add uses_complex class attribute and automatic save arguments

xeofs/base_model.py

@@ -33,6 +33,7 @@ class BaseModel(ABC):
     """
 
     extra_modules = []
+    uses_complex = False
 
     def __init__(self):
         # Define model parameters
@@ -142,6 +143,9 @@ def save(
         if not save_data:
             dt = insert_placeholders(dt)
 
+        if self.uses_complex and engine == "h5netcdf":
+            kwargs = {"invalid_netcdf": True} | kwargs
+
         write_model_tree(dt, path, overwrite=overwrite, engine=engine, **kwargs)
 
     @classmethod

xeofs/cross/cpcca.py

@@ -1126,6 +1126,8 @@ class ComplexCPCCA(CPCCA):
 
     """
 
+    uses_complex = True
+
     def __init__(
         self,
         n_modes: int = 2,

xeofs/single/eof.py

@@ -300,6 +300,8 @@ class ComplexEOF(EOF):
 
     """
 
+    uses_complex = True
+
     def __init__(
         self,
         n_modes: int = 2,

xeofs/single/pop.py

@@ -99,6 +99,8 @@ class POP(BaseModelSingleSet):
 
     """
 
+    uses_complex = True
+
     def __init__(
         self,
         n_modes: int = 2,