`R/layout_igraph.R`

`layout_tbl_graph_igraph.Rd`

This layout function makes it easy to apply one of the layout algorithms
supplied in igraph when plotting with ggraph. Layout names are auto completed
so there is no need to write `layout_with_graphopt`

or
`layout_as_tree`

, just `graphopt`

and `tree`

(though the
former will also work if you want to be super explicit). Circular layout is
only supported for tree-like layout (`tree`

and `sugiyama`

) and
will throw an error when applied to other layouts.

```
layout_tbl_graph_igraph(
graph,
algorithm,
circular,
offset = pi/2,
use.dummy = FALSE,
...
)
```

- graph
A

`tbl_graph`

object.- algorithm
The type of layout algorithm to apply. See

*Details*or`igraph::layout_()`

for links to the layouts supplied by igraph.- circular
Logical. Should the layout be transformed to a circular representation. Defaults to

`FALSE`

. Only applicable to`algorithm = 'tree'`

and`algorithm = 'sugiyama'`

.- offset
If

`circular = TRUE`

, where should it begin. Defaults to`pi/2`

which is equivalent to 12 o'clock.- use.dummy
Logical. In the case of

`algorithm = 'sugiyama'`

should the dummy-infused graph be used rather than the original. Defaults to`FALSE`

.- ...
Arguments passed on to the respective layout functions

A data.frame with the columns `x`

, `y`

, `circular`

as
well as any information stored as node variables in the tbl_graph object.

igraph provides a huge amount of possible layouts. They are all briefly described below:

**Hierarchical layouts**

`tree`

Uses the

*Reingold-Tilford*algorithm to place the nodes below their parent with the parent centered above its children. See`igraph::as_tree()`

`sugiyama`

Designed for directed acyclic graphs (that is, hierarchies where multiple parents are allowed) it minimizes the number of crossing edges. See

`igraph::with_sugiyama()`

**Standard layouts**

`bipartite`

Minimize edge-crossings in a simple two-row (or column) layout for bipartite graphs. See

`igraph::as_bipartite()`

`star`

Place one node in the center and the rest equidistantly around it. See

`igraph::as_star()`

`circle`

Place nodes in a circle in the order of their index. Consider using

`layout_tbl_graph_linear()`

with`circular=TRUE`

for more control. See`igraph::in_circle()`

`nicely`

Tries to pick an appropriate layout. See

`igraph::nicely()`

for a description of the simple decision tree it uses`dh`

Uses

*Davidson and Harels*simulated annealing algorithm to place nodes. See`igraph::with_dh()`

`gem`

Place nodes on the plane using the GEM force-directed layout algorithm. See

`igraph::with_gem()`

`graphopt`

Uses the Graphopt algorithm based on alternating attraction and repulsion to place nodes. See

`igraph::with_graphopt()`

`grid`

Place nodes on a rectangular grid. See

`igraph::on_grid()`

`mds`

Perform a multidimensional scaling of nodes using either the shortest path or a user supplied distance. See

`igraph::with_mds()`

`sphere`

Place nodes uniformly on a sphere - less relevant for 2D visualizations of networks. See

`igraph::on_sphere()`

`randomly`

Places nodes uniformly random. See

`igraph::randomly()`

`fr`

Places nodes according to the force-directed algorithm of Fruchterman and Reingold. See

`igraph::with_fr()`

`kk`

Uses the spring-based algorithm by Kamada and Kawai to place nodes. See

`igraph::with_kk()`

`drl`

Uses the force directed algorithm from the DrL toolbox to place nodes. See

`igraph::with_drl()`

`lgl`

Uses the algorithm from Large Graph Layout to place nodes. See

`igraph::with_lgl()`

This function is not intended to be used directly but by setting
`layout = 'igraph'`

in `create_layout()`

Other layout_tbl_graph_*:
`layout_tbl_graph_auto()`

,
`layout_tbl_graph_backbone()`

,
`layout_tbl_graph_centrality()`

,
`layout_tbl_graph_circlepack()`

,
`layout_tbl_graph_dendrogram()`

,
`layout_tbl_graph_eigen()`

,
`layout_tbl_graph_fabric()`

,
`layout_tbl_graph_focus()`

,
`layout_tbl_graph_hive()`

,
`layout_tbl_graph_linear()`

,
`layout_tbl_graph_manual()`

,
`layout_tbl_graph_matrix()`

,
`layout_tbl_graph_partition()`

,
`layout_tbl_graph_pmds()`

,
`layout_tbl_graph_stress()`

,
`layout_tbl_graph_treemap()`

,
`layout_tbl_graph_unrooted()`