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

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!

[Kye Taylor]

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

[Wafeeq]

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

Answer 1

[Arkadiy Turevskiy]

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

 ver

at the command line.

[Walter Roberson]

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

Answer 2

[Jan]

Asking Google or searching in the forum is a good strategy to get fast answers. See http://www.mathworks.com/matlabcentral/answers/65972.