Talk:Discrete Fourier transform

This is the talk page for discussing improvements to the Discrete Fourier transform article.
This is not a forum for general discussion of the article's subject.

Put new text under old text. Click here to start a new topic.
New to Wikipedia? Welcome! Learn to edit; get help.

Article policies

Find sources: Google (books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL

Archives: 1, 2, 3: 12 months

Mathematics High‑priority

	Mathematics portal This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.MathematicsWikipedia:WikiProject MathematicsTemplate:WikiProject Mathematicsmathematics
High	This article has been rated as High-priority on the project's priority scale.

Computing: Software / CompSci Mid‑importance

This article is within the scope of WikiProject Computing, a collaborative effort to improve the coverage of computers, computing, and information technology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.ComputingWikipedia:WikiProject ComputingTemplate:WikiProject ComputingComputing

Mid

This article has been rated as Mid-importance on the project's importance scale.

This article is supported by WikiProject Software (assessed as Low-importance).

This article is supported by WikiProject Computer science (assessed as Mid-importance).

Things you can help WikiProject Computer science with:

Here are some tasks awaiting attention:

Article requests :
- Requested articles/Applied arts and sciences/Computer science, computing, and Internet
Cleanup :
- Computer science articles needing attention
- Computer science articles needing expert attention
Copyedit :
- Computing
Expand :
- Computer science
Infobox :
- Computer science articles without infoboxes
Maintain :
- Timeline of computing 2020–present
Photo :
- Find pictures for the biographies of computer scientists (see List of computer scientists)
- Computing articles needing images
Stubs :
- Computer science stubs
Unreferenced :
- WikiProject Computer science/Unreferenced BLPs
Project-related :
- Tag all relevant articles in Category:Computer science and sub-categories with {{WikiProject Computer science}}

Are the equations for the dft and inverse dft swapped??

I have been working through the dft by hand, I have checked my math multiple times and have used wolfram alpha to provide more checking, but for the input x={1,2,3,4}

I keep getting X={10, -2+2i, -2, -2-2i}

and wolfram is giving me fft{1,2,3,4} = {5, -1-i, -1,-1+i}, but the ifft{1,2,3,4} = {5, -1+i, -1, -1-i}

This is only one half what I calculated by hand and so this is what makes me think the dft and inverse dft are swapped.

Also there might be something about dividing the result by 2, to be explored. 209.159.200.170 (talk) 20:33, 3 December 2022 (UTC)[reply]

Motivation

Please add a section explaining what this algorithm accomplishes. I passed an entire undergrad course on this topic, and still don't understand what the purpose of the transform is. Please help -- I'm not the only one! KatyKathinka (talk) 00:02, 23 April 2023 (UTC)[reply]

Link to subsection in Representation theory of finite groups no longer exists

"Further information: Representation theory of finite groups § Discrete Fourier transform" is missing 2A0C:5BC0:40:10C0:DE4A:3EFF:FE6D:C214 (talk) 14:57, 4 March 2024 (UTC)[reply]