From: Pete Fraser on
"Fred Marshall" <fmarshallx(a)remove_the_xacm.org> wrote in message
news:BIednY5EMdtRg7HRnZ2dnUVZ_qmdnZ2d(a)centurytel.net...

> Hi Pete! How have you been?

I'm doing well thanks.
Working on a couple of interesting projects.

>
> Well, I looked into it a bit and found that I'm pretty far removed from
> the filter design toolbox / notation, etc.
>
> What have you done so far? any code samples?
> What were the results?
> Maybe that will get me going further.

I think I'll just do it the brute force way (using Matlab),
then post the code I used.

Hopefully then folks can tell me how I _should_ have done it.

Pete


From: Pete Fraser on
"Vladimir Vassilevsky" <nospam(a)nowhere.com> wrote in message
news:OP-dnf44bO7hJ7HRnZ2dnUVZ_t-dnZ2d(a)giganews.com...

> Check the FDLS method of Greg Berchin. That is one of the most elegant
> methods of designing to a prototype.

Thanks.
That looks like a very useful tool.
I'll play with the code this morning.

I'm still curious about freqsamp though.
WhereGreg talks about the pseudoinverse, I had intended
to give Matlab the exact number of points to correctly
determine the inverse. Obviously I can do this with an explicit
matrix inversion, but had assumed that freqsamp was intended
to do that. Did I just assume wrong, or am I using it incorrectly?

Thanks

Pete


From: Steve Pope on
Pete Fraser <pfraser(a)covad.net> wrote:

>I'm still curious about freqsamp though.

Near as I can tell there is not sufficient information in the
matlab documentation to state exactly (or perhaps, even generally)
what they are doing here.

If you're lucky someone from Mathworks will see your question
and answer it for you. I believe you can also ask this on the Mathworks
site, after registering.


Steve
From: Pete Fraser on
"Steve Pope" <spope33(a)speedymail.org> wrote in message
news:i0ik2r$85g$2(a)blue.rahul.net...
> Near as I can tell there is not sufficient information in the
> matlab documentation to state exactly (or perhaps, even generally)
> what they are doing here.

I thought perhaps I was looking in the wrong area.
The Mathworks help is a model of clarity, with lots of
well-thought-out examples, but when I try to dig a
little deeper I come up short.

>
> If you're lucky someone from Mathworks will see your question
> and answer it for you. I believe you can also ask this on the Mathworks
> site, after registering.

I'll try that. Thanks.


From: robert bristow-johnson on
On Jul 1, 10:59 am, Fred Marshall <fmarshallx(a)remove_the_xacm.org>
wrote:
>
> r b-j,
>
> Well, maybe I've had it wrong all these years but I'd say that the
> windowing method starts with N frequency samples where N is the length
> of the filter you want.

so then, since the DFT and iDFT are bijective (i love using fancy-
pants words), why window? if h[n] has N samples and N degrees of
freedom, so does H[k]. you specify your N frequency samples and you
can hit it perfectly with no windowing.

so, that seems curious to me.

r b-j