MATLAB: [solved] difference between 2 spectrograms

Hello,

Here is the situation:

I have a dynamic system equipped with a vibration sensor.

this system has 2 configurations; I have 1 record of 10 minutes in each configuration

I plot spectrogram for each. So far, everything is fine

[s,f,t]=spectrogramspectrogram(data,hamming(wdw),overlap,[],10240);
[s2,f,t]=spectrogram(data2,hamming(wdw),overlap,[],10240);

Now I want to compare (make a difference) of these spectrograms, but

I can do s-s2, but before

I can't plot back the spectrogram from s

I tried several thing such as

im=imagesc(h/1000,(t/60),(abs((s')))) ; % tested with imag real and with image
colorbar
ylabel('Time (mins)');
xlabel('Frequency (kHz)');

but the result is different from

spectrogram(data,hamming(wdw),overlap,[],10240);

thank you for your answer

thank you for your answer, this is great help

here is the result

this is the best result I got so far. :D

some possible improvments

-the last time index is deleted

-Z data is different (but I will make comparisons, si not very important)

-the pscolor give a flat image, when spectrogram give a 3D I can rotate