Compute variances of autocorrelations under ARCH-type hypothesis
nvarOfAcfKP.Rd
Compute variances of autocorrelations under ARCH-type hypothesis.
Usage
nvarOfAcfKP(x, maxlag, center = FALSE, acfscale = c("one", "mom"))
Arguments
- x
time series.
- maxlag
a positive integer, the maximal lag.
- center
-
logical flag, if FALSE, the default, don't center the time series before squaring, see Details.
- acfscale
-
character string, specifying what factor to use for the autocovariances.
"one"
stands for \(1/n\),"mom"
for \(1/(n-k)\), where \(n\) is the length ofx
and \(k\) is lag.
Details
nvarOfAcfKP
computes estimates of \(n\) times the variances
of sample autocorrelations of white noise time series. It implements
the result of (Kokoszka and Politis 2011)
which
holds under weak assumptions. In particular, it can be used to test if
the true autocorrelations of a time series are equal to zero in GARCH
modelling.
References
Kokoszka PS, Politis DN (2011). “Nonlinearity of ARCH and stochastic volatility models and Bartlett's formula.” Probability and Mathematical Statistics, 31(1), 47--59.