MATLAB: Writing fmincon funtion in matlab

Question

Hi, Can someone please elp me to do the following optimization problem unsin FMINCON . I have a hard time writng the function that is used in FMINCON.

Thanks

clc;
clear;
p=1;
a0 = 0.1; a1 = 0.4; 
epsi=zeros(3000,1);
simsig=zeros(3000,1);
for i = 1:3000
                 if (i==1) 
                     simsig(i) = a0/(1-a1);
                     s=(simsig(i))^0.5;
                     epsi(i) = normrnd(0,1) * s;
                 elseif (i==2)
                     epsi(i)=epsi(1);
                 else                     
                     simsig(i) = a0+ a1*(epsi(i-1))^2;
                     s=(simsig(i))^0.5;
                     epsi(i) = normrnd(0,1) * s;
                 end
end
yt1=epsi.^2;
ytinitial=yt1(2001:3000);
y=yt1(2001:3000);
len = length(ytinitial);
C = zeros(len,p+1);
C(:,1) = 1; %The first column is for a0
for i = 1:p %Then create shifted columns ( p in number ) for a 
       C(1+i:len,1+i) = y(1:len-i,1);     
end
options =optimset('Display','off','LargeScale','off');
coef = lsqlin(C,ytinitial,[0 1],1,[],[],[0;0],[1;1],[],options);
alpha0 =coef(1);
ar1=coef(2);

Answer 1

fun=@(x) norm(C*x(:)-ytinitial)^2;