Re: Not able to add delay to transfer function

[Torsten Lilge]

On Wed, 2020-07-29 at 13:52 -0500, shall689 wrote:
> Hello,
> 
> octave returns "exp: not defined for class" when I multiply a transfer
> function by exp(-s*tau).  
> 
> Is there any other way to add a delay?
> 
> Stephen
> 

AFAIK, this is not (yet) possible. You can try padecoef () [1] for
approximating the delay by poles/zeros. Example: PT1 (T1=0.5, K=1) with
0.3s delay:

>> [num,den] = padecoef (0.3,8)
>> step (tf (1,[0.5 1])*tf (num,den))


Torsten


[1]   https://octave.sourceforge.io/octave/function/padecoef.html