Modification of objective function for optimization without using matlab function

Dear all,

I am writting a code like

syms y, z

N=input('length of the data= ');

x = constellation(randi([1 4],1,N)); %QPSK data(constellation is already declared)

hr=(randn(1)+j*randn(1));

hr1=(randn(1)+j*randn(1));

r=z*(hr.*x+hr1.*y);

xt = x;

xt(2:2:end) = 0;

rr = r;

rr(1:2:end) = 0;

rl=6*rr+z*n; % n is random value

for ii=1:N

p(ii)= mean(norm(xt(ii)-rl(ii))^2);

end

c_3=sum(p);

obj=matlabFunction(c_3);

This code is running ,but I don't want to use matlabfunction. How I can write(modify) my objective function directly according to my code which will be useful for optimization ?

Thanks in advance