Add rhonorm1_defined_in_timerhoinput method to TimeVaryingArray.

This will replace the more complicated implementation in `torax/interpolated_params.py` in a future CL.

PiperOrigin-RevId: 725346293

torax/torax_pydantic/interpolated_param_2d.py

@@ -50,6 +50,15 @@ class TimeVaryingArray(interpolated_param_common.TimeVaryingBase):
   )
   rho_norm_grid: model_base.NumpyArray | None = None
 
+  @functools.cached_property
+  def right_boundary_conditions_defined(self) -> bool:
+    """Checks if the boundary condition at rho=1.0 is always defined."""
+
+    for rho_norm, _ in self.value.values():
+      if 1.0 not in rho_norm:
+        return False
+    return True
+
   @pydantic.model_validator(mode='before')
   @classmethod
   def _conform_data(

torax/torax_pydantic/tests/interpolated_param_2d_test.py

@@ -237,6 +237,28 @@ def test_mutation_behavior(self):
     out2 = interpolated.get_value(x=0.0)
     self.assertEqual(out2.tolist(), [v2, v2, v2])
 
+  def test_right_boundary_conditions_defined(self):
+    """Tests that right_boundary_conditions_defined works correctly."""
+
+    with self.subTest('float_input'):
+      # A single float is interpreted as defined at rho=0.
+      self.assertFalse(
+          interpolated_param_2d.TimeVaryingArray.model_validate(
+              1.0
+          ).right_boundary_conditions_defined
+      )
+
+    with self.subTest('xarray'):
+      value = xr.DataArray(
+          data=np.array([[1.0, 2.0, 3.0], [4.0, 5.0, 6.0]]),
+          coords={'time': [0.0, 1.0], 'rho_norm': [0.25, 0.5, 1.0]},
+      )
+      self.assertTrue(
+          interpolated_param_2d.TimeVaryingArray.model_validate(
+              value
+          ).right_boundary_conditions_defined
+      )
+
 
 if __name__ == '__main__':
   absltest.main()