RE: Dumb question about step

[Giuseppe Marullo]

Thank you for your explanation, it does make sense. I wonder if there a list
of these "differences" between matlab and octave, before I start using
octave instead *fiddling* with matlab.

Giuseppe

-----Original Message-----
From: A. Scottedward Hodel [mailto:address@hidden
Sent: Saturday, February 02, 2008 9:07 PM
To: address@hidden
Cc: Octave_post
Subject: Re: Dumb question about step


The current step function is the second iteration in the Octave
Control Systems Toolbox (OCST).  In our first iteration, we followed
the syntax you suggest, e.g.,

step (num,den)
step(num,den,T)
step(zer,pol,k)
step(zer,pol,k,T)
step(A,B,C)
step(A,B,C,D)
step(A,B,C,D,T)

etc.

Because of the ambiguity in arguments (3 arguments: is it a tf , zp,
or ss?) etc., the interpretation of input arguments was a problem and
took up the bulk of each m-file.  In our second iteration, we went to
a more object oriented approach,

step(tf(num,den))

so that there was no question what the input data format was.
Shortly thereafter, MATLAB also released object oriented toolboxes.
(I am sure we were both working on our approaches in parallel).

It is possible to rewrite the routines to accept both the new syntax
and the old syntax, but it would require some  care and testing, and
that would not be a trivial effort.  (That is to say, I probably
won't be the one to do it.)

Yours,

A S Hodel  http://www.eng.auburn.edu/~hodelas

On Feb 2, 2008, at 5:40 AM, Giuseppe Marullo wrote:

> Javier,
> many thanks about your answer. This will solve my problem (it works
> now) but
> I am wondering if there is a way to use directly matlab sentences.
> I know it is my fault not knowing much and not wanting to dig
> deeper than
> the minimum but
>  it could be great to be able to handle at least the basic stuff
> without
> having to change it.
> Is there any compatibility switch that will turn octave into a
> "strict"
> matlab clone?
>
> Thanks again,
>
> Giuseppe
>
> -----Original Message-----
> From: Javier Arantegui [mailto:address@hidden
> Sent: Saturday, February 02, 2008 12:22 PM
> To: address@hidden
> Cc: address@hidden
> Subject: Re: Dumb question about step
>
>
> Hi!
>
> On Feb 2, 2008 10:18 AM, Giuseppe Marullo <address@hidden> wrote:
>> step(num,den)
>
> That's easy. You should user the function tf() to define your transfer
> function. Type this instead:
>
> step(tf(num,den))
>
> Or define it like this:
>
> G=tf(num, den)
>
> and then:
>
> step(G)
>
> To view your function transfer, use sysout():
>
> sysout(G)
>
>
> Javier
>
>
> --
> Lee mi blog: "Un pequeño paso para Neil" http://up3n.wordpress.com/
>
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