1. The code in the rmgarch.tests folder is up to date. The code below that you quote is an outdated example and not from the rmgarch.tests folder but from the help page for cgarchsim (which I should update anyway when I find the time). Please only use the examples from the folder indicated (there are plenty!).

2. You are free to look inside the returned object or work with the extractor functions provided.
e.g.
slotNames(sim1)
names(sim1@msim)

3. This is the 1-ahead simulation. Why would you expect the covariance and correlation to be uncertain? This is a non-bayesian setup which means that parameter uncertainty is not taken into account and hence the 1-ahead conditional covariance is given by the GARCH type dynamics without recourse to any uncertainty etc.

-Alexios

On 08/05/2012 17:53, Alex Fei wrote:
Thank you Alexios for quick reply!! The files in the 'rmgarch.tests' folder
gave me a lot of help.

Can I do 1-step ahead forecasting using GARCH-Copula with the help of
rmgarch package? for example I need to get the returns of each assets and
their covariance at T+1 based on the parameters estimated using in-sample
data until T?

I followed your Example in the help of cgarchsim. Please correct me if I am
wrong:
1) the (mean) forecast returns should be the simmean1 in your example
2) I think rcov(sim1) only report the 1st cov out of 3500 simulations. Then
how to get the mean forecast cov?

I think the Example in ?cgarchsim has a copula of errors, although none of
them is serious:
spec = cgarchspec(uspec = multispec( replicate(3, uspec) ), VAR = TRUE,
VAR.opt = list(lag = 1, lag.max = 4,
lag.criterion = c("AIC", "HQ", "SC", "FPE"), external.regressors = NULL),
dccOrder = c(1,1), distribution.model = list(copula = c("mvnorm"), method =
c("ML"),
time.varying = TRUE, transformation = "parametric"), start.pars = list(),
fixed.pars = list())

VAR.opt = list(lag = 1, lag.max = 4,  lag.criterion = c("AIC", "HQ", "SC",
"FPE"), external.regressors = NULL) need to be lag = 1, lag.max = 4,
lag.criterion = c("AIC", "HQ", "SC", "FPE"), external.regressors = NULL

sim1 = cgarchsim(fit1, n.sim = 1, n.start = 0, m.sim = 3500, presigma =
tail(sigma(fit1), 1),
startMethod = "sample", preR = preR, prereturns = tail( as.matrix(Dat), 4),
preresiduals = tail(residuals(.fitlist), 1),rseed = 1:3500)

if I use prereturns = tail( as.matrix(Dat), 4) , it will report error. So
instead, I use prereturns = tail( as.matrix(Dat), 1)

forcmean = round( rgarch:::varxforecast(X = Dat, Bcoef =
fit1@mfit$vrmodel$Bcoef, p = 4,
                                out.sample = 0, n.ahead = 1, n.roll = 0, 
mregfor = NULL), 5)

the rgarch package is offline. So can you suggest another way for this?

Thank you again!

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