Re: trivial digital filter

[A S Hodel]

Sorry for the delay in response; I've been updating my octave 
installation on both of my machines.

Try either

sys = tf([1 1][1,0],1e-3);
        or, equivalently,
sys = fir2sys([1, 1],1e-3);

The octave control systems toolbox requires "proper" transfer 
functions, i.e., at least as many poles
as zeros.  A causal FIR system with N zeros has at least N poles, all 
of them at z = 0.


On Wednesday, March 3, 2004, at 09:21 AM, Hugo Coolens wrote:

> I'm trying to simulate the following digital filter in octave:
> sys=tf([1 1],[1],1e-3)
> However this gives an error message:
> # of poles (0) < # of zeros (1)
> Which is of course clear enough but I wonder whether there is a way to 
> use
> a "similar method" as the one above in octave for this kind of filter?
>
> regards,
> Hugo
>
>
> To demonstrate the filter I already simulated its behaviour in the time
> domain as follows:
> a=[1];
> b=[1 1];
> fs=1000;
> time=0:1/fs:40e-3;
> x=sin(2*pi*200*time);
> y=filter(b,a,x);
> stem(time,y)
>
>
>
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A. S. Hodel Dept. ECE, 200 Broun Hall, Auburn University AL 36849-5201
(334) 844-1854/fax(334) 844-1809, 
http://www.eng.auburn.edu/users/hodelas , address@hidden



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