uncertain_blockmodel: Fix sampling issues

src/graph/inference/uncertain/graph_blockmodel_measured.hh

@@ -93,7 +93,10 @@ struct Measured
             }
 
             size_t N = num_vertices(_g);
+            if (_self_loops)
                 _NP = graph_tool::is_directed(_g) ? N * N : (N * (N + 1)) / 2;
+            else
+                _NP = graph_tool::is_directed(_g) ? N * (N - 1) : (N * (N - 1)) / 2;
 
             _N += (_NP - gE) * _n_default;
             _X += (_NP - gE) * _x_default;

src/graph/inference/uncertain/graph_blockmodel_uncertain_mcmc.hh

@@ -77,7 +77,7 @@ struct MCMC
         {
             size_t u = _slist[ei];
             size_t v = _tlist[ei];
-            if (u > num_vertices(_state._g))
+            if (u >= num_vertices(_state._g))
                 std::tie(u, v) = _e;
             return {u, v};
         }