[Boost-users] Re: boost graph library bugs

From: Qiaofeng Yang (qyang_at_[hidden])
Date: 2004-11-01 17:10:33

Hi,

Below is a list of bugs (at least I think so) in boost graph library:

1. I used the functions illustrated in file "components_on_edgelist.cpp"
on a adjacency_list graph instead of a edge_list graph. It gave the
correct number of components in the graph, but when printing out each
components, the nodes in some of the components were disconnected. Also,
segmentation fault was flagged.(This happened when the graph had a lot of
components.)

2. I ran the source code in file "subgraph.cpp" as it was, the output was
different from the sample output given in the same file. The difference
was: the subgraph had global edge index, but local vertex index.

3. When creating multiple subgraphs, code like below would give
segmentation fault:
"
typedef property<vertex_name_t, string> VertexName;
typedef property<vertex_index_t, int, VertexName> VertexProperty;
typedef property<edge_index_t, int> EdgeProperty;
typedef subgraph< adjacency_list<vecS, vecS, undirectedS, VertexProperty,
EdgeProperty> > Graph;
...
Graph G(N);
//add edges to G
//assign names to vertices in G
...
Graph & G1 = G.creat_subgraph();
//add vertices to G1
//assign names to vertices in G1
...
"
When using function put(PropertyTag, const subgraph& g, Key k_local, const
Value& value) to assign names to the vertices of subgraph G1(it seems that
the name of vertices in G is not automatically inherited by G1.), it gave
segmentation fault. This problem would not happen if the number of
subgraphs was few such as 2.

I found the above problems when I tried to create subgraphs for each
component in the graph when the number of components was large.

Thanks for your time,
Qiaofeng