strange result for filter design

Started by January 6, 2003
 Hello, The following code fails completely. Instead of producing the requested filter it returns the filter coefficients as all zeros. Here's the code: % design narrowband filter f = [0.444 0.49 0.51 0.556 ]; a = [0 1 0]; dev = [0.0316 0.05 0.0316]; % estimate order using remezord [n,fo,ao,w] = remezord(f,a,dev) % get filter coefficients b = remez(n,fo,ao,w); % ERROR: the b vector is all zeros. % How is this possible? thanks
 Moshe Malkin- What is the order of the filter returned by remezord? Jeff Brower Signalogic > The following code fails completely. > Instead of producing the requested filter > it returns the filter coefficients as all zeros. > > Here's the code: > > % design narrowband filter > f = [0.444 0.49 0.51 0.556 ]; > a = [0 1 0]; > dev = [0.0316 0.05 0.0316]; > % estimate order using remezord > [n,fo,ao,w] = remezord(f,a,dev) > % get filter coefficients > b = remez(n,fo,ao,w); > > % ERROR: the b vector is all zeros. > % How is this possible? > thanks
 Hi, That appears to be a bug in remez. See http://www.mathworks.com/support/solutions/data/31015.shtml Navan --- Moshe Malkin <> wrote:> Hello, > The following code fails completely. > Instead of producing the requested filter > it returns the filter coefficients as all zeros. > > Here's the code: > > % design narrowband filter > f = [0.444 0.49 0.51 0.556 ]; > a = [0 1 0]; > dev = [0.0316 0.05 0.0316]; > % estimate order using remezord > [n,fo,ao,w] = remezord(f,a,dev) > % get filter coefficients > b = remez(n,fo,ao,w); > > % ERROR: the b vector is all zeros. > % How is this possible? > thanks __________________________________________________
thats right. I'm using Matlab version 5.2 and the code runs absolutely fine.
the output of the code is attached.
-priyank

--- navaneetha krishnan <> wrote:
> Hi,
>
> That appears to be a bug in remez.
>
> See
> http://www.mathworks.com/support/solutions/data/31015.shtml
>
> Navan
>
> --- Moshe Malkin <> wrote:
> > Hello,
> >
> >
> > The following code fails completely.
> > Instead of producing the requested filter
> > it returns the filter coefficients as all zeros.
> >
> > Here's the code:
> >
> > % design narrowband filter
> > f = [0.444 0.49 0.51 0.556 ];
> > a = [0 1 0];
> > dev = [0.0316 0.05 0.0316];
> > % estimate order using remezord
> > [n,fo,ao,w] = remezord(f,a,dev)
> > % get filter coefficients
> > b = remez(n,fo,ao,w);
> >
> > % ERROR: the b vector is all zeros.
> > % How is this possible?
> >
> >
> > thanks > __________________________________________________

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