無法在Kamada-Kawai布局中使用整數邊緣權重

Question

這個問題從這里開始，但是在所有更新之后，它已經是另一個具有不同標題的問題。

我的Graph類型定義如下：

using Graph = boost::adjacency_list<vecS, setS, undirectedS, State, CostType>;

其中CostType恰好是int 。

我正在嘗試獲取Kamada-Kawai的春季布置，如下所示：

template <class PointMap>
PointMap layout() const {
    PointMap res;
    boost::associative_property_map<PointMap> temp(res);
    circle_graph_layout(g_, temp, 10.0);

    // https://stackoverflow.com/q/33903879/2725810
    // https://stackoverflow.com/a/8555715/2725810
    typedef std::map<VertexDescriptor, std::size_t> IndexMap;
    IndexMap mapIndex;
    associative_property_map<IndexMap> propmapIndex(mapIndex);

    // http://www.boost.org/doc/libs/1_59_0/libs/graph/doc/bundles.html
    kamada_kawai_spring_layout(g_, temp, get(edge_bundle, g_),
                               square_topology<>(50.0), side_length(50.0),
                               layout_tolerance<CostType>(),
                               CostType(1), propmapIndex);
    return res;
} 

gcc版本4.8.2抱怨：

In file included from Graph.h:13:0,
                 from Astar.h:5,
                 from Test.cpp:4:
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp: In instantiation of ‘bool boost::detail::graph::kamada_kawai_spring_layout_impl<Topology, Graph, PositionMap, WeightMap, EdgeOrSideLength, Done, VertexIndexMap, DistanceMatrix, SpringStrengthMatrix, PartialDerivativeMap>::run() [with Topology = boost::square_topology<>; Graph = boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>; PositionMap = boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >; WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>; EdgeOrSideLength = boost::detail::graph::edge_or_side<false, double>; Done = boost::layout_tolerance<int>; VertexIndexMap = boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >; DistanceMatrix = __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >; SpringStrengthMatrix = __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >; PartialDerivativeMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::convex_topology<2ul>::point_difference*, std::vector<boost::convex_topology<2ul>::point_difference, std::allocator<boost::convex_topology<2ul>::point_difference> > >, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, boost::convex_topology<2ul>::point_difference, boost::convex_topology<2ul>::point_difference&>]’:
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:524:20:   required from ‘bool boost::kamada_kawai_spring_layout(const Graph&, PositionMap, WeightMap, const Topology&, boost::detail::graph::edge_or_side<EdgeOrSideLength, T>, Done, typename boost::property_traits<DistanceMap>::value_type, VertexIndexMap, DistanceMatrix, SpringStrengthMatrix, PartialDerivativeMap) [with Topology = boost::square_topology<>; Graph = boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>; PositionMap = boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >; WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>; T = double; bool EdgeOrSideLength = false; Done = boost::layout_tolerance<int>; VertexIndexMap = boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >; DistanceMatrix = __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >; SpringStrengthMatrix = __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >; PartialDerivativeMap = boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::convex_topology<2ul>::point_difference*, std::vector<boost::convex_topology<2ul>::point_difference, std::allocator<boost::convex_topology<2ul>::point_difference> > >, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, boost::convex_topology<2ul>::point_difference, boost::convex_topology<2ul>::point_difference&>; typename boost::property_traits<DistanceMap>::value_type = int]’
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:559:79:   required from ‘bool boost::kamada_kawai_spring_layout(const Graph&, PositionMap, WeightMap, const Topology&, boost::detail::graph::edge_or_side<EdgeOrSideLength, T>, Done, typename boost::property_traits<DistanceMap>::value_type, VertexIndexMap) [with Topology = boost::square_topology<>; Graph = boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>; PositionMap = boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >; WeightMap = boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>; T = double; bool EdgeOrSideLength = false; Done = boost::layout_tolerance<int>; VertexIndexMap = boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >; typename boost::property_traits<DistanceMap>::value_type = int]’
Graph.h:112:61:   required from ‘PointMap StateGraph<StateNeighbor>::layout() const [with PointMap = std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > >; StateNeighbor = StateNeighbor<Pancake>]’
Drawer.h:60:75:   required from ‘Drawer<Graph>::Drawer(const Graph&) [with Graph = StateGraph<StateNeighbor<Pancake> >]’
Test.cpp:34:22:   required from here
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:313:96: error: no matching function for call to ‘boost::detail::graph::linear_solver<2ul>::solve(boost::detail::graph::kamada_kawai_spring_layout_impl<boost::square_topology<>, boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>, boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >, boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>, boost::detail::graph::edge_or_side<false, double>, boost::layout_tolerance<int>, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::convex_topology<2ul>::point_difference*, std::vector<boost::convex_topology<2ul>::point_difference, std::allocator<boost::convex_topology<2ul>::point_difference> > >, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, boost::convex_topology<2ul>::point_difference, boost::convex_topology<2ul>::point_difference&> >::weight_type [2][2], boost::detail::graph::kamada_kawai_spring_layout_impl<boost::square_topology<>, boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>, boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >, boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>, boost::detail::graph::edge_or_side<false, double>, boost::layout_tolerance<int>, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::convex_topology<2ul>::point_difference*, std::vector<boost::convex_topology<2ul>::point_difference, std::allocator<boost::convex_topology<2ul>::point_difference> > >, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, boost::convex_topology<2ul>::point_difference, boost::convex_topology<2ul>::point_difference&> >::deriv_type&)’
 _difference_type delta = -linear_solver<Point::dimensions>::solve(dE_d_d, dE_d);
                                                                               ^
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:313:96: note: candidate is:
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:95:18: note: template<class Vec> static Vec boost::detail::graph::linear_solver<2ul>::solve(double (*)[2], Vec)
       static Vec solve(double mat[2][2], Vec rhs) {
                  ^
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:95:18: note:   template argument deduction/substitution failed:
/home/meir/boost_1_59_0/boost/graph/kamada_kawai_spring_layout.hpp:313:96: note:   cannot convert ‘dE_d_d’ (type ‘boost::detail::graph::kamada_kawai_spring_layout_impl<boost::square_topology<>, boost::adjacency_list<boost::vecS, boost::setS, boost::undirectedS, Pancake, int, boost::no_property, boost::listS>, boost::associative_property_map<std::map<void*, boost::convex_topology<2ul>::point, std::less<void*>, std::allocator<std::pair<void* const, boost::convex_topology<2ul>::point> > > >, boost::adj_list_edge_property_map<boost::undirected_tag, int, const int&, void*, const int, boost::edge_bundle_t>, boost::detail::graph::edge_or_side<false, double>, boost::layout_tolerance<int>, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, __gnu_cxx::__normal_iterator<std::vector<int>*, std::vector<std::vector<int>, std::allocator<std::vector<int> > > >, boost::iterator_property_map<__gnu_cxx::__normal_iterator<boost::convex_topology<2ul>::point_difference*, std::vector<boost::convex_topology<2ul>::point_difference, std::allocator<boost::convex_topology<2ul>::point_difference> > >, boost::associative_property_map<std::map<void*, long unsigned int, std::less<void*>, std::allocator<std::pair<void* const, long unsigned int> > > >, boost::convex_topology<2ul>::point_difference, boost::convex_topology<2ul>::point_difference&> >::weight_type [2][2] {aka int [2][2]}’) to type ‘double (*)[2]’
 _difference_type delta = -linear_solver<Point::dimensions>::solve(dE_d_d, dE_d);

此消息太晦澀難懂，我無法理解。 它與無法將int [2][2]轉換為double (*)[2] 。 這與CostType為int的事實有關嗎？ 但是為什么不能呢？ 我非常感謝您幫助我了解自己在做錯什么。

Answer 1

確實，該錯誤表明權重必須為兩倍。

那是因為該算法調用帶有原始點的線性求解器，而失敗了，因為權重類型不是實數類型。

如果你改變

using CostType = double;

一切都編譯良好。 生活在Coliru

---

如果您堅持，則可以使用轉換：

#include <boost/property_map/transform_value_property_map.hpp>

kamada_kawai_spring_layout(g_, temp, 
            boost::make_transform_value_property_map([](int i) -> double { return i; }, get(edge_bundle, g_)),
            square_topology<>(50.0),
            side_length(50.0),
            layout_tolerance<double>(), 
            double(1), 
            propmapIndex);

如果您不想使用lambda，請使用函子：

struct to_double { double operator()(int i) const { return i; } };

kamada_kawai_spring_layout(g_, temp, 
        boost::make_transform_value_property_map(to_double(), get(edge_bundle, g_)),
        square_topology<>(50.0),
        side_length(50.0),
        layout_tolerance<double>(), 
        double(1), 
        propmapIndex);