# Class dg.VertexEdge

### Description

The class for edges between vertices.

### Details

Edges are not constrained to have two vertices.

### Objects from the Class

Objects has the methods for extracting and setting the slots for edges, and the method for drawing the edge.

### Slots

`oriented`

:Object of class

`"logical"`

. If`oriented`

is`NA`

then the edge is drawn as an arrow if the vertices of the edge are in different blocks, oriented according to the strata of the blocks. If`oriented`

is`NA`

and the vertices of the edge are in the same block, then an undirected edge is drawn. If`oriented`

is TRUE then an arrow is drawn from the first vertex of the edge to the second. If`oriented`

is FALSE then an undirected edge is drawn, also between blocks.`vertex.indices`

:Object of class

`"numeric"`

, see`"dg.Edge"`

. These are the indices of the vertices in the list of vertices.`width`

:Object of class

`"numeric"`

, see`"dg.Edge"`

.`dash`

:Object of class

`"character"`

, see`"dg.Edge"`

.`color`

:Object of class

`"character"`

, see`"dg.Edge"`

.`label`

:Object of class

`"character"`

, see`"dg.Edge"`

.`label.position`

:Object of class

`"numeric"`

, see`"dg.Edge"`

.

### Extends

Class `"dg.Edge"`

, directly.
Class `"dg.Node"`

, directly.

### Methods

- nodeTypesOfEdge
`signature(object = "dg.VertexEdge")`

: ...- oriented<-
`signature(x = "dg.VertexEdge")`

: ...- oriented
`signature(object = "dg.VertexEdge")`

: ...- propertyDialog
`signature(object = "dg.VertexEdge")`

: ...

### Note

The `dg.Edge`

class has
beside the methods of `dg.Vertex`

the methods `oriented`

and `oriented<-`

.

The method `nodeIndicesOfEdge`

will extract the indices of the
vertices of the edge, and the method `nodeTypesOfEdge`

will
extract the types
("super classes": `vertex`

, `factor`

or `block`

)
of the vertices (nodes) of an edge.
The method `draw`

is used to draw the edge,
and items are added to the pop up menu of an edge
by the method `addToPopups`

.

Some of these methods also applies for
block edges (`dg.BlockEdge`

)
and factor edges (`dg.FactorEdge`

).

### Author(s)

Jens Henrik Badsberg

### See Also

`newVertexEdge`

,
`returnEdgeList`

,
`dg.Edge-class`

.

### Examples

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | ```
vertices <- returnVertexList(paste("V", 1:4, sep = ""))
e <- new("dg.VertexEdge", vertex.indices = c(1, 2, 3),
vertices = new("dg.VertexList", vertices[1:3]))
str(e)
color(e)
label(e)
labelPosition(e)
width(e)
oriented(e)
nodeIndicesOfEdge(e)
nodeTypesOfEdge(e)
color(e) <- "Black"
label(e) <- "1-2"
labelPosition(e) <- c(10, 20, 30)
width(e) <- 1
oriented(e) <- TRUE
nodeIndicesOfEdge(e) <- c(1, 2)
str(e)
``` |