Bulent Nedim Alemdar wrote:

Hi

I am a very fresh user of Boost library. While I was searching the internet for a bandwidth optimization algorithm, I found Boost Graph Library.

The library supports an RCM algorithm (cuthill_mckee_ordering) and I have checked the example given at this address: http://www.boost.org/libs/graph/example/cuthill_mckee_ordering.cpp

It seems like the used vertex numbers given in this example is sequential and starts form 0: vertex list: 0, 1, 2, 3, 4, 5, 6, 7,8, 9 and a edge list is constructed from these vertex numbers.

Do I have to define such a sequential order and always start from 0?

I'm not a BGL pro either, but I think that the sequential order is mandatory. If you just need other labels than those given by the sequential order, you can define an internal map, like here: typedef boost::adjacency_list< boost::vecS, //edges boost::vecS, //nodes boost::undirectedS, //vertex properties boost::property<boost::vertex_name_t, std::int> //your custom label // no edge properties > Graph; You can access the map as follows: Graph g(10); typedef boost::property_map<Graph, boost::vertex_name_t>::type Graph_namemap_t; Graph_namemap_t namemap = get(boost::vertex_name,g); This gives you a map of BGLnodes to your label; I don't know if this is enough for you, because adding edges still requires to use the BGL nodes. Note: Adding an internal property to your graph changes the type of BGLnodes from int to an other type. Hope this is at least a bit helpful. Martin

What if I define vertex numbers such as : 1, 6, 9, 10, 11, 13, 21, 25, 26, 30, and define a valid edge like: ( 1,10), (1,13), (6,21), (6,30), (6,11), (6,9), (10,13), (10,26), (10,9), (13,21), (21,25), (9,11), (13,35)

The above vertex list is a relabed list of the one given in the example code and I defined the same edge (connectivity) list.

In fact, I tried it but the returned ordered list is not valid. Unless I use the vertex numbers starting from 0 and goes up to 9 like given on the example, the returned ordered is wrong.

I really appreciate your comments and helps on this

thanks bulent

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-- ----------------------------------------------------------------------------- Martin Okrslar MPI for Molecular Genetics phone: ++ 49 + 30 / 8413-1166 Computational Molecular Biology Fax: ++ 49 + 30 / 8413-1152 Ihnestrasse 73 email: okrslar@molgen.mpg.de D-14195 Berlin URL: http://cmb.molgen.mpg.de -----------------------------------------------------------------------------