[SciPy-Dev] Discrete-time additions to scipy.signal

[Jeffrey Armstrong]

On Mon, 2 May 2011, Ralf Gommers wrote:
>>
>> I'll pull from here for any future work.  The cont2discrete function needs
>> some updates.  I have to admit I don't remember why I chose to use *args
>> on this function, but, for consistency with other LTI functions, it should
>> probably be combined into a single function again, but accept a tuple as
>> the system.  The tuple's length would then be checked to see if it's a
>> state-space model or a transfer function.
>
> Not sure I understand that reasoning - changing a transfer function or
> a state space model look like separate operations to me.

While the two operations are mildly different, most of the LTI functions 
in scipy.signal accept a tuple and determine whether they are dealing with 
a transfer function or a state-space model internally.  If you look at 
scipy.signal.lsim, for example, you'll see the first input is the 
"system," which can be one of three types.  For consistency, I would say 
that the cont2discrete function should behave similarly.  I'm not implying 
its the correct route to take, only that it seems that it was handled this 
way in the past.

-Jeff

Jeff Armstrong - jba at sdf.lonestar.org
SDF Public Access UNIX System - http://sdf.lonestar.org