Why does SISOTOOL not work when a function named arrow.m is in my MATLAB path in the Control System Toolbox 5.1 (R12.1)?

Why does SISOTOOL not work when a function named arrow.m is in my MATLAB path in the Control System Toolbox 5.1 (R12.1)?

Reproduction Steps:

1. Create a function called arrow.

2. Save the function in your MATLAB path

3. Type 'sisotool' in the MATLAB command window

The following error results:

 ??? Error using ==> arrow

 Too many output arguments.

 Error in ==> C:\MATLAB6p1\toolbox\control\control\sisotool.m

 On line 215  ==> sisodb.addcontrols;

Answer 1

[MathWorks Support Team]

This bug has been in MATLAB R13, Control Systems Toolbox version 5.2.

If you are using MATLAB R12.1, there are currently no known workarounds.