我正在尝试使用ugarchroll对我的arch模型进行回测,但是我收到此警告消息
“警告消息: 在.rollfdensity(spec = spec,data = data,n.ahead = n.ahead,Forecast.length = Forecast.length,:
存在未收敛的估计窗口...使用不同的求解器参数重新提交对象。”
这是我的代码
library(quantmod)
library(rugarch)
getSymbols("SPY")
rets=ROC(SPY$SPY.Close)
tgarch = ugarchspec(mean.model = list(armaOrder = c(1, 1)),
variance.model = list(model = "sGARCH"),
distribution.model = "std")
garchroll<-ugarchroll(tgarch, data = rets,n.start =500,
refit.window="window", refit.every =200)
答案 0 :(得分:0)
应用ROC()
时,第一个条目变为NA
。因此,当您应用rets
时,要从ugarchroll()
中排除它。因此,
garchroll <- ugarchroll(tgarch, data=rets[-1, ], n.start=500,
refit.window="window", refit.every=200)