老师是专攻realized garch的金融计量老师··· 课后要求我们用matlab实现realized garch··· 请问realized garch到底和garch模型有什么区别，然后function code和garch有什么区别吗？
附 garch funciton code：
function [param,outs] = garch11_m(r10y,r3m)

%% optimization
options = optimset('Algorithm','interior-point','Display','iter');
%param0 = [0.1;0.15;0.75;0.1;0.8;0;1];
param0 = [0.0001;0.01;0.95;-0.305;0.95;-0.59;1]; %local minnum

A = [0,1,1,0,0,0,0];
b = 1;
lb = [0,0,0,-inf,-inf,-inf,-inf]';
ub = [inf,1,1,inf,inf,inf,inf];
[param,ll,exitflag,~,~,grad,hessen] = fmincon(@neglogl,param0,A,b,[],[],lb,ub,[],options,r10y,r3m);

%% output
if nargout == 2
    outs.cov = inv(hessen);
    outs.exitflag = exitflag;
    outs.ll = -ll;
    outs.grad = -grad;
    outs.hessen = -hessen;
   
    alpha0 = param(1);
    alpha1 = param(2);
    beta1 = param(3);
    gamma0 = param(4);
    gamma1 = param(5);
    phi = param(6);
    rho = param(7);
    n = length(r10y);
    sigma = zeros(n,1);
    mu = zeros(n,1);
    for t = 2:n
        sigma(t) = alpha0 + alpha1*mu(t-1) + beta1*sigma(t-1);
        mu(t) = gamma0 + gamma1*r3m(t) + phi*sigma(t)^(rho/2);
    end
    outs.mu = mu;
    outs.sigma = sigma;
   
end

end

%% define the objective function
function ll = neglogl(param,r10y,r3m)
alpha0 = param(1);
alpha1 = param(2);
beta1 = param(3);
gamma0 = param(4);
gamma1 = param(5);
phi = param(6);
rho = param(7);
n = length(r10y);
sigma = zeros(n,1);
mu = zeros(n,1);
mu(1) = r10y(1);
for t = 2:n
    sigma(t) = alpha0 + alpha1*mu(t-1) + beta1*sigma(t-1);
    mu(t) = gamma0 + gamma1*r3m(t) + phi*sigma(t)^(rho/2);
end
ll = -mean(log(pdf('norm',r10y(2:end),mu(2:end),sqrt(sigma(2:end)))));
end