lemon/fractional_matching.h
changeset 874 d8ea85825e02
parent 871 86613aa28a0c
child 876 7f6e2bd76654
equal deleted inserted replaced
1:a3f5c5ba7a87 2:157933a5075a
   656   ///
   656   ///
   657   /// The algorithm can be executed with the run() function.
   657   /// The algorithm can be executed with the run() function.
   658   /// After it the matching (the primal solution) and the dual solution
   658   /// After it the matching (the primal solution) and the dual solution
   659   /// can be obtained using the query functions.
   659   /// can be obtained using the query functions.
   660   ///
   660   ///
   661   /// If the value type is integer, then the primal and the dual
   661   /// The primal solution is multiplied by
   662   /// solutions are multiplied by
   662   /// \ref MaxWeightedFractionalMatching::primalScale "2".
   663   /// \ref MaxWeightedFractionalMatching::primalScale "2" and
   663   /// If the value type is integer, then the dual
   664   /// \ref MaxWeightedFractionalMatching::dualScale "4" respectively.
   664   /// solution is scaled by
       
   665   /// \ref MaxWeightedFractionalMatching::dualScale "4".
   665   ///
   666   ///
   666   /// \tparam GR The undirected graph type the algorithm runs on.
   667   /// \tparam GR The undirected graph type the algorithm runs on.
   667   /// \tparam WM The type edge weight map. The default type is
   668   /// \tparam WM The type edge weight map. The default type is
   668   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<int>".
   669   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<int>".
   669 #ifdef DOXYGEN
   670 #ifdef DOXYGEN
   686     typedef typename Graph::template NodeMap<typename Graph::Arc>
   687     typedef typename Graph::template NodeMap<typename Graph::Arc>
   687     MatchingMap;
   688     MatchingMap;
   688 
   689 
   689     /// \brief Scaling factor for primal solution
   690     /// \brief Scaling factor for primal solution
   690     ///
   691     ///
   691     /// Scaling factor for primal solution. It is equal to 2 or 1
   692     /// Scaling factor for primal solution.
   692     /// according to the value type.
   693     static const int primalScale = 2;
   693     static const int primalScale =
       
   694       std::numeric_limits<Value>::is_integer ? 2 : 1;
       
   695 
   694 
   696     /// \brief Scaling factor for dual solution
   695     /// \brief Scaling factor for dual solution
   697     ///
   696     ///
   698     /// Scaling factor for dual solution. It is equal to 4 or 1
   697     /// Scaling factor for dual solution. It is equal to 4 or 1
   699     /// according to the value type.
   698     /// according to the value type.
  1327     /// This function returns \c true if the given edge is in the
  1326     /// This function returns \c true if the given edge is in the
  1328     /// found matching. The result is scaled by \ref primalScale
  1327     /// found matching. The result is scaled by \ref primalScale
  1329     /// "primal scale".
  1328     /// "primal scale".
  1330     ///
  1329     ///
  1331     /// \pre Either run() or start() must be called before using this function.
  1330     /// \pre Either run() or start() must be called before using this function.
  1332     Value matching(const Edge& edge) const {
  1331     int matching(const Edge& edge) const {
  1333       return Value(edge == (*_matching)[_graph.u(edge)] ? 1 : 0)
  1332       return (edge == (*_matching)[_graph.u(edge)] ? 1 : 0)
  1334         * primalScale / 2 + Value(edge == (*_matching)[_graph.v(edge)] ? 1 : 0)
  1333         + (edge == (*_matching)[_graph.v(edge)] ? 1 : 0);
  1335         * primalScale / 2;
       
  1336     }
  1334     }
  1337 
  1335 
  1338     /// \brief Return the fractional matching arc (or edge) incident
  1336     /// \brief Return the fractional matching arc (or edge) incident
  1339     /// to the given node.
  1337     /// to the given node.
  1340     ///
  1338     ///
  1421   /// \f[\min \sum_{u \in V}y_u \f]
  1419   /// \f[\min \sum_{u \in V}y_u \f]
  1422   ///
  1420   ///
  1423   /// The algorithm can be executed with the run() function.
  1421   /// The algorithm can be executed with the run() function.
  1424   /// After it the matching (the primal solution) and the dual solution
  1422   /// After it the matching (the primal solution) and the dual solution
  1425   /// can be obtained using the query functions.
  1423   /// can be obtained using the query functions.
  1426 
  1424   ///
  1427   /// If the value type is integer, then the primal and the dual
  1425   /// The primal solution is multiplied by
  1428   /// solutions are multiplied by
  1426   /// \ref MaxWeightedPerfectFractionalMatching::primalScale "2".
  1429   /// \ref MaxWeightedPerfectFractionalMatching::primalScale "2" and
  1427   /// If the value type is integer, then the dual
  1430   /// \ref MaxWeightedPerfectFractionalMatching::dualScale "4" respectively.
  1428   /// solution is scaled by
       
  1429   /// \ref MaxWeightedPerfectFractionalMatching::dualScale "4".
  1431   ///
  1430   ///
  1432   /// \tparam GR The undirected graph type the algorithm runs on.
  1431   /// \tparam GR The undirected graph type the algorithm runs on.
  1433   /// \tparam WM The type edge weight map. The default type is
  1432   /// \tparam WM The type edge weight map. The default type is
  1434   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<int>".
  1433   /// \ref concepts::Graph::EdgeMap "GR::EdgeMap<int>".
  1435 #ifdef DOXYGEN
  1434 #ifdef DOXYGEN
  1452     typedef typename Graph::template NodeMap<typename Graph::Arc>
  1451     typedef typename Graph::template NodeMap<typename Graph::Arc>
  1453     MatchingMap;
  1452     MatchingMap;
  1454 
  1453 
  1455     /// \brief Scaling factor for primal solution
  1454     /// \brief Scaling factor for primal solution
  1456     ///
  1455     ///
  1457     /// Scaling factor for primal solution. It is equal to 2 or 1
  1456     /// Scaling factor for primal solution.
  1458     /// according to the value type.
  1457     static const int primalScale = 2;
  1459     static const int primalScale =
       
  1460       std::numeric_limits<Value>::is_integer ? 2 : 1;
       
  1461 
  1458 
  1462     /// \brief Scaling factor for dual solution
  1459     /// \brief Scaling factor for dual solution
  1463     ///
  1460     ///
  1464     /// Scaling factor for dual solution. It is equal to 4 or 1
  1461     /// Scaling factor for dual solution. It is equal to 4 or 1
  1465     /// according to the value type.
  1462     /// according to the value type.
  2062     /// This function returns \c true if the given edge is in the
  2059     /// This function returns \c true if the given edge is in the
  2063     /// found matching. The result is scaled by \ref primalScale
  2060     /// found matching. The result is scaled by \ref primalScale
  2064     /// "primal scale".
  2061     /// "primal scale".
  2065     ///
  2062     ///
  2066     /// \pre Either run() or start() must be called before using this function.
  2063     /// \pre Either run() or start() must be called before using this function.
  2067     Value matching(const Edge& edge) const {
  2064     int matching(const Edge& edge) const {
  2068       return Value(edge == (*_matching)[_graph.u(edge)] ? 1 : 0)
  2065       return (edge == (*_matching)[_graph.u(edge)] ? 1 : 0)
  2069         * primalScale / 2 + Value(edge == (*_matching)[_graph.v(edge)] ? 1 : 0)
  2066         + (edge == (*_matching)[_graph.v(edge)] ? 1 : 0);
  2070         * primalScale / 2;
       
  2071     }
  2067     }
  2072 
  2068 
  2073     /// \brief Return the fractional matching arc (or edge) incident
  2069     /// \brief Return the fractional matching arc (or edge) incident
  2074     /// to the given node.
  2070     /// to the given node.
  2075     ///
  2071     ///