I have a directed graph that has the following structure: Each node "i" has a parameter N_i associated with it. There is a vertex from "i" to "j" only if N_i < N_j. So it's clear that in this graph there is a hierarchical structure and I was wondering what is the best way for representing this kind of graph. I tried using the hierachical layout but it seems that doesn't respect the natural order that the nodes have (that one given by the parameter N_x). The ideal would be having a vertical representation of the graph in which the y coordinate of the nodes respect the order given by the parameter N_i and in which the x coordinate of each node would be so that to minimize the intersection of the edges (so that an application of the edge bundling algorithm would be even more efficient).
Thanks a lot,
You are right hierarchical algorithm are exactly what you need.
in tulip you can use the tulip hierachical algorithm
use these parameters (if your nodes have got a size of (1,1,1);
node size (viewsize)
layer spacing 2
node spacing 2
else you can also use the ogdf sugyama algorithm (look in the plugin server).
PS: the aspect ratio of hierachical layout are often really bad use the option Force ratio in the menu->option
to re scale automatically your layout.
If tulip doesn't fit your needs dot from Graphviz do a really good job on that kind of graphs. (you can re-import the generated dot file in tulip after if you want :) )
Thanks a lot for the hints.