bode function plot Help

I am trying to use the bode function on Matlab. The function i am trying to type in Matlab is H(s) = 10s/ (s+2).

This is my code

close all
clear all
s = tf('s')
H= 10*(s) /(s+2) ;
bode(H)
grid 
x=1 

The bottom is the error I keep getting.

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

Error in Untitled (line 4)

s = tf('s')

How would i fix this?

[Ameer Hamza]

The line

s = tf('s')

is correct in MATLAB's syntax. Which version of MATLAB are you using?

[Jackson]

I am using MATLAB2019b

Answer 1

[Fangjun Jiang]

You may not have the Control System Toolbox, which is required for having tf().

Run "ver control" to find out

>> H=tf([10,0],[1,2])

H =
 
  10 s
  -----
  s + 2
 
Continuous-time transfer function.

[Jackson]

This is what happened when I ran ver control.

MATLAB Version: 9.7.0.1296695 (R2019b) Update 4

Operating System: Microsoft Windows 10 Home Version 10.0 (Build 17763)

Java Version: Java 1.8.0_202-b08 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode

Warning: No properly formatted Contents.m file was found for 'control'.

[Ameer Hamza]

Jack, this shows that you don't have Control System Toolbox installed. You need that to use tf().

[Jackson]

How do I install the Control System Toolboxs to MAtlab?

[Fangjun Jiang]

Well, you need purchase, download and then install from the Mathworks website.