Use raise NotImplentedError, not NotImplemented in InputOutputSystem._rhs

roryyorke · roryyorke · commit c70a377fc82e · 2022-11-20T07:48:28.000+02:00
diff --git a/control/iosys.py b/control/iosys.py
@@ -366,8 +366,8 @@ def _rhs(self, t, x, u):
         you may want to use :meth:`dynamics`.
 
         """
-        NotImplemented("Evaluation not implemented for system of type ",
-                       type(self))
+        raise NotImplementedError("Evaluation not implemented for system of type ",
+                                  type(self))
 
     def dynamics(self, t, x, u, params=None):
         """Compute the dynamics of a differential or difference equation.
