Finding the Jacobian matrix and Ybus

[Kaled Zareer]

Hi all, 
I am a beginner at Matpower. I read the manual but I am confused about how we 
can obtain the jacobian matrix and Ybus. I see that there are Power Flow 
Derivative Functions, but I don't know how I can use them. I appreciate if 
someone provides a simple example. 
Thanks in advance
Khaled