Basic HTML version of Foils prepared April 22 2000

Foil 19 What's Going On with DIT/DIF II

From Parallel FFT and use in PDE Solvers Computational Science Class CPS615 -- Winter Semester 2000. by Geoffrey C. Fox
1 Here of course vector size N = 2d
2 For DIT, the first step, manipulates (in "butterfly fashion"), the lowest component m0 for time and creates the highest binary digit kd-1 for frequency domain.
3 Note that most FFT implementation overwrite f[m] by its FFT GN(k,f) as they go along
4 This implies that we start with f(m) where m labeled like
5 And end with that start of a recursive FFT labeled like:
6 Note characteristic bit reversal in storage of GN(k,f)
7 "Wrong End"
in Table To:

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