signal and system by using MATLAB

I am currently using(discrete wavelet transform DWT to perform feature extraction of EEG signals. The code that I have used is just

load('chb01_03_edfm.mat') plot(val(1,:))

please help, How I can complete the code to get signal like this figure

Fig.7 Variance comparison between A and E type signal Fig.8 Maximum value comparison between A and E type signal Fig.9 Minimum value comparison between A and E type signal Fig.10 Entropy comparison between A, D and E type signal Fig.7 Variance comparison between A and E type signal Fig.8 Maximum value comparison between A and E type signal Fig.9 Minimum value comparison between A and E type signal Fig.10 Entropy comparison between A, D and E type signal