marielle - 8 days ago 4

R Question

There is a way in R to create a hierarchical network like this?

That is, before it generates a hub of 5 nodes, to which are attached other 4 hubs, and so on until you get the general network.

I think I can use the

`make_tree`

This is what I did.

`net <- make_tree(n = 5, children = 4, mode = "undirected")`

plot(net)

Thank you

Answer

Not sure how elegant this is. It would take more work to get the plot to look like yours but I *think* the graph is correct.

```
library(igraph)
#' This adds the gadd graph to the main graph, g, and wires all of its vertices
#' to the central vertex of g
attach_to_center <- function(g, gadd) {
g <- g + gadd + edges(as.vector(rbind(1, gorder(g) + 1:gorder(gadd))))
}
nIter <- 2
nChild <- 4
# The initial graph
g <- make_empty_graph(5, directed = FALSE) + edges(1,2,1,3,1,4,1,5,2,3,3,4,4,5,5,2)
for (j in 1:nIter) {
g0 <- g
for (i in 1:nChild) {
g <- attach_to_center(g, g0)
}
}
plot(g, vertex.label = NA)
```

It seems quick enough (although plotting gets out of hand for more than 3 or 4 iterations).

Source (Stackoverflow)