11 May
2021
11 May
'21
1:21 a.m.
On Mon, May 10, 2021 at 11:00:10PM +0200, Jeanette C. wrote:
The output can be read as two halves:
up to half the array:
output[k] = real[k] the real part of the FFT
The second half:
output[size -k] = imaginary[k], the imaginary/complex part of the FFT
The output shows 0 for the first to real values, but the same strength for
the first two imaginary parts. Is this to be expected?
Yes. The sin() waves appear in the imaginary part, if you would
have used cos() instead that would show up in the real part.
In general you will have both, and
* the amplitude is hypot (real, imag).
* the phase is atan2 (imag, real).
Ciao,
--
FA