spectrogram having as input a vector F

The variant of spectrogram with an input vector F?

[S,freq,time, P]= spectrogram(x, 128,64, 2:0.1:30, 512)?

The estimation of S (and P) are achieved using what method? What is the principle behind the calculations ?

Answer 1

[Asvin Kumar]

The spectrogram function computes the Short-Time Fourier Transform (STFT).

The STFT will be computed at frequencies (in Hz) specified by the values in ‘f’ when called with the form:

[s,f,t,p] = spectrogram(x,window,noverlap,f,fs) 

The principal in this form is the same as the principal in all the other forms of the function.

[Ana Maria Tome]

Thank you very much. Meanwhile I figure out that this form uses Goertzel algorithm or czt transform.