Re: [Boost-users] [Boost][BGL] Dynamic Property, dynamic_get_failure.

Subject: Re: [Boost-users] [Boost][BGL] Dynamic Property, dynamic_get_failure.
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2011-04-26 18:15:24

On Tue, 26 Apr 2011, Mathieu - wrote:

> Hi,
>
> I'm trying to generate random graphs (with random edge weight) and
> write them to a dot file, but
> I get this exception in the write_graphviz_dp() function :
> "what():  dynamic property get cannot retrieve value for  property: weight."
>
> The code looks like this :
>
>    typedef boost::adjacency_list<boost::vecS, boost::vecS,
> boost::directedS, property<edge_index_t, int>,
> 	    			  property<edge_weight_t, int> > graph;
>
>    boost::minstd_rand gen;
>
>    graph g;
>    boost::generate_random_graph(g, 10, 30, gen, false, false);
>    boost::randomize_property<boost::edge_weight_t>(g, gen);
>
>    dynamic_properties dp;
>    dp.property("weight", get(edge_weight, g));
>
>    boost::write_graphviz_dp(std::cout, g, dp, std::string("weight"));
>
> (don't pay attention to the random generator it's just to keep it simple).
>
> I've been looking at the examples and at the doc and it doesn't seem
> to me that I'm doing something wrong... but apparently I am.

You are passing "weight" as the node_id parameter to write_graphviz_dp, 
but what you have defined as "weight" in dp is an edge property, not a 
vertex property.  I think removing the last argument to write_graphviz_dp 
should fix the problem.  Note that your adjacency_list template arguments 
also put edge_index_t as a vertex property, not an edge property like you 
probably intended.

-- Jeremiah Willcock