Re: [Boost-Users] BGL: "Supergraphs?"

From: David A. Greene (greened_at_[hidden])
Date: 2002-04-27 17:51:28

Jeremy Siek wrote:

> greene> I find the filtered_graph potentially very useful for my
> greene> application except for one case.  In some (not rare)
> greene> instances I need to be able to create a filtered_graph
> greene> that spans two graphs.  
> 
> It seems that the right approach would be to first have something that
> "virtually" combines the two graphs, and then simply apply filtered_graph
> to the result. However, off the top of my head I don't know of a good way
> to "virtually" combine two graphs without lots of memory overhead. I'm
> open to ideas :)

Well, no one said this would be easy.  :)  Can you comment on the
applicability of the subgraph class to this problem?  Originally I
skimmed the document and I thought that subgraph required a
consistent indexing across graphs, therefore eliminating the
possibility of using it to combine independent graphs.  However,
going over it again I read about "local" and "global" indices.
I don't think there's an interface for combining two existing graphs
into a subgraph tree (BTW the graphs in my case are truly independent
-- they do not share any nodes or vertices), but I wonder if the
subgraph _structure_ might be appropriate.  I need to look into how
that all works a little more.

                              -Dave

-- 
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  and you know how big he was."  --  James P. Johnson