各位达人,小弟初次用EVIEWS编程,希望编写出下面的模型
y = C(1)*GARCH + C(2) + C(3)*y(-1) + C(4) * y(-1) *GARCH
GARCH = C(4) + C(5)*RESID(-1)^2 + C(6)*RESID(-1)^2*(RESID(-1)<0) + C(7)*GARCH(-1)
小弟按照EVIEWS的帮助,模仿了一个。。。但是很多错误,最后也不知道怎么写下去,还望指教
'change path to program path
%path = @runpath +"../data/"
cd %path
' load workfile
load test
series y = 100*dlog(price)
sample s0 1 1
sample s1 2 1010
smpl s1
' declare coef vectors to use in ARCH likelihood
coef(4) omega = .1
coef(4) alpha = .1
coef(1) mu = .1
' get starting values from T-GARCH(1,1,1)
equation eq1. arch(thrsh=1,archm=var,deriv=aa) y c y(-1)
omega(1) = eq1.C(1)
omega(2) = eq1.C(2)
omega(3) = eq1.C(3)
omega(4) = eq1.C(4)
alpha(1) = eq1.C(5)
alpha (2) = eq1.C(6)
alpha (3) = eq1.C(7)
alpha (4) = eq1.C(8)
'这里把所有的GARCH参数都提取了。。。但是不知道有没有用。。。
' set presample values of expressions in logl
smpl s0
series sig2 = mu(1)
' set up GARCH likelihood
logl ll1
ll1.append @logl logl
ll1.append res = y - omega(1)*sig2 - omega(2) - omega(3) *y(-1) - omega(4)*y(-1)*sig2
ll1.append sig2 = alpha (1)+ alpha (2)*res^2 + alpha (3)*res^2*(res(-1)<0) +alpha(4)*sig2(-1)
ll1.append logl =
'最后最大似然应该如何写呢?
' estimate and display results
smpl s1
ll1.ml(showopts, m=1000, c=1e-5)
show ll1.output
谢谢版上的达人~~