% mean of the dB value% dB --> linear --> mean --> dBfunction y = average3(x,average_factor)y = nan(floor(length(x)/average_factor),1);for k = 1:floor(length(x)/average_factor)    y(k) = ...        10*log10(mean(10.^(double(x((k-1)*average_factor+1:k*average_factor))/10)));end