> For a directed graph, I found though that
> graphviz either doesn't handle more than a few dozen states or creates
> an incomprehensible entangled mess (with its fast layout algorithm).
400 nodes here:
Finding a good representation for a large graph is challenging
and needs more studies.
But they have technics to order the nodes or explore them
just like "the fish eye view".
And those softwares deserve to be thought of.