Re: A question on Matlab compatibility

[Paul Kienzle]

On Sep 16, 2006, at 7:06 PM, Ron Crummett wrote:

> All I am really trying to do is raise the issue of compatibility.
> If Matlab has a function that performs a series cascade of two
> systems and it is called 'series', and Octave has one that does
> the same thing, also called 'series', but it is preferred that
> you use this other one called 'sysmult' instead...why not just
> call it 'series' and maintain compatibility?
>
> This is just one example that I have seen.  There are others...for
> example, there are no filter conversion functions such as 'lp2lp'
> and 'lp2bp' - instead, there is just one, 'sftrans', which I have 
> never been able to figure out and which has no Matlab counterpart.

When I wrote the IIR functions I had no use for lp2xx, and it
made more sense to me to put the conditional which converts
W and stop parameters into low pass, band pass, etc. in one
function (sftrans, or splane frequency transfrom) rather than
each of butter, cheby1, cheby2, ellip.

You are welcome to create lp2xx functions, either by calling
sftrans yourself or by pulling the code for the individual
cases out of sftrans and calling lp2xx from sftrans.  In either
case it will be a little bit of work to figure out what matlab
is doing with the gain.

- Paul