writing correct fitness function for GA

Hi Friends, Please can anyone help me correct this GA code to minimimize measured and predicted results to extract the three parameters.I got an error message when I run it on matlab GA tool. function Ap = insertionlossnew(x) L1=3; Zcd1=x(1); L2= 24; Zcb=x(2); L3=3; Zcd2=x(3); Ap=eye(1); for f=[1 4 8 10 16 20 25 31.25 62.5 100 200 250 300 400 500]; Ap = (f*((L1)*(Zcd1)+(L2)*(Zcb)+(L3)*(Zcd2))); end Am=[20.3 23.4 24.6 25.3 23.4 26.4 27.5 22.9 23.7 29.8 31.3 32.8 27.9 25.8 35.6]; Y1=sqrt(sum(Ap-Am)^2); Y2=mean(Am,15); disp(Y2); Y3=sqrt(sum(Am-Y2)^2); Y4=Y1/Y3; Y=(1-Y4)*100; disp(Y);