Use new argument function validation technique

disturbances/index.org

@@ -217,8 +217,8 @@ We initialize all the stages.
   initializeMicroHexapod();
   initializeAxisc();
   initializeMirror();
-  initializeNanoHexapod(struct('actuator', 'piezo'));
-  initializeSample(struct('mass', 50));
+  initializeNanoHexapod('actuator', 'piezo');
+  initializeSample('mass', 50);
 #+end_src
 
 * Identification