Spectrogram - How to divide signal ?

Hello

I have a signal 120 seconds long with sampling frequency 1KHz. How do I compute the spectrogram with 120 time segments ? Each segment 1000 samples. The code below gives me t = 136 not 120

segments = 120;     
windowsize = 1000;
nfft = 1000;

[S,F,T,P] = spectrogram(data,windowsize,segments,nfft,Fs);

Answer 1

[Rick Rosson]

The third input argument of spectrogram expects the number of samples to overlap each window, not the number of segments. Please try:

   winSize = 1000;
   overlap = 0;
   fftSize = winSize;

   [S,F,T,P] = spectrogram(data,winSize,overlap,fftSize,Fs);

It is common practice, however, to set the overlap to half of the window size:

   overlap = floor(winSize/2);

but it is not required if you don't want it.

HTH.