Re: [boost] Re: Hypergraphs and the BGL

From: David A. Greene (greened_at_[hidden])
Date: 2002-04-27 17:41:25

> I disagree when you say this does not relate to subgraphs.  Your
> original 2 graphs are exactly that, subgraphs of this 3rd graph.

Certainly.

> Your description of what you want is what I would consider
> hierarchical graph structure: graphs can be subgraphs of other
> graphs.  What are the key problems with using BGL's 'subgraph'
> support?  

Well, for one thing the subgraphs are already created.  Some time
later I need to combine them into the "supergraph."  From the
BGL page, it looks as though the normal mode of operation is to
create the root graph first and then create subgraphs and add
vertices and edges to them.  Doing this is no less expensive
than creating a new graph out of the original separate graphs.
I don't see any interface for taking two graphs and making
a subgraph tree out of them.

> You may have already done this, but I would suggest
> examining what you could currently do with subgraphs and edge_lists
> and such operations such as unions and intersections, and decide if
> there is some limited addition to these capabilities that would
> support what you need efficiently.  I can guess it would have to
> do with on-the-fly, efficient union/intersection of
> graphs/edge_lists/vertices.

Right.

                          -Dave

-- 
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