FFT analysis for series of different length

1. How do you calculate FFT length?
2. What is transform length in FFT?
3. What are the limitations of FFT?

How do you calculate FFT length?

FR = Fmax/N(Bins)

FR = 22050/1024 ≃ 21,53 Hz. Basically, the FFT size can be defined independently from the window size. In AS, the FFT size can only be calcularted proportionnaly to the window size, in order to preserve a relevant relationship between both parameters.

What is transform length in FFT?

The execution time of fft depends on the length of the transform. Transform lengths that have only small prime factors result in significantly faster execution time than those that have large prime factors. In this example, the signal length L is 44,101, which is a very large prime number.

What are the limitations of FFT?

A disadvantage associated with the FFT is the restricted range of waveform data that can be transformed and the need to apply a window weighting function (to be defined) to the waveform to compensate for spectral leakage (also to be defined). An alternative to the FFT is the discrete Fourier transform (DFT).