Graph: fix vorder parameter when not contiguous

src/graph/graph_copy.cc

@@ -189,12 +189,24 @@ struct do_graph_copy
                     vector<pair<std::reference_wrapper<boost::any>,std::reference_wrapper<boost::any>>>& vprops,
                     vector<pair<std::reference_wrapper<boost::any>,std::reference_wrapper<boost::any>>>& eprops) const
     {
+        vector<size_t> vs;
+        for (auto v : vertices_range(src))
+            vs.push_back(v);
+        std::sort(vs.begin(), vs.end(),
+                  [&](auto u, auto v)
+                  {
+                      return get(vertex_order, u) < get(vertex_order, v);
+                  });
+        vector<size_t> pos(num_vertices(src));
+        for (size_t i = 0; i < vs.size(); ++i)
+            pos[vs[i]] = i;
+
         vector<size_t> index_map(num_vertices(src));
         for (auto v : vertices_range(src))
         {
             if (src_vertex_index[v] >= index_map.size())
                 index_map.resize(src_vertex_index[v] + 1);
-            auto new_v = get(vertex_order, v);
+            auto new_v = pos[v];
             while (size_t(new_v) >= num_vertices(tgt))
                 add_vertex(tgt);
             index_map[src_vertex_index[v]] = tgt_vertex_index[new_v];

src/graph_tool/__init__.py

@@ -1662,8 +1662,10 @@ class Graph(object):
 
                 # The vertex ordering
                 if vorder is None:
-                    vorder = gv.new_vertex_property("int")
-                    vorder.fa = numpy.arange(gv.num_vertices())
+                    vorder = gv.new_vertex_property("int",
+                                                    vals=numpy.arange(gv.num_vertices()))
+                else:
+                    vorder = vorder.copy("int")
 
                 # The actual copying of the graph and property maps
                 self.__graph = libcore.GraphInterface(gv.__graph, False,

src/graph_tool/inference/blockmodel.py

@@ -97,8 +97,12 @@ def get_block_graph(g, B, b, vcount=None, ecount=None, rec=None, drec=None):
             cg.ep["drec%d" % i] = ae[0]
             del ae[0]
 
+    rs = numpy.setdiff1d(numpy.arange(B, dtype="int"), br.fa,
+                         assume_unique=True)
+    if len(rs) > 0:
+        cg.add_vertex(len(rs))
+        br.fa[-len(rs):] = rs
     cg = Graph(cg, vorder=br)
-    cg.add_vertex(B - cg.num_vertices())
 
     cg.gp.rec = cg.new_gp("object", [])
     if rec is not None: