Re: [igraph] bow tie

[Tamas Nepusz]

> is there any function in igraph to analyze and plot a graph with the
> bow-tie structure?
What do you want to analyze about it specifically? In some sense, every
directed graph can be considered a bow-tie graph:

1) Find the strongly connected components of the graph and name the largest
one as the "core". (If your graph is large enough, there will almost surely
be one core component anyway).

2) For each node not in the core, check whether it can reach the core. Name
all these nodes that are not in the core the in-component. (You can use
shortest.paths to find paths between nodes and the core).

3) For each node not in the core or the in-component, check whether they are
reachable from the core. These nodes are the out-component.

4) For all the remaining nodes, check whether they could reach the core if
you ignored edge directions (use shortest.paths with mode="all"). Nodes that
can reach the core after ignoring edge directions are parts of a tendril.

5) For all the remaining nodes, mark them as disconnected.

-- 
T.