Not sure about my fitness function works

Hi, I want to calculate coefficients for Farrow structure and I want to use ga as I saw in some papers. But I'm not sure that I wrote fitness function well. The aim is minimazing the frequency response respect to ideal one, in particular minimazing magnitude and phase for each value of discretized frequency and fractional delay. Here I post the code about fitness function.

function error = fitness_farrow( h )

M =  3;

Nh = 10;

for m=1:M+1    

hd(m,:) = h((m-1)*Nh+m:m*Nh+m);     % put variables h in matrix form MxN

end

alpha = 0.8;

wl = 0:0.1:alpha*pi;

Q = 1000;

dpq = (0:1:Q-1)/Q;

error = 0;

for i=1:length(dpq)

      for u=1:length(wl)

          sum_m = 0;

          for m=1:M+1

              sum_n = 0;

              for n=1:Nh+1

                           coeff = hd(m,n).*exp(-1i* wl(u)*(n-1)) ;

                           sum_n = sum_n +  coeff;

              end

                       coeff_m = sum_n .* dpq(i)^(m-1);

                       sum_m = sum_m + coeff_m;

          end

        error_a = abs( abs(sum_m) - 1 ) ;

        error_p = abs( dpq(i) - angle(sum_m)/wl(u) );

        obj_fun = error_a + error_p;

        error = error + obj_fun ; 

       end

end

end