Re: [Boost-users] [boost::graph] creating an external map for depth_first_search

From: Aaron Windsor (aaron.windsor_at_[hidden])
Date: 2007-10-02 07:42:41

On 10/1/07, v r <soth1985_at_[hidden]> wrote:
> I cannot figure out how to create a color map for depth first search, i`m
> using bundled properties and the following type as graph.
> adjacency_list<listS,setS,bidirectionalS,WorldNode> world_graph_t;
>
> right now i`m trying to make it like this, but i get 50 errors and cannot
> deduce what my error is.
>
> template<class VisitorT>
> THOR_INLINE void DepthFirstSearch(const VisitorT& vis, const
> vertex_descriptor& start)
> {
> using namespace boost;
> std::vector<default_color_type> color_vec( num_vertices(graph) );
> depth_first_search(graph, visitor(vis),
> color_map(make_iterator_property_map(color_vec.begin(),get(vertex_color,graph))),
> start);
> }

Hi,

>From the depth_first_search documentation: The type ColorMap must be a
model of Read/Write Property Map and its key type must be the graph's
vertex descriptor type and the value type of the color map must model
ColorValue. Based on the definition of color_vec and the code you've
written above, this would mean that vertex_color would have to be an
interior property mapping each vertex desciptor to a distinct integer
in the range [0..num_vertices(graph)). But your graph declaration
doesn't include any interior property declarations. I'm assuming that
WorldNode is a struct that contains a vertex_color member? Then you
really want to say "get(&WorldNode::vertex_color, graph)" instead of
"get(vertex_color,graph)". You also need to initialize
WorldNode::vertex_color with the appropriate integer range for all
vertices in the graph.

That's my best guess without seeing any of the error messages or the
definition of WorldNode.

Regards,
Aaron