R: Head of the edge(s) in a graph

head_of {igraph} | R Documentation

## Head of the edge(s) in a graph

### Description

For undirected graphs, head and tail is not defined. In this case `head_of` returns vertices incident to the supplied edges, and `tail_of` returns the other end(s) of the edge(s).

### Usage

    head_of(graph, es)

### Arguments

`graph` | The input graph.
`es` | The edges to query.

### Value

A vertex sequence with the head(s) of the edge(s).

### See Also

Other structural queries: `[.igraph`, `[[.igraph`, `adjacent_vertices`, `are_adjacent`, `ends`, `get.edge.ids`, `gorder`, `gsize`, `incident_edges`, `incident`, `is_directed`, `neighbors`, `tail_of`

[Package igraph version 1.2.4.1 Index]