This performs the FFT on timedata and puts the result in freqdata.
timedata must have as many samples as specified with the len parameter while allocating the
F64 instance with F64.
freqdata must be large enough to hold len/2 + 1 F64Complex
frequency domain samples.
| this |
F64 instance for this call |
| timedata |
Buffer of the samples in the time domain |
| freqdata |
Target buffer for the samples in the frequency domain |