FFT shows systematic deviations from analytical result

1. What does the FFT show?
2. What is the result of FFT?
3. What are the limitations of FFT?
4. How accurate is FFT?

What does the FFT show?

The FFT shows the two distinct frequencies of the individual pipes. These illustrations show the essential nature of the FFT. For a sine wave with a single frequency, the FFT consists of a single peak.

What is the result of FFT?

The FFT function returns a result equal to the complex, discrete Fourier transform of Array. The result of this function is a single- or double-precision complex array.

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).

How accurate is FFT?

Discrete Fourier transforms computed through the FFT are far more accurate than slow transforms, and convolutions computed via FFT are far more accurate than the direct results. However, these results depend critically on the accuracy of the FFT software employed, which should generally be considered suspect.