Talk:Window function
From Wikipedia, the free encyclopedia
Contents |
[edit] Scalloping loss
The paragraph about scalloping loss seems to refer to a figure that isn't there. Sdrpyh 06:23, 14 February 2007 (UTC)
- It's just as Bob K wrote it on 18 December 2005, this diff. The figure above is still the same "zoom view" figure in the previous subsection. I find it a bit confusing, too. Dicklyon 06:30, 14 February 2007 (UTC)
[edit] All about frequency analysis?
In this article, it sounds like windowing's only use is in frequency analysis, as for example I am using it for making a windowed-sync FIR filter, and in this case the use of a window function (i chose the Blackman one) is to avoid riple in the frequency response of the FIR filter kernel. --SuperBleda 15:27, 19 August 2005 (UTC)
I still don't know, what is a window function? --anon
Whoever redid this, it's much much better now. 81.105.21.22 13:59, 7 April 2006 (UTC)
- I can't claim all the credit, but I did a lot of it. So on behalf of the whole team... thanks! --Bob K 07:18, 10 April 2006 (UTC)
[edit] DFT-even vs. Matlab
I'm a bit puzzled as to why the window functions given were not put in "DFT-even" form ( /N rather than /(N-1)). The reason to use "DFT-even" windows is covered in one of the articles's references. See pg 52 of the following:
Frederic J. Harris, On the use of Windows for Harmonic Analysis with the Discrete Fourier Transform, Proceedings of the IEEE, Vol.66, No.1, January 1978, pp 51-83.
--SAMerritt 10 May 2006
- I had the same question when I first arrived at this article. What I subsequently discovered is that Matlab defines the windows the way it's done here, not the "DFT-even" way. That seemed like a good enough reason to leave it as is. But in spite of that, I was the one who added the classic F.J.Harris reference, for historical reasons, if nothing else. --Bob K 04:03, 10 May 2006 (UTC)
[edit] The Comparison Graph
The comparison graph is great. The logarithmic frequency axis (in units of "DFT bins") is an excellent idea. It would also be helpful to label the axes. --Bob K 00:17, 10 September 2006 (UTC)
[edit] confusing wording
Can someone change this? In the third sentence of the following excerpt, it is unclear what "they" refers to (does it refer to window functions with low dynamic range, or window functions with poor resolution?): "This characteristic is sometimes described as low dynamic range. At the other extreme of dynamic range are the windows with the poorest resolution. And they are also poorest in terms of sensitivity." Lavaka 06:08, 8 January 2007 (UTC)
- Yes, very. I believe I have fixed it correctly, but I invite others to check me. Dicklyon 06:30, 8 January 2007 (UTC)
[edit] Bartlett/Triangle Window
Can someone check the equation for the triangle window? I've normally seen it as 1-abs((n-.5N)/.5N), or equivalently 1-abs((2n-N)/N). This page shows 1-abs((2n-N+1)/N)
Kelauder 06:05, 2 April 2007 (UTC)Kevin
- It's easy enough to verify by inspection that at the defined end indices of 0 and N-1 the values of the Barlett are 0 and of the triangle are 1/N; that is, the formulas work as expected. Your formula would work if the range was defined from 0 to N for Bartlett, or 1 to N-1 for triangle. But it's not. Dicklyon 06:35, 2 April 2007 (UTC)
