connected(X, R, …)
```# S3 method for pp3
connected(X, R, …)

##### Arguments

- X
A point pattern (object of class

`"ppp"`

or`"pp3"`

).- R
Threshold distance. Pairs of points closer than

`R`

units apart will be joined together.- …
Other arguments, not recognised by these methods.

##### Details

This function can be used to identify clumps of points in a point pattern.

The function `connected`

is generic. This file documents the methods for
point patterns in dimension two or three (objects of class `"ppp"`

or
`"pp3"`

).

The point pattern `X`

is first converted into an abstract graph
by joining every pair of points that lie closer than `R`

units
apart. Then the connected components of this graph are identified.

Two points in `X`

belong to the same connected component if they
can be reached by a series of steps between points of `X`

,
each step being shorter than `R`

units in length.

The result is a vector of labels for the points of `X`

where all the points in a connected component have the same label.

##### Value

A point pattern, equivalent to `X`

except that the points
have factor-valued marks, with levels corresponding to the
connected components.

##### See Also

##### Examples

```
# NOT RUN {
Y <- connected(redwoodfull, 0.1)
if(interactive()) {
plot(Y, cols=1:length(levels(marks(Y))),
main="connected(redwoodfull, 0.1)")
}
X <- osteo$pts[[1]]
Z <- connected(X, 32)
if(interactive()) {
plot(Z, col=marks(Z), main="")
}
# }
```

*Documentation reproduced from package spatstat, version 1.63-2, License: GPL (>= 2)*