# insertVertices

##### Insert New Vertices in a Linear Network

Adds new vertices to a linear network at specified locations along the network.

##### Usage

`insertVertices(L, …)`

##### Arguments

- L
Linear network (object of class

`"linnet"`

) or point pattern on a linear network (object of class`"lpp"`

).- …
Additional arguments passed to

`as.lpp`

specifying the positions of the new vertices along the network.

##### Details

This function adds new vertices at locations along an existing linear network.

The argument `L`

can be either a linear network (class
`"linnet"`

) or some other object that includes a linear network.

The new vertex locations can be specified either as a
point pattern (class `"lpp"`

or `"ppp"`

)
or using coordinate vectors `x,y`

or `seg,tp`

or `x,y,seg,tp`

as explained in the help for `as.lpp`

.

This function breaks the existing line segments
of `L`

into pieces at the locations specified by
the coordinates `seg,tp`

and creates new vertices at these
locations.

The result is the modified object, with an attribute `"id"`

such that
the `i`

th added vertex has become the
`id[i]`

th vertex of the new network.

##### Value

An object of the same class as `L`

representing the result of
adding the new vertices.
The result also has an attribute `"id"`

as described in Details.

##### See Also

`addVertices`

to create new vertices at locations which
are not yet on the network.

##### Examples

```
# NOT RUN {
opa <- par(mfrow=c(1,3), mar=rep(0,4))
simplenet
plot(simplenet, main="")
plot(vertices(simplenet), add=TRUE)
# add two new vertices at specified local coordinates
L <- insertVertices(simplenet, seg=c(3,7), tp=c(0.2, 0.5))
L
plot(L, main="")
plot(vertices(L), add=TRUE)
id <- attr(L, "id")
id
plot(vertices(L)[id], add=TRUE, pch=16)
# add new vertices at three randomly-generated points
X <- runiflpp(3, simplenet)
LL <- insertVertices(simplenet, X)
plot(LL, main="")
plot(vertices(LL), add=TRUE)
ii <- attr(LL, "id")
plot(vertices(LL)[ii], add=TRUE, pch=16)
par(opa)
# }
```

*Documentation reproduced from package spatstat, version 1.64-1, License: GPL (>= 2)*