Graphviz: break flat but sparsely connected graph into multiple rows?

Question

Howto break a flat but sparsely connected graphviz graph into multiple rows?

Graphviz yields a graph of about 4 ranks, but over 9000 nodes wide. However since the graph is sparsely connected we could break it in to rows, for example each 1000 nodes, and thus make it fit on nine rows one page. How can this be done?

Not looking for unflatten, but rather something like line breaks in a text editor (is it clear what I am looking for?).

Edit: PDF with example graph here

Answer 1

Like GraphViz Documentation, section 2.5: Node and Edge Placement, like Figure 9: Graph with constrained ranks?

http://www.graphviz.org/pdf/dotguide.pdf

Answer 2

I found a work around: we take the output of running the dot command (which is a dot file with all x/y positions in there) and pipe it through a ruby script to break the graph into lines "manually".