[SciPy-User] [signal] zpk -> s domain?

[Fabrice Silva]

> > El ven., 11-02-2011 a las 09:21 -0600, Warren Weckesser escribió:
> > > On Fri, Feb 11, 2011, Neal Becker <ndbecker2 at gmail.com> wrote:
> > > > If I have a transfer function in zpk, is there a way to
> transform to
> > > > poles and zeros in s domain?
> >
> > > I'm confused by the question, because if you have the transfer
> > > function "in zpk", don't you already have the zeros, poles and
> gain?
> >
> > Is variable z unambigously related to the Laplace variable s ?
> > Frequential representations of z-domain filter are computed with
> > z = exp(jw/Fs).

> In scipy.signal (and in Matlab), "zpk" means "zeros (z), poles (p) and
> gain (k)".

No problem with that, but it could be design as a z-domain (discrete
time) transfer function, and he (Neal) would need properties in the
Laplace domain...
That is the way I understand the question.

-- 
Fabrice