Re: [Boost-users] [BGL] visitors.hpp:138: error: no type named 'event_filter' in 'class dijkstra_custom_visitor'

Subject: Re: [Boost-users] [BGL] visitors.hpp:138: error: no type named 'event_filter' in 'class dijkstra_custom_visitor'
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2013-11-22 11:00:25

On Fri, 22 Nov 2013, The Maschine wrote:

> Hi,
> My code is very simple so I suspect I missing something about the real 'examine_vertex' meaning.
> 
> One example with the custom visitor and one without that produces the correct results out site the 'search' (I;d like to be able to do it with a visitor
> though for later steps) Simplified to just the essentials.
> 
> #### With VISITOR ####
> 
>             IndexMap indexMap = boost::get(boost::vertex_index, m_ugraph);
>             PredecessorMap predecessorMap(&predecessors[0], indexMap);
>             DistanceMap distanceMap(&distances[0], indexMap);
> 
>             glm::dvec3 s_mid = m_ugraph[*vertex_iterator_begin].m_mid_point;
>             double thres = 500.0f;
>             dijkstra_threshold vis(s_mid,thres);
> 
>             try {
>                 boost::dijkstra_shortest_paths(m_ugraph, *vertex_iterator_begin,
> boost::predecessor_map(predecessorMap).distance_map(distanceMap).visitor(vis));
>             } catch (...) { }
> 
>             int total_node_count2 = 0;
>             double total_depth2 = 0.0;
>             for (boost::tie(vi, vi_end) = boost::vertices(m_ugraph); vi != vi_end; ++vi) {
> 
>                 if( (double(distances[*vi])*1.1) >= std::numeric_limits<double>::max() || (std::isnan(distances[*vi])) ||
> !(std::isfinite(distances[*vi])) ) {
> 
>                 } else {
>                         total_depth2 += double(distances[*vi]);
>                         total_node_count2 += 1;
>                 }
>             }
> 
> ####
> To the total distances and the number of nodes within the radius is not correct…
> 
> #### Without a visitor outside dijkstra_shortest_paths ####
> 
>            try {
>                 boost::dijkstra_shortest_paths(m_ugraph, *vertex_iterator_begin, boost::predecessor_map(predecessorMap).distance_map(distanceMap));
>             } catch (...) { }
> 
>             int total_node_count2 = 0;
>             double total_depth2 = 0.0;
>             for (boost::tie(vi, vi_end) = boost::vertices(m_ugraph); vi != vi_end; ++vi) {
> 
>                 if( (double(distances[*vi])*1.1) >= std::numeric_limits<double>::max() || (std::isnan(distances[*vi])) ||
> !(std::isfinite(distances[*vi])) ) {
>                 } else {
>                     if( thres > 0.0f && glm::distance(s_mid, m_ugraph[*vi].m_mid_point) < thres ) {
>                         total_depth2 += double(distances[*vi]);
>                         total_node_count2 += 1;
>                 }
>             }
> 
> ###
> This give you the correct results but you searched the full graph.

What are you using as your weight map?  I don't see one in the listing. 
Does it match what glm::distance returns?  Can you please check (with the 
non-early-exit version) whether the distances in examine_vertex are 
monotonic (try using both the distance map and glm::distance)?

-- Jeremiah Willcock