MATLAB Answers


Undefined function 'tf' for input arguments of type 'char'?

Asked by Lenin
on 1 May 2013
Latest activity Edited by Wafeeq
on 21 Mar 2016

Hey everyone,

I am running R2012b.

I type in: s = tf('s')

Undefined function 'tf' for input arguments of type 'char'.

can someone please help me?

Thanks so much!


What do you want to do with tf('s')... transfer function? What does tf represent?

on 21 Mar 2016

Do you have control Toolbox in matlab? You can write ver in matlab to check if it is available. Otherwise you can use tf if you dont have control toolbox

2 Answers

Answer by Arkadiy Turevskiy
on 1 May 2013

tf is part of Control System Toolbox. The error message you are seeing means you do not have this product on your license. You can see which toolboxes you have by typing


at the command line.

  1 Comment

The Control Systems Toolbox is included with the Student Version license, but is not installed by default.

Answer by Jan Simon
on 1 May 2013

Asking Google or searching in the forum is a good strategy to get fast answers. See


Join the 15-year community celebration.

Play games and win prizes!

Learn more
Discover MakerZone

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

Learn more

Discover what MATLAB® can do for your career.

Opportunities for recent engineering grads.

Apply Today

MATLAB Academy

New to MATLAB?

Learn MATLAB today!