alpha_feature.m

function feature = alpha_feature(EEG)
    
    % constants
    alpha = 7 : 12;
    left_channels = 1 : 4;
    right_channels = 11 : 14;
    
    % left mean alpha power for every channel
    left_alpha_power_avg = 0;
    for chan = left_channels
        pxx = pwelch(EEG.data(chan, :));
        left_alpha_power_avg = left_alpha_power_avg + mean(pxx(alpha));
    end
    left_alpha_power_avg = left_alpha_power_avg / length(left_channels);
    
    % right mean alpha power for every channel
    right_alpha_power_avg = 0;
    for chan = right_channels
        pxx = pwelch(EEG.data(chan, :));
        right_alpha_power_avg = right_alpha_power_avg + mean(pxx(alpha));
    end
    right_alpha_power_avg = right_alpha_power_avg / length(right_channels);
    
    feature = [log(left_alpha_power_avg), log(right_alpha_power_avg)];

end