generate the spectrogram of one dimensional signal

genSpectrogram.m

%%reference: http://www.mathworks.com/help/signal/ref/spectrogram.html

dat = load('/media/dl/data1/kaggle_eeg_2016/train_1/1_1_1.mat');
dat = dat.dataStruct.data;
dat = dat(:, 1);

Nx = length(dat); %sample number
nsc = floor(Nx/600); %number of signal sections
nov = floor(nsc/2); %overlap between adajacent windows
nff = max(256,2^nextpow2(nsc)); %number of samples to compute the FFT

[S, F, T, P] = spectrogram(dat,hamming(nsc),nov,nff);
figure;
imshow((P))