# Eigenvalues and eigenvectors of the adjacency matrix of a graph

Source:`R/centrality.R`

`graph.eigen.Rd`

`graph.eigen()`

was renamed to `spectrum()`

to create a more
consistent API.

## Usage

```
graph.eigen(
graph,
algorithm = c("arpack", "auto", "lapack", "comp_auto", "comp_lapack", "comp_arpack"),
which = list(),
options = arpack_defaults()
)
```

## Arguments

- graph
The input graph, can be directed or undirected.

- algorithm
The algorithm to use. Currently only

`arpack`

is implemented, which uses the ARPACK solver. See also`arpack()`

.- which
A list to specify which eigenvalues and eigenvectors to calculate. By default the leading (i.e. largest magnitude) eigenvalue and the corresponding eigenvector is calculated.

- options
Options for the ARPACK solver. See

`arpack_defaults()`

.