[sdiy] ot: help! Dolph-Tchebycheff window

[Magnus Danielson]

From: "Czech Martin" <Martin.Czech at Micronas.com>
Subject: [sdiy] ot: help! Dolph-Tchebycheff window
Date: Thu, 27 Mar 2003 13:42:56 +0100

Martin,

> Some people say that the internet is a pile of sh*t.
> I generally do not aggree, but in this case they are right!

The trouble with the Internet as that "The Good Stuff" isn't as well organized
as you would wish it where. Sometimes it is out there, but you can't figure
out how to make Google or a 16 hour websearch make sense.

>From the information theory we learn that it takes energy to filter out
information which is not meaningfull (in some context). When you have done
your filtering you really should attempt to "store the state" for you (and
possibly others) to be able to more quickly get to it the next time. This
means you will not have to wast that energy again.

Thus: Link it in on a webpage! Store the articles on disk!

> I'm looking for a correct procedure to compute the so called
> Dolph-Tchebycheff Window.
> So far, all the programs , algorithms and graphs proved to
> be wrong, since the spectrum of the computed window
> did not have any equi ripple properties. Sometimes
> this was very evident from the pictures in the particular
> paper. People seem not to notice!
> Very often the initial window spectrum is derived in the right
> way. But all of the back transforms into time domain are faulty.
> 
> So , please, could anyone of you good people point
> me to a correct derivation/program code?

Which references have you tried?
I have some stuff on windowing at home, I could dig into them if you haven't
tried them. I could also go for a library expedition tomorrow (I plan to do
that anyway) so if you toss me the some bones I could have a lookout after it.

Cheers,
Magnus