Should fix #1681

gdsfactory/simulation/gtidy3d/write_sparameters.py

@@ -178,7 +178,7 @@ def write_sparameters(
     port_source_names = port_source_names or port_names
 
     for port_name in port_source_names:
-        if port_name not in port_symmetries:
+        if port_name in port_symmetries or not port_symmetries:
             sim = get_simulation(component, port_source_name=port_name, **kwargs)
             sims.append(sim)
 
@@ -217,18 +217,26 @@ def get_sparameter(
             sp[key] = sij
             sp["wavelengths"] = get_wavelengths(port_name=port_name, sim_data=sim_data)
 
+        def convert_old_fmt(s_name):
+            if len(s_name) == 3 and s_name[0]=="s":
+                s_name = f"{port_names[int(s_name[1])-1]}@0,{port_names[int(s_name[2])-1]}@0"
+            return s_name
+
         if bool(port_symmetries):
             for key, symmetries in port_symmetries.items():
                 for sym in symmetries:
-                    if key in sp:
-                        sp[sym] = sp[key]
+                    n_key = convert_old_fmt(key) # TODO contribute back
+                    n_sym = convert_old_fmt(sym)
+                    if n_key in sp:
+                        sp[n_sym] = sp[n_key]
 
         return sp
 
     for port_source_name, (_sim_name, sim_data) in zip(
         port_source_names, batch_data.items()
     ):
-        sp.update(get_sparameter(port_source_name, sim_data))
+        sp.update(get_sparameter(port_source_name, sim_data, 
+                                 port_symmetries=port_symmetries.get(port_source_name, {})))
 
     end = time.time()
     np.savez_compressed(filepath, **sp)