Enable set_pped_tpedratio_nped pedestal model in build_sim

PiperOrigin-RevId: 723679418

torax/config/build_sim.py

@@ -25,6 +25,7 @@
 from torax.geometry import geometry_provider
 from torax.geometry import standard_geometry
 from torax.pedestal_model import pedestal_model as pedestal_model_lib
+from torax.pedestal_model import set_pped_tpedratio_nped
 from torax.pedestal_model import set_tped_nped
 from torax.sources import register_source
 from torax.sources import runtime_params as source_runtime_params_lib
@@ -591,14 +592,24 @@ def build_pedestal_model_builder_from_config(
     pedestal_config: dict[str, Any],
 ) -> pedestal_model_lib.PedestalModelBuilder:
   """Builds a `PedestalModelBuilder` from the input config."""
-  pedestal_model = pedestal_config.pop('pedestal_model', 'set_tped_nped')
+  pedestal_model = pedestal_config.pop('pedestal_model', None)
+  if pedestal_model is None:
+    raise ValueError(
+        "The 'pedestal_model' key is required in the pedestal configuration."
+    )
   match pedestal_model:
     case 'set_tped_nped':
       return set_tped_nped.SetTemperatureDensityPedestalModelBuilder(
           runtime_params=config_args.recursive_replace(
               set_tped_nped.RuntimeParams(), **pedestal_config
           )
       )
+    case 'set_pped_tpedratio_nped':
+      return set_pped_tpedratio_nped.SetPressureTemperatureRatioAndDensityPedestalModelBuilder(
+          runtime_params=config_args.recursive_replace(
+              set_pped_tpedratio_nped.RuntimeParams(), **pedestal_config
+          )
+      )
     case _:
       raise ValueError(f'Unknown pedestal model: {pedestal_model}')