rv:: sag:: initialize sag on sag_bridging

rogueviz/sag/experiments.cpp

@@ -240,6 +240,7 @@ void output_stats() {
   }
 
 void sag_bridging(bool tw, int iters) {
+  init();
   init_cells();
   after_data();
   println(hlog, "SAG for bridging started");

rogueviz/sag/sag.cpp

@@ -345,7 +345,7 @@ void init() {
 
   weight_label = "min weight";
   temperature = 0; sagmode = sagOff;
-  sag_edge = add_edgetype("SAG edge");
+  ensure_sag_edge();
   }
 
 void clear() {