Re: Linear time-invariant time response kernel, MATLAB vs Octave Code

[Lukas Reichlin]

On 18.09.2014, at 15:47, babelproofreader <address@hidden> wrote:

> I am trying to get some MATLAB scripts to run in Octave, but have a problem
> with the following line of code:
> 
> x = ltitr( a, b, u, x0 ) ;
> 
> which throws an error in Octave.
> 
> Online research shows that the ltitr function is an internal MATLAB function
> that returns the Linear time-invariant time response kernel for the given
> inputs. This sounds as if it should be a common DSP requirement, so I feel
> that this must be implemented directly in Octave, or in the latest Control
> package from Source Forge. However, I can't seem to find an Octave
> equivalent. I've read the documentation for the latest Octave Control
> package and maybe I should be using the functions lsim.m or ss.m or dss.m
> but I'm not really sure.
> 
> Can anyone enlighten me? If it's not implemented in Octave, maybe some
> online reference to code that I could use to write my own ltitr function?


You could start from something like this:


function x = ltitr (a, b, u, x0)

  x = lsim (ss (a, b, [], [], -1), u, [], x0);

endfunction


Hope this helps,
Lukas