Commit dc067716 authored by Tiago Peixoto's avatar Tiago Peixoto
Browse files

all_shortest_paths(): Fix bug with weighted graphs

parent e64b612d

src/graph/topology/graph_distance.cc

+16 −8
Original line number Diff line number Diff line
@@ -448,8 +448,8 @@ void get_dists(GraphInterface& gi, size_t source, boost::python::object tgt, 
    }

}



template <class Graph, class Dist, class Pred, class Preds>

void get_all_preds(Graph g, Dist dist, Pred pred, Preds preds)

template <class Graph, class Dist, class Pred, class Weight, class Preds>

void get_all_preds(Graph g, Dist dist, Pred pred, Weight weight, Preds preds)

{

    parallel_vertex_loop

        (g,
@@ -457,18 +457,19 @@ void get_all_preds(Graph g, Dist dist, Pred pred, Preds preds) 
         {

            if (size_t(pred[v]) == v)

                return;

            auto d = dist[pred[v]];

            auto d = dist[v];

            typedef decltype(d) dist_t;

            for (auto e : in_or_out_edges_range(v, g))

            {

                auto u = boost::is_directed(g) ? source(e, g) : target(e, g);

                if (dist[u] == d)

                if (dist_t(dist[u] + get(weight, e)) == d)

                    preds[v].push_back(u);

            }

         });

};



void do_get_all_preds(GraphInterface& gi, boost::any adist,

                      boost::any apred, boost::any apreds)

                      boost::any apred, boost::any aweight, boost::any apreds)

{

    typedef property_map_type

        ::apply<int64_t, GraphInterface::vertex_index_map_t>::type pred_map_t;
@@ -478,11 +479,18 @@ void do_get_all_preds(GraphInterface& gi, boost::any adist, 
    pred_map_t pred = any_cast<pred_map_t>(apred);

    preds_map_t preds = any_cast<preds_map_t>(apreds);



    typedef UnityPropertyMap<int,GraphInterface::edge_t> weight_map_t;

    typedef boost::mpl::push_back<edge_scalar_properties, weight_map_t>::type

        weight_props_t;



    if (aweight.empty())

        aweight = weight_map_t();



    run_action<>()

        (gi, [&](auto& g, auto dist)

        (gi, [&](auto& g, auto dist, auto weight)

             {get_all_preds(g, dist, pred.get_unchecked(num_vertices(g)),

                            preds.get_unchecked(num_vertices(g)));},

         vertex_scalar_properties())(adist);

                            weight, preds.get_unchecked(num_vertices(g)));},

         vertex_scalar_properties(), weight_props_t())(adist, aweight);

}

src/graph_tool/topology/__init__.py

+5 −2
Original line number Diff line number Diff line
@@ -1849,7 +1849,7 @@ def shortest_path(g, source, target, weights=None, negative_weights=False, 
        v = p

    return vlist, elist



def all_predecessors(g, dist_map, pred_map):

def all_predecessors(g, dist_map, pred_map, weights=None):

    """Return a property map with all possible predecessors in the search tree

        determined by ``dist_map`` and ``pred_map``.
@@ -1862,6 +1862,8 @@ def all_predecessors(g, dist_map, pred_map): 
        vertices.

    pred_map : :class:`~graph_tool.PropertyMap` (optional, default: None)

        Vertex property map with the predecessors in the search tree.

    weights : :class:`~graph_tool.PropertyMap` (optional, default: None)

        The edge weights.



    Returns

    -------
@@ -1875,6 +1877,7 @@ def all_predecessors(g, dist_map, pred_map): 
    libgraph_tool_topology.get_all_preds(g._Graph__graph,

                                         _prop("v", g, dist_map),

                                         _prop("v", g, pred_map),

                                         _prop("e", g, weights),

                                         _prop("v", g, preds))

    return preds
@@ -1952,7 +1955,7 @@ def all_shortest_paths(g, source, target, weights=None, negative_weights=False, 
                                               negative_weights=negative_weights,

                                               pred_map=True)

    if all_preds_map is None:

        all_preds_map = all_predecessors(g, dist_map, pred_map)

        all_preds_map = all_predecessors(g, dist_map, pred_map, weights)



    path_iterator = \

        libgraph_tool_topology.get_all_shortest_paths(g._Graph__graph,