(一)建立ARIMA模型
auto.arima(AA[,4])#识别最优阶数 arima1<-arima(AA[,4],order=c(0,1,3),method="ML") summary(arima1)
(二)建立GARCH模型
#GARCH模型
library(rugarch)
myspec=ugarchspec(variance.model=list(model="sGARCH",garchOrder=c(1,1),
submodel=NULL,external.regressors=NULL,variance.targeting=FALSE),
mean.model=list(armaOrder=c(1,1),include.mean=TRUE,archm=FALSE,archpow=1,
arfima=FALSE,external.regressors=NULL,archex=FALSE),
distribution.model="std")
garchfit=ugarchfit(myspec,data=SR_dayly,solver="solnp")
err=residuals(garchfit)
plot(residuals(garchfit),main="残差图")
plot(sigma(garchfit),main="波动率图")
#ARCH效应检验
for(i in 1:10){
print(ArchTest(err,lag=i))
}


(三)建立非对称GARCH模型
myspec=ugarchspec(variance.model=list(model="eGARCH",garchOrder=c(1, 1)),mean.model=list(armaOrder=c(0,0),include.mean=TRUE),distribution.model="std") fit=ugarchfit(myspec,data=S1,solver="gosolnp") summary(fit) plot(fit,which=12)#信息冲击曲线 plot(fit)


