diff --git a/rogueviz/sag/annealing.cpp b/rogueviz/sag/annealing.cpp
index f9be9741..82fb8c08 100644
--- a/rogueviz/sag/annealing.cpp
+++ b/rogueviz/sag/annealing.cpp
@@ -47,6 +47,8 @@ void saiter() {
     for(int ii=0; ii<s; ii++) sid2 = hrand_elt(neighbors[sid2]);
     }
   int t2 = allow_doubles ? -1 : sagnode[sid2];
+
+  if(fixed_position[t1] || (t2 >= 0 && fixed_position[t2])) return;
   
   sagnode[sid1] = -1; sagid[t1] = -1;
   sagnode[sid2] = -1; if(t2 >= 0) sagid[t2] = -1;
diff --git a/rogueviz/sag/data.cpp b/rogueviz/sag/data.cpp
index 1ebda6b1..1631e60b 100644
--- a/rogueviz/sag/data.cpp
+++ b/rogueviz/sag/data.cpp
@@ -28,6 +28,8 @@ vector<edgeinfo> sagedges;
 vector<vector<int>> edges_yes, edges_no;
 vector<vector<pair<int, double>>> edge_weights;
 
+vector<bool> fixed_position;
+
 ld edgepower=1, edgemul=1;
 
 void init();
@@ -46,6 +48,8 @@ void prepare_graph() {
   
   edges_yes.clear(); edges_yes.resize(DN);
   edges_no.clear(); edges_no.resize(DN);
+
+  fixed_position.clear(); fixed_position.resize(DN);
   
   for(int i=0; i<DN; i++) for(int j=0; j<DN; j++) if(i != j) {
     if(alledges.count({i, j}))
@@ -386,6 +390,26 @@ int data_read_args() {
     PHASE(3); shift(); sag::save_sag_solution(args());
     }
 
+  else if(argis("-sag-fix")) {
+    shift(); int id = getid(args());
+    if(id >= isize(sagid)) throw hr_exception("bad id in -sag-fix");
+    fixed_position[id] = true;
+    }
+
+  else if(argis("-sag-move-to")) {
+    shift(); int sid1 = getid(args());
+    if(sid1 < 0 || sid1 >= isize(sagid)) throw hr_exception("bad id in -sag-move-to");
+    shift(); int t2 = argi();
+    if(t2 < 0 || t2 >= isize(sagnode)) throw hr_exception("bad id in -sag-move-to");
+    int sid2 = sagid[t2];
+    int t1 = allow_doubles ? -1 : sagnode[sid1];
+    sagnode[sid1] = t2; sagid[t2] = sid1;
+    if(sid2 >= 0) sagnode[sid2] = t1; sagid[t1] = sid2;
+    compute_cost();
+    create_viz();
+    }
+
+
   else return 1;  
 #endif
   return 0;