[R] FFT Normalization Documentation

[Martin Maechler]

>>>>> Hiroyuki Kawakatsu <hkawakat at gmail.com>
>>>>>     on Thu, 5 Feb 2015 12:40:28 +0000 writes:

    > On 2015-02-05 Martin Maechler wrote:
    > [...]
    >> Both a definition of the DFT (in LaTeX or directly as \deqn{}{}) which
    >> matches *our* fft(), and an extended commented example (ca 20 lines,
    >> rather than ca 100 lines!) would be welcome additions.
    > [...]

    > Here is a previous attempt:

    > https://stat.ethz.ch/pipermail/r-devel/2008-June/049807.html

    > It fell on deaf ears so someone could improve on it. I still
    > google this page when I have to remind myself what fft()
    > is doing.

"deaf ears" is clearly too strong here (my wife really having 99% deaf ears..),
but indeed, it is a pity that this was completely overlooked and
never taken up.

I'll do so now.
Martin