Timeline for Show how to do FFT by hand
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| S Sep 25, 2019 at 20:53 | history | suggested | CommunityBot | CC BY-SA 4.0 |
Initial FFT of [3, 1, 0, 0] is incorrect in that 2nd/4th results are switched - it should be [4, 3+i, 2, 3-i] rather than [4, 3-i, 2, 3+i], Ultimately this does not impact the final answer but it throws off people who are tyring to understand FFT. Extra added for 6 char min edit
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| Sep 21, 2019 at 18:39 | review | Suggested edits | |||
| S Sep 25, 2019 at 20:53 | |||||
| Dec 14, 2016 at 20:29 | comment | added | Yuval Filmus | @BobbyLee I encourage you to read some literature on FFT. | |
| Dec 14, 2016 at 20:15 | comment | added | Bobby Lee | How do these formulas for $X_{0,2}$ and $X_{1,3}$ extend to higher degrees? Do the plus/minus signs just keep flipping? For example what would it be for $X_{0,2,4}$ ? | |
| Dec 6, 2014 at 2:02 | comment | added | Aage Torleif | Why do you use the even coefficients twice? 3,3 -> 3,3,3,3. -> 3+1, 3-i, 3+-1,3--i ? | |
| S Nov 24, 2014 at 2:47 | history | suggested | Abhinav Vishak Iyappan | CC BY-SA 3.0 |
Mathematical mistakes in the calculation of the fourier transform of the first polynomial.( Mistake in calculation of 2-pt DFT ) and in twiddle factor substitution )
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| Nov 23, 2014 at 18:14 | review | Suggested edits | |||
| S Nov 24, 2014 at 2:47 | |||||
| Oct 23, 2013 at 19:46 | comment | added | Yuval Filmus | I gave the formulas: $X_{0,2} = (E_0 \pm O_2)/2$, $X_{1,3} = (E_1 \mp i O_1)/2$, where $E_0,E_1$ ($O_1,O_2$) is the inverse transform of the even (odd) coefficients, obtained through the formula $x,y \mapsto (x+y)/2,(x-y)/2$. Please look at the answer again - all the calculations are there. | |
| Oct 23, 2013 at 18:11 | comment | added | lars | how did you arrive at 6,2 6, 2? | |
| Oct 21, 2013 at 14:19 | vote | accept | lars | ||
| Oct 21, 2013 at 1:34 | history | answered | Yuval Filmus | CC BY-SA 3.0 |