MATLAB: Sum of coefficients less than 1

time series

Can someone please modify the following code so that it has a constraint that the sum of ar1 and ar2 is less than one.
Thanks
clc;
clear;
m=2;
a0 = 0.1; a1 = 0.2; a2=0.15;
epsi=zeros(3000,1);
simsig=zeros(3000,1);
for i = 1:3000
                 if (i==1) 
                     simsig(i) = a0/(1-a1-a2) ;
                     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+a2*(epsi(i-2))^2;
                     s=(simsig(i))^0.5;
                     epsi(i) = normrnd(0,1) * s;
                 end
end
yt1=epsi.^2;
ytlast=epsi(3000)^2;
ytlast2=epsi(2999)^2;
ytinitial=yt1(2001:3000);
yt = yt1(2003:3000);
ytlag1= yt1(2002:2999);
ytlag2= yt1(2001:2998);
a =ones(1000-m,1);
x = [a,ytlag1,ytlag2];
opts = optimset('lsqnonneg');
opts.LargeScale = 'off';
opts.Display = 'none';
coef = lsqnonneg(x,yt);
alpha0 =coef(1);
ar1=coef(2);
ar2= coef(3);

Best Answer

Do you have the optimization toolbox? LSQNONNEG cannot handle constraints.
Also, please format your code when you post. It makes it easier to read code. You can select your code and use the '{}Code' button.
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