Minimal Working - seems too good?!

Classes/Filter.m

@@ -40,7 +40,21 @@ classdef Filter
 
         end
 
-        function yout = process(obj,xin)
+         function signalclass_out = process(obj,signalclass_in)
+
+             % actual processing of the signal 
+            signalclass_in.signal = obj.process_(signalclass_in.signal); 
+
+             % append to logbook
+            filterdesc = [num2str(obj.filtdegree),'. order ',char(obj.filterType),' filter with f_cutoff at ', num2str(obj.f_cutoff*1e-9), ' GHz.'];
+            signalclass_in  = signalclass_in.logbookentry(filterdesc);
+
+             % write to output
+            signalclass_out = signalclass_in;
+
+        end
+
+        function yout = process_(obj,xin)
 
             obj.signal_length = length(xin);