Talk:Rader's FFT algorithm

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Latest comment: 1 year ago by 128.54.13.249 in topic Time complexity without zero-padding

Hey, does anyone have a ___location for where this conference took place. The citation reads:

C. M. Rader, "Discrete Fourier transforms when the number of data samples is prime," Proc. IEEE 56, 1107–1108 (1968)

but I don't see a ___location.

Proceedings of the IEEE is a journal, not a conference. See here. —Steven G. Johnson 21:54, 2 April 2007 (UTC)Reply

Finding the generator (g)

The algorithm explained in the article uses a generator - g - of the modulo N multiplication group, known to exist from number theory. However, no algorithmic way is mentioned to find such a generator. Is there an efficient way to do this? 2A02:8109:9340:112C:FD62:EAA0:5CCE:62F8 (talk) 01:01, 9 February 2015 (UTC)Reply

Since the generators are extremely common, just exhaustive testing will turn one up pretty quickly, although there are slightly faster algorithms than this. (See e.g. Donald E. Knuth, The Art of Computer Programming, vol. 2: Seminumerical Algorithms, 3rd edition, section 4.5.4, p. 391 (Addison–Wesley, 1998).) I'll add a link. (It's also discussed in Primitive root modulo n#Finding primitive roots.) — Steven G. Johnson (talk) 18:03, 24 October 2017 (UTC)Reply

So who is "Rader"?

This article isn't very clear who the "Rader" in question is. If it's Rader's FFT algorithm, then it should say who it was named after.--Varkman (talk) 05:16, 20 November 2015 (UTC)Reply

Note that this has been fixed (it is Charles M. Rader, a well-known figure in the signal-processing community). — Steven G. Johnson (talk) 17:52, 24 October 2017 (UTC)Reply

Time complexity without zero-padding

Without zero-padding, the article states that the worst case requires O(N2) time. But each step of the recursion halves N, therefore isn't it still O(N log N) time? — Preceding unsigned comment added by Raysphere24 (talkcontribs) 08:18, 3 January 2021 (UTC)Reply

Agree. 128.54.13.249 (talk) 22:14, 9 November 2023 (UTC)Reply