How to use Lyapunov function in Julia


Please can anyone guide me how to use the Lyapunov function in julia?


Which Lyapunov function are you referring to?


Thank you so much for your quick response. The community is strong here.
The one that we use in Matlab as


where, ‘a’ variable is a matrix.


Are you talking about

help?> lyap
search: lyap polygamma displayable

  lyap(A, C)

  Computes the solution X to the continuous Lyapunov equation AX + XA' + C =
  0, where no eigenvalue of A has a zero real part and no two eigenvalues are
  negative complex conjugates of each other.



There is no single-argument version in the Matlab documentation, so it is hard to guess what you need. Also, note that Lyapunov functions and Lyapunov equations are different concepts.

The community is indeed strong here, but putting some effort into asking questions also helps.


There is a discussion here:

I found this using Google, having never heard of the Lyapunov function in this context. (There are other things called Lyapunov functions and it would have been useful for you to actually explain what you needed.) Did you actually try Google?


I have been using julia for 03 days only. I don’t understand many many things. Google was not helpful. I need to learn from experienced julia programmers like you. I also believe that, communicating with people in the community helps you learn and in the process you make good friends.


Actually I am really really new to julia. And I am new to coding as well. I am sorry brother. I will try harder next time.


Welcome to Julia! Do feel free to ask any questions you have. You will get a better response if your questions are as specific as possible.


Thank you so much. I would ask you for another help, if you don’t mind. Since, I am new to programming and julia as well can you please guide me to a group or web page where I can learn by solving some exercise and examples. Like a step by step learning group or a community? Thank you again.


I have been reading this wikibook:

Of course, the documentation is also very good:



Thank you so much. I will study these two books. Then lets see how far I can get.
Thank you again for your support and advise.


If you’re looking for utilities to analyze control systems, the package ControlSystems.jl provides Lyapunov functions for discrete and continuous control systems.
dlyap covar