# clickjoin

##### Interactively join vertices on a plot

Given a point pattern representing a set of vertices, this command gives a point-and-click interface allowing the user to join pairs of selected vertices by edges.

##### Usage

`clickjoin(X, …, add = TRUE, m = NULL, join = TRUE)`

##### Arguments

- X
Point pattern of vertices. An object of class

`"ppp"`

.- …
Arguments passed to

`segments`

to control the plotting of the new edges.- add
Logical. Whether the point pattern

`X`

should be added to the existing plot (`add=TRUE`

) or a new plot should be created (`add=FALSE`

).- m
Optional. Logical matrix specifying an initial set of edges. There is an edge between vertices

`i`

and`j`

if`m[i,j] = TRUE`

.- join
Optional. If

`TRUE`

, then each user click will join a pair of vertices. If`FALSE`

, then each user click will delete an existing edge. This is only relevant if`m`

is supplied.

##### Details

This function makes it easier for the user to create a linear network or a planar graph, given a set of vertices.

The function first displays the point pattern `X`

,
then repeatedly prompts the user to click on a pair of points in `X`

.
Each selected pair of points will be joined
by an edge. The function returns a
logical matrix which has entries equal to `TRUE`

for each
pair of vertices joined by an edge.

The selection of points is performed
using `identify.ppp`

which typically expects the user to
click the left mouse button. This point-and-click interaction
continues until the user terminates it,
by pressing the middle mouse button,
or pressing the right mouse button and selecting `stop`

.

The return value can be used in `linnet`

to create a linear network.

##### Value

Logical matrix `m`

with value `m[i,j] = TRUE`

for every
pair of vertices `X[i]`

and `X[j]`

that should be joined by
an edge.

##### See Also

*Documentation reproduced from package spatstat, version 1.61-0, License: GPL (>= 2)*