Use exponentially weighted moving-average method to
compute the volatility matrix
Usage
EWMAvol(rtn, lambda = 0.96)
Arguments
rtn
A T-by-k data matrix of k-dimensional asset returns, assuming the
mean is zero
lambda
Smoothing parameter. The default is 0.96. If lambda is negative, then the multivariate Gaussian likelihood is used to estimate the smoothing parameter.
Value
Sigma.t
The volatility matrix with each row representing a volatility matrix
return
The data
lambda
The smoothing parameter lambda used
References
Tsay (2014, Chapter 7). Multivariate Time Series Analysis with
R and Financial Applications. John Wiley. Hoboken, NJ.