Equivalence/difference between firrcos and rcosdesign

Hi everybody,

I am currently working with legacy code, where firrcos was used to create a root-raised cosine filter. MATLAB suggest to use rcosdesign instead, as firrcos is deprecated. Looking for the equivalence of those two, I found a Mathworks document (<http://cn.mathworks.com/help/pdf_doc/comm/rn.pdf>) where they state the following code to generate two equal filters:

N = 16;
Fc = 1000;
R = 0.25;
Fs = 8000;
b2 = firrcos(N,Fc,R,Fs,'rolloff','sqrt');
b2n = rcosdesign(R, N/(Fs/Fc/2), Fs/Fc/2, 'sqrt');
b2n = b2n / max(b2n) * ((-1 ./ (pi.*(Fs/Fc/2)) .* (pi.*(R-1) - 4.*R)));

My question to you now is the following: Can anybody explain me why the normalization for b2n is necessary (the very last operation in the code above).

Thanks