diff --git a/rogueviz/dhrg/embedder.cpp b/rogueviz/dhrg/embedder.cpp
index 81cb1fa5..24b180a5 100644
--- a/rogueviz/dhrg/embedder.cpp
+++ b/rogueviz/dhrg/embedder.cpp
@@ -233,6 +233,8 @@ struct dhrg_embedding : public rogueviz::embeddings::tiled_embedding {
       println(f, rogueviz::vdata[i].name.c_str(), " ", p.c_str());
       }
     }
+
+  virtual string name() { return "DHRG"; }
   };
 
 void graph_from_rv() {
diff --git a/rogueviz/embeddings/embeddings.cpp b/rogueviz/embeddings/embeddings.cpp
index b7bda551..cf558021 100644
--- a/rogueviz/embeddings/embeddings.cpp
+++ b/rogueviz/embeddings/embeddings.cpp
@@ -12,6 +12,7 @@ vector<vector<int> > directed_edges;
 rogueviz::edgetype *any;
 
 struct rv_embedding : public tiled_embedding {
+  virtual string name() { return "RogueViz internal representation"; }
   pair<cell*, hyperpoint> as_location(int id) override {
     return { vdata[id].m->base, vdata[id].m->at * C0 };
     }
@@ -92,6 +93,13 @@ void esave(string fname) {
 
 void store_gamedata(struct hr::gamedata* gd) { gd->store(current); }
 
+string embedding::get_space() {
+  shstream ss;
+  ss.write(ss.get_vernum());
+  mapstream::save_geometry(ss);
+  return ss.s;
+  }
+
 int a = arg::add3("-edgelist", [] { arg::shift(); read_edgelist(arg::args()); })
   + addHook(hooks_gamedata, 230, store_gamedata)
   + arg::add3("-write-edges", [] { arg::shift(); write_edgelist(arg::args()); })
diff --git a/rogueviz/embeddings/polar.cpp b/rogueviz/embeddings/polar.cpp
index b04e7452..65eb6e37 100644
--- a/rogueviz/embeddings/polar.cpp
+++ b/rogueviz/embeddings/polar.cpp
@@ -12,6 +12,10 @@ namespace embeddings {
   struct polar_embedding : public untiled_embedding {
     vector<polar_point> coords;
 
+    virtual string name() override { return "polar in BFKL format"; }
+
+    virtual int get_dimension() override { return 2; }
+
     hyperpoint as_hyperpoint(int id) override {
       return spin(coords[id].theta) * xpush0(coords[id].r);
       }
diff --git a/rogueviz/sag/data.cpp b/rogueviz/sag/data.cpp
index c731d4f5..f3ab4cb8 100644
--- a/rogueviz/sag/data.cpp
+++ b/rogueviz/sag/data.cpp
@@ -53,6 +53,8 @@ void save_sag_solution(const fhstream& f);
 
 struct sag_embedding : public rogueviz::embeddings::tiled_embedding {
 
+  virtual string name() { return "SAG"; }
+
   pair<cell*, hyperpoint> as_location(int id) override {
 
     ld rad = .25 * cgi.scalefactor;
@@ -78,7 +80,7 @@ struct sag_embedding : public rogueviz::embeddings::tiled_embedding {
     return sagdist[sagid[i]][0];
     }
 
-  void save(const fhstream& f) {
+  void save(fhstream& f) {
     if(!(state & SS_DATA)) throw hr_exception("save_sag_solution with no data");
     for(int i=0; i<isize(sagid); i++)
     println(f, vdata[i].name, ";", sagid[i]);