STFT - DFT size of the bins

1. What are the bins of a DFT?
2. What is DFT size?
3. What is FFT bin size?
4. How do you calculate frequency bins?

What are the bins of a DFT?

The DFT output frequency bins correspond to the frequencies Fk=kFsN. With the more common frequency axis of half positive, half negative frequencies, the frequency bins for a DFT are given by f=np. arange(-Fs/2, Fs/2, Fs/N) . In this case, an fftshift of the DFT output is required before plotting the result.

What is DFT size?

If we look at the dimensions of the DFT result, we get 2+31*2 which is, again, 64 dimensions. Here is a visual representation of the matrix elements using the complex unit circle: The first row is the DC component or the bias. It only has real components.

What is FFT bin size?

The FFT size defines the number of bins used for dividing the window into equal strips, or bins. Hence, a bin is a spectrum sample , and defines the frequency resolution of the window. By default : N (Bins) = FFT Size/2.

How do you calculate frequency bins?

frequency bins are intervals between samples in frequency domain. For example, if your sample rate is 100 Hz and your FFT size is 100, then you have 100 points between [0 100) Hz. Therefore, you divide the entire 100 Hz range into 100 intervals, like 0-1 Hz, 1-2 Hz, and so on.