inference: speedup addition of new groups

src/graph/inference/blockmodel/graph_blockmodel.hh

@@ -1119,7 +1119,7 @@ public:
         for (auto& p : _partition_stats)
             p.add_block();
         if (!_egroups.empty())
-            _egroups.init(_b, _eweight, _g, _bg);
+            _egroups.add_block();
         if (_coupled_state != nullptr)
             _coupled_state->coupled_resize_vertex(r);
         sync_emat();

src/graph/inference/blockmodel/graph_blockmodel_elist.hh

@@ -67,6 +67,11 @@ public:
         }
     }
 
+    void add_block()
+    {
+        _egroups.emplace_back();
+    }
+
     void clear()
     {
         _egroups.clear();

src/graph/inference/overlap/graph_blockmodel_overlap.hh

@@ -1152,7 +1152,7 @@ public:
         for (auto& p : _partition_stats)
             p.add_block();
         if (!_egroups.empty())
-            _egroups.init(_b, _eweight, _g, _bg);
+            _egroups.add_block();
         if (_coupled_state != nullptr)
             _coupled_state->coupled_resize_vertex(r);
         sync_emat();