MATLAB: What is variable in spectrogram

Question

Hello,

I would like to know that if I use below code to STFT the data

>>[y,f,t,p] = spectrogram(data,256,250,256,Fs,'yaxis'); then what is the y and p? when I understanded that f is frequency and t is time.

Thank you

Answer 1

y is short-time Fourier transform of the input signal p is power spectral density (PSD)