[fpc-pascal] Good FFT example anywhere?

[Bo Berglund]

On Sun, 9 Apr 2017 11:22:00 +0300, Žilvinas Ledas
<zilvinas.ledas at dict.lt> wrote:

>
>On 2017-04-09 11:06, Bo Berglund wrote:
>> I am looking for some good example of FFT functions in pascal but it
>> seems like what Google serves up is rather old and refers to
>> Turbo-pascal and the like...
>> So maybe someone here knows about some open-source example of FFT
>> using FreePascal (or Delphi)?
>
>I was using attached unit some 7 years ago for various speech processing 
>purposes.
>
>Best regards,
>Žilvinas
>

I looked at it briefly and there are parts of it I don't understand,
for example:
NumberOfBitsNeeded, what purpose is this?
ReverseBits, does what and why?

I might have to run the code in a test program to see what is actually
going on. I did take the courses on Fourier transforms and the FFT
variant but that was a long time ago (like 40 years or so) so I am
rusty in that regard.

Generally (in reply to the other suggestions) I want a pure pascal
function so I can build it for the target platform, which will
probably end up being ARM and Linux (RPi3).
So no Intel stuff or Windows dll solutions...


-- 
Bo Berglund
Developer in Sweden