On Wed, 11 Jan 2006 16:44:48 -0500, Stan Pawlukiewicz
<s...@spam.mitre.org> wrote:

>robert bristow-johnson wrote:
>
>(big snip)
>
>s" that the data
>> passed to it is one period of a discrete, infinite, and periodic
>> sequence of numbers that has period length of N.
>> 
>> i fail to see this as a misuse of the language to make a point and to
>> say "The DFT is not a living creature so it cannot make assumptions..."
>> fails to refute the point i make about the inherent periodic extension
>> of data made by the DFT.
>>  
>You really don't make the point either.  I've read the periodic 
>extension perspective in Brigham's FFT book, but I have never seen it in 
>in any book that talks about Sturm Louville boundary value problems. 
>There is nothing that makes the periodic extension principle more 
>fundamental than the filter bank perspective,the orthogonal 
>decomposition perspective, or the sampling of the Z transform on the 
>unit circle perspective. It might make circular convolution a bit more 
>intuitive but it really just confuses the hell of people when you 
>present the overlap add method of filtering, and is kind of tangential 
>when you start talking about statistical spectral estimation.

I'm late coming into this one because I just haven't had time to keep
up with all the posts flying by.

Has anybody argued the windowing perspective yet?  i.e., the
"periodicity" is only a consequence of the rectangular window inherent
with the DFT?

This is how we heated the discussion up years ago...   ;)

One of these days we can do a DFT on the last twenty years of comp.dsp
posts to see the average period of how often this topic comes up.  ;)
It seems to be pretty regular...



Eric Jacobsen
Minister of Algorithms, Intel Corp.
My opinions may not be Intel's opinions.
http://www.ericjacobsen.org

in article t...@4ax.com, Eric Jacobsen at
e...@ieee.org wrote on 01/11/2006 19:17:

> Has anybody argued the windowing perspective yet?  i.e., the
> "periodicity" is only a consequence of the rectangular window inherent
> with the DFT?

ooooo!  (aim taken...) Blam! Blam! Blam! Blam!

:-)

-- 

r b-j                  r...@audioimagination.com

"Imagination is more important than knowledge."