User talk:Rafal.mazurek

A witamy, witamy... Więcej szczegółów będzie na żywo. Pozdro Zureks (talk) 12:41, 14 April 2008 (UTC)[reply]

File:Comparison_convolution_correlation.svg

Hi Rafal,

Thanks for your compliment and email:

Hello,
First of all, great job on all your contributions.
I think that there is an error in your illustration of Convolution - correlation. https://en.wikipedia.org/wiki/Convolution
You show "f" in row 1 and "g" in row 2 for convolution but the result in row 3 is produced with a mirror image of "g".
I think that perhaps "g" should be vertically mirror imaged (left <-> right).
Am I right? Let me know.
Cheers, Rafal

If you're referring to the leftmost of the 3 sets of graphs, it is indeed correct to mirror g to get f * g using the method shown.

Fig 13-5 in http://www.dspguide.com/ch13/2.htm has similar f, g and f * g.

Hope that helps, cmɢʟee⎆τaʟκ 00:53, 19 September 2014 (UTC)[reply]

P.S. Try http://wolframalpha.com/input/?i=Plot%5Bconvolve%28Piecewise%5B%7B%7B0%2Cx%3C-0.5%7D%2C%7B1%2C-0.5%3C%3Dx%3C%3D0.5%7D%2C%7B0%2Cx%3E0.5%7D%7D%5D%2CPiecewise%5B%7B%7B0%2Cx%3C-0.5%7D%2C%7B0.5-x%2C-0.5%3C%3Dx%3C%3D0.5%7D%2C%7B0%2Cx%3E0.5%7D%7D%5D%2Cx%2Cy%29%5D