Do you have any MATLAB workspace variables pre-defined and the name is such as,'tf' ,'sterpplot', or ' DynamicSystem'?
Needless to say, double defined same name of pre-defined functions and workspace variable is prohibited.
The reason is priority of workscape name and functionname depends on the prioirty of MATLAB path.
If you have 'tf' where is in MATLAB workspace variable , this is the highest priority.
Second, if you have 'tf' function or other famous name's function you personally programed in current directory which name is same as functions as provided by toolboxes , the function located in current directory has higher priority than Toolboxes.
Please check above.
In my environment , your scriput runs normally.