January 2015 - Boost-users - lists.preview.boost.org

How to implement overloading functions using boost concepts?
by Neuton de Oliveira Braga Júnior 07 Jan '15

07 Jan '15

Hi, I would like to have overloading functions such that they are dispatched with boost concepts. See minimal example below: #include <iostream> #include <boost/concept/usage.hpp> #include <boost/concept/requires.hpp> template<class T> struct XConcept { BOOST_CONCEPT_USAGE(XConcept) { int x = t.x; } private: T t; }; template<class T> struct XYConcept : XConcept<T> { … [View More]

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[Graph] [BGL] trying to modify brandes betweenness impl
by The Maschine 06 Jan '15

06 Jan '15

Hello all and happy new year! Im trying to modify the brandes centrality in order to analyse only a subset of the graph based on a cutoff distance calculated by some other edge weight than the one used for the brandes call. What I have done so far is to add a shortest path search call before the main path search inside brandes_betweenness_centrality_impl. The first search uses the edge::m_metric_weight and constructs the distance map from 's' based on that weight. Then I feed the metric … [View More]distance map in the 'brandes special visitor' and I check inside visitor's examine_vertex. Reminder that the brandes call uses the m_special_weight. While this works as a principle I have no idea how people with experience would do it! A problem with this is that while the metric cutoff can be small you still run both searches to the max (as if there is no cutoff). Any help on how to change the first 'dijkstra_shortest_paths' so that after reaching the cutoff the search stops gracefully and leaves the rest of the 'distance_map' to infinity? Thanks a lot and please let me know if something need more clarification. ############### struct EdgeProperties { double m_special_weight; double m_metric_distance_weight; }; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, VertexProperties, EdgeProperties> unGraph; // test my_brandes_dijkstra_visitor // template<typename Graph, typename WeightMap, typename IncomingMap, typename DistanceMap, typename PathCountMap> struct my_brandes_dijkstra_visitor : public bfs_visitor<> { typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef typename graph_traits<Graph>::edge_descriptor edge_descriptor; my_brandes_dijkstra_visitor(std::stack<vertex_descriptor>& iordered_vertices, WeightMap iweight, IncomingMap iincoming, DistanceMap idistance, PathCountMap ipath_count, std::vector<float> c_dists, float coff) : ordered_vertices(iordered_vertices), weight(iweight), incoming(iincoming), distance(idistance), path_count(ipath_count), cutoff_dists(c_dists), cutoff(coff) { } /** * Whenever an edge e = (v, w) is relaxed, the incoming edge list * for w is set to {(v, w)} and the shortest path count of w is set to * the number of paths that reach {v}. */ void edge_relaxed(edge_descriptor e, const Graph& g) { vertex_descriptor v = source(e, g), w = target(e, g); incoming[w].clear(); incoming[w].push_back(e); put(path_count, w, get(path_count, v)); } /** * If an edge e = (v, w) was not relaxed, it may still be the case * that we've found more equally-short paths, so include {(v, w)} in the * incoming edges of w and add all of the shortest paths to v to the * shortest path count of w. */ void edge_not_relaxed(edge_descriptor e, const Graph& g) { typedef typename property_traits<WeightMap>::value_type weight_type; typedef typename property_traits<DistanceMap>::value_type distance_type; vertex_descriptor v = source(e, g), w = target(e, g); distance_type d_v = get(distance, v), d_w = get(distance, w); weight_type w_e = get(weight, e); closed_plus<distance_type> combine; if (d_w == combine(d_v, w_e)) { put(path_count, w, get(path_count, w) + get(path_count, v)); incoming[w].push_back(e); } } /// Keep track of vertices as they are reached void examine_vertex(vertex_descriptor w, const Graph&) { // add only if this is within the 'cutoff'. cutoff_dists holds // the metric distances from s. if( cutoff_dists[w] < cutoff ) ordered_vertices.push(w); } private: std::stack<vertex_descriptor>& ordered_vertices; WeightMap weight; IncomingMap incoming; DistanceMap distance; PathCountMap path_count; std::vector<float> cutoff_dists; float cutoff; }; //////////////////////////////////////////////////////////////////// template<typename WeightMap> struct my_brandes_dijkstra_shortest_paths { my_brandes_dijkstra_shortest_paths(WeightMap iweight_map) : weight_map(iweight_map) { } template<typename Graph, typename IncomingMap, typename DistanceMap, typename PathCountMap, typename VertexIndexMap> void operator()(Graph& g, typename graph_traits<Graph>::vertex_descriptor s, std::stack<typename graph_traits<Graph>::vertex_descriptor>& ov, IncomingMap incoming, DistanceMap distance, PathCountMap path_count, VertexIndexMap vertex_index , std::vector<float> c_dists, float coff) // modified cutoff vector and value { typedef my_brandes_dijkstra_visitor<Graph, WeightMap, IncomingMap, DistanceMap, PathCountMap> visitor_type; visitor_type visitor(ov, weight_map, incoming, distance, path_count,c_dists,coff); // modified cutoff vector and value dijkstra_shortest_paths(g, s, boost::weight_map(weight_map) .vertex_index_map(vertex_index) .distance_map(distance) .visitor(visitor)); } private: WeightMap weight_map; }; ////////////////////////////// template<typename Graph, typename CentralityMap, typename EdgeCentralityMap, typename IncomingMap, typename DistanceMap, typename DependencyMap, typename PathCountMap, typename VertexIndexMap, typename ShortestPaths> void my_brandes_betweenness_centrality_impl(const Graph& g, CentralityMap centrality, // C_B EdgeCentralityMap edge_centrality_map, IncomingMap, //incoming, // P // OpenMP mod DistanceMap, //distance,// d // OpenMP mod DependencyMap, //dependency,// delta // OpenMP mod PathCountMap, //path_count,// sigma // OpenMP mod VertexIndexMap vertex_index, ShortestPaths shortest_paths) { typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator; typedef typename graph_traits<Graph>::edge_iterator edge_iterator; typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; // Initialize centrality init_centrality_map(vertices(g), centrality); init_centrality_map(edges(g), edge_centrality_map); int i, N = num_vertices(g); #pragma omp parallel for default(shared) private(i) schedule(dynamic) for (i = 0; i < N; ++i) { typename graph_traits<Graph>::vertex_descriptor s = vertex(i, g); if (s == graph_traits<Graph>::null_vertex()) continue; // First we build a map of all distances from 's' based // on m_metric_distance_weight. typedef typename boost::property_map < Graph, boost::vertex_index_t >::type CIndexMap; typedef typename boost::iterator_property_map < vertex_descriptor*, CIndexMap, vertex_descriptor, vertex_descriptor& > CPredecessorMap; typedef typename boost::iterator_property_map < float*, CIndexMap, float, float& > CDistanceMap; float co = 2200.0f; std::vector<vertex_descriptor> cut_predecessors(boost::num_vertices(g)); // To store parents std::vector<float> cut_distances(boost::num_vertices(g), std::numeric_limits<double>::max() ); // To store distances CIndexMap cut_indexMap = boost::get(boost::vertex_index, g); CPredecessorMap cut_predecessorMap(&cut_predecessors[0], cut_indexMap); CDistanceMap cut_distanceMap(&cut_distances[0], cut_indexMap); // boost::dijkstra_shortest_paths(g, s, boost::weight_map(get(&EdgeProperties::m_metric_distance_weight, g)).predecessor_map(cut_predecessorMap).distance_map(cut_distanceMap)); /////////// // Local storage for OpenMP std::stack<vertex_descriptor> ordered_vertices; vector_property_map<typename property_traits<IncomingMap>:: value_type,VertexIndexMap> incoming(vertex_index); vector_property_map<typename property_traits<DistanceMap>:: value_type,VertexIndexMap> distance(vertex_index); vector_property_map<typename property_traits<DependencyMap>:: value_type,VertexIndexMap> dependency(vertex_index); vector_property_map<typename property_traits<PathCountMap>:: value_type,VertexIndexMap> path_count(vertex_index); // Initialize for this iteration vertex_iterator w, w_end; for (tie(w, w_end) = vertices(g); w != w_end; ++w) { incoming[*w].clear(); put(path_count, *w, 0); put(dependency, *w, 0); } put(path_count, s, 1); // co - cutoff added. b_centrality is calculated based on // Edge::m_special_weight while we are testing // to be inside the 'cutoff' that is based on the // Edge::m_metric_weight. shortest_paths(g, s, ordered_vertices, incoming, distance, path_count, vertex_index, cut_distances, co); while (!ordered_vertices.empty()) { vertex_descriptor u = ordered_vertices.top(); ordered_vertices.pop(); typedef typename property_traits<IncomingMap>::value_type incoming_type; typedef typename incoming_type::iterator incoming_iterator; typedef typename property_traits<DependencyMap>::value_type dependency_type; for (incoming_iterator vw = incoming[u].begin(); vw != incoming[u].end(); ++vw) { vertex_descriptor v = source(*vw, g); dependency_type factor = dependency_type(get(path_count, v)) / dependency_type(get(path_count, u)); factor *= (dependency_type(1) + get(dependency, u)); put(dependency, v, get(dependency, v) + factor); update_centrality(edge_centrality_map, *vw, factor); } if (u != s) { #pragma omp critical(globalupdate) { update_centrality(centrality, u, get(dependency, u)); } } } } typedef typename graph_traits<Graph>::directed_category directed_category; const bool is_undirected = is_convertible<directed_category*, undirected_tag*>::value; if (is_undirected) { divide_centrality_by_two(vertices(g), centrality); divide_centrality_by_two(edges(g), edge_centrality_map); } } // [View Less]

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pass asio socket to another class
by cap 05 Jan '15

05 Jan '15

I have two classes SslHandshake and SslRequest with according to names functionality. After client and server handshakes are done in the SslHandshake, I pass both sockets to SslRequest and start transferring data from server to client. 1. If I is not waiting for finishing of transferring, instance of SslHandshake will be destroyed automatically (in the ~SslHandshake I will destroy both socket objects and transferring in the SslRequest will be aborted). 2. If I start transferring with waiting, … [View More]after a few iterations SslRequest::ReadSocketOut will be called successfully, but the readSocketHandle will not be called (so, will be called but with timeout error). So, I need to handshake in one class and transfer data into another class. How to prevent destroying instance of SslHandshake until data transferring will be done into SslRequest or how to fix socket reading without callback calling after a few iterations? void SslHandshake::HandshakeInHandle(const bSystem::error_code &error) { TRY { CHECK_BOOST_ERROR { LOG_MSG_DEBUG_KEYWORD(KEYWORD_INCOMING, << "Handshake done"); // --- Transfer with waiting of mutex //IoServicePtr servicePointer((IoService *)&m_SocketIn->get_io_service()); //boost::thread serviceThread(boost::bind(&IoService::IO_SERVICE_THREAD_VOID, servicePointer)); //SslRequest::SharedPtr sslRequest(new SslRequest(m_SocketIn, m_SocketOut)); //sslRequest->Transfer(); SslRequest::SocketPtr socketIn(m_SocketIn); SslRequest::SocketPtr socketOut(m_SocketOut); // --- Transfer with waiting of thread //IoServicePtr servicePointer((IoService *)&m_SocketIn->get_io_service()); //servicePointer->SessionIndex = IndexThis; //boost::thread serviceThread(boost::bind(&IoService::IO_SERVICE_THREAD_VOID, servicePointer)); //SslRequest::SharedPtr request = SslRequest::CreateInstance(m_SocketIn, m_SocketOut); //request->Transfer(); //serviceThread.join(); // --- Transfer with waiting of IO_SERVICE_THREAD_VOID IoServicePtr servicePointer((IoService *)&m_SocketIn->get_io_service()); servicePointer->SessionIndex = IndexThis; SslRequest::SharedPtr request = SslRequest::CreateInstance(/*m_SocketIn, m_SocketOut*/socketIn, socketOut INDEX_THIS_PASS); request->Transfer(); servicePointer->IO_SERVICE_THREAD_VOID(); } } CATCH_LOG_STD CATCH_LOG_ANY } void SslRequest::ReadSocketOut(TransferringBuffer &buffer, SimpleSocketCallback readSocketHandle) { bAsIO::async_read( *m_SocketOut, bAsIO::buffer(buffer), boost::bind( readSocketHandle, SHARED_FROM_THIS, baPlaceholders::error, baPlaceholders::bytes_transferred)); } -- View this message in context: http://boost.2283326.n4.nabble.com/pass-asio-socket-to-another-class-tp4670… Sent from the Boost - Users mailing list archive at Nabble.com. [View Less]

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Boost.DateTime library to synthesise time-series data?
by Riskybiz 05 Jan '15

05 Jan '15

Dear boost-users, It's my first time trying this and hope that someone may be able to enlighten me about which aspects of the Boost.DateTime library will help solve this problem... I have some time-series data which is time stamped with boost::posix_time::ptime values. From this base-series I would like to synthesise higher interval time-series. For example, a base-series of 1 second time-series data could be used to synthesise a time-series of any greater interval; 2 seconds, 5 … [View More]

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How to build Boost with VC++ 2013 to target XP/2003 platform?
by Caroline Beltran 01 Jan '15

01 Jan '15

Programs written in VC++ 2012 or 2013 will only run on Windows XP or Windows 2003 when you choose the 'Windows XP (v120_xp)' toolset option in the IDE. Is there some way to set this option from Bjam? P.S. A Stack Overflow user indicated that he got Boost to build under VC++ 2012. I tried his solution under VC++ 2013 but it did not work for some reason completely unknown to me. http://stackoverflow.com/questions/27695187/modify-visual-c-vcvars32-bat-to… Apparently, VC++ 2012/2013 use the … [View More]

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[boost] [compute] Review results
by Antony Polukhin 01 Jan '15

01 Jan '15

Hi all, Extended review period for Boost.Compute library has ended. Here are the review votes for inclusion (+ means include, - means do not include, +/- means conditional include or "probably include, not quite sure"): + Denis Demidov + Sebastian Schaetz + Pavan Yalamanchili - Gruenke,Matt (+ if more backends will be supported) + Asbjørn (mini-review/comments from a library user) + Thomas M (a lot of suggestions) + Paul A. Bristow + Belcourt, Kenneth + John Bytheway +/- Yiannis Papadopoulos (… [View More]

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