On Tue, Mar 17, 2009 at 11:42 AM, Andrew Sutton wrote:

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I would guess it's working for me by accident since I'm never removing anything from the graphs I create.  I'll make sure to keep my usage to listS for now.

Be forewarned: num_edges()/num_vertices() with listS is O(n).

So what's the recommendation? The Known Bugs page says that anything other than listS is not guaranteed to work for EdgeList, but if std::list has O(n) size(), then num_edges()/num_vertices() becomes O(n)? Or were you talking about OutEdgeList? Are there *known* cases where vecS is bug-free when used for the EdgeList? In my case, I know the total number of edges ahead of time, and no edges or vertices will ever be removed. --Michael Fawcett

On Tue, Mar 17, 2009 at 11:56 AM, Andrew Sutton wrote:

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So what's the recommendation?  The Known Bugs page says that anything other than listS is not guaranteed to work for EdgeList, but if std::list has O(n) size(), then num_edges()/num_vertices() becomes O(n)?

Or were you talking about OutEdgeList?

Both. Any selector of listS will cause corresponding functions that use size() to be linear. I'm just giving a reminder since it's bitten me before :)

I'll keep that in mind, thanks.

On a side note, there are two new graph classes in trunk ([un]directed_graph) that wrap listS selected adjacency lisst and provide O(1) num_* and *degree functions. They also provide builtin index maps and functinality for renumbering vertices/edges. They aren't really documented yet and certainly won't be part of the release for a while.

Looking forward to this. We subclassed adjacency_list and made our own undirected_graph, but I'd like to stop using it and use yours.

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Are there *known* cases where vecS is bug-free when used for the EdgeList?  In my case, I know the total number of edges ahead of time, and no edges or vertices will ever be removed.

I think the general rule is that if you don't need to remove anything, you can use vecS wherever you want. It's the removals that really kill the adjacency list.

Luckily our graphs are immutable, so I'll continue to use vecS for OutEdgeList and start using it for EdgeList as well. Thanks, --Michael Fawcett P.S. sorry for the subject line mess up.

I need to convert any bidirectional graph into an adjacency_list, but looks like the copy constructor cannot handle it (needs the same type in input). I don't see any simple way to convert any directed graph into an adjacency_list. Is there any more-or-less-simple way to do it that I don't know? May be there is a way to copy graphs constrained not by the concrete type of the graph, but only, may be, on graph concepts? Thanks,

There's no direct conversion between *any* bidirectional graph and a directed adjancency_list. If you're talking about any bidirectional adjacency list and a directed one, you shouldn't actually need to convert them. As an alternative, you could use copy_graph. Andrew Sutton andrew.n.sutton@gmail.com