radial centrality layout

arranges nodes in concentric circles according to a centrality index.

layout_with_centrality(
  g,
  cent,
  scale = TRUE,
  iter = 500,
  tol = 1e-04,
  tseq = seq(0, 1, 0.2)
)

layout_igraph_centrality(
  g,
  cent,
  scale = TRUE,
  iter = 500,
  tol = 1e-04,
  tseq = seq(0, 1, 0.2),
  circular
)

Arguments

g

igraph object

cent

centrality scores

scale

logical. should centrality scores be scaled to \([0,100]\)? (Default: TRUE)

iter

number of iterations during stress optimization

tol

stopping criterion for stress optimization

tseq

numeric vector. increasing sequence of coefficients to combine regular stress and constraint stress. See details.

circular

not used

Value

matrix of xy coordinates

Details

The function optimizes a convex combination of regular stress and a constrained stress function which forces nodes to be arranged on concentric circles. The vector tseq is the sequence of parameters used for the convex combination. In iteration i of the algorithm \(tseq[i]\) is used to combine regular and constraint stress as \((1-tseq[i])*stress_{regular}+tseq[i]*stress_{constraint}\). The sequence must be increasing, start at zero and end at one. The default setting should be a good choice for most graphs.

The layout_igraph_* function should not be used directly. It is only used as an argument for plotting with 'igraph'. 'ggraph' natively supports the layout.

References

Brandes, U., & Pich, C. (2011). More flexible radial layout. Journal of Graph Algorithms and Applications, 15(1), 157-173.

Examples

library(igraph)
library(ggraph)

g <- sample_gnp(10,0.4)
if (FALSE) {
ggraph(g,layout="centrality",centrality = closeness(g))+
  draw_circle(use = "cent")+
  geom_edge_link0()+
  geom_node_point(shape = 21,fill = "grey25",size = 5)+
  theme_graph()+
  coord_fixed()
}