Beginner in trouble (re: transfer functions and bodes)

[Douglasjam]

I'm trying to do a bode plot of a transfer function without using the "bode()" command. I need to use the subplot function to put two plots on one figure as well as plot the gain (dB) and phase (degree) using a semilog axis.

Any help would be truely apreciated!

The transfer function is:

G(s) =

70(s + 20)
---------------------------
(s+7) (s+70) (s^2 + 2s + 25)

 

[GregLocock]

And why would a professional engineer be forbidden from using the bode command?

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.