似然函数如下:
function MLE(bbt1,bbt2,bbt3,bbt4,aalpha,pp1,pp2,aa,bb,cc,dd)
{
n=abs(y)
ut=y-x*(bbt1\bbt2\bbt3\bbt4)
zzt_1=randaepd(aalpha,pp1,pp2,n)
ww=aalpha*kep(pp1)+(1-aalpha)*kep(pp2)
zzt_2=zzt_1/ww
ee_aepd=E_aepd(aalpha,pp1,pp2)
vvar_aepd=Var_aepd(aalpha,pp1,pp2)
zzt=(zzt_2-ee_aepd)/sqrt(vvar_aepd)
Ezt=funEzt(zzt,n)
sigmat= funegarch_e( ut, Ezt, n, aa, bb, cc, dd)
alphass=aalpha*kep(pp1)/(aalpha*kep(pp1)+(1-aalpha)*kep(pp2))
e_aepd=E_aepd(aalpha,pp1,pp2)
var_aepd=Var_aepd(aalpha,pp1,pp2)
std_aepd=sqrt(var_aepd)
A1=0
A2=0
for(i=1; i<=n; i++)
{
if(zt(i,1)<=-e_aepd/std_aepd)
{
A1=A1-log(std_aepd/sigmat(i,1))-log(aalpha/alphass)-log(kep(pp1))+((abs((e_aepd+zt(i,1)*std_aepd)/(2*alphass)))^pp1)/pp1
}
else
{
A2=A2-log(std_aepd/sigmat(i,1))-log((1-aalpha)/(1-alphass))-log(kep(pp2))+((abs((e_aepd+zt(i,1)*std_aepd)/(2*(1-alphass))))^pp2)/pp2
}
}
}


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