acv_arma {tsPI} | R Documentation |
Function acv_arma
computes a theoretical autocovariance function of ARMA process.
acv_arma(phi, theta, n)
phi |
vector containing the AR parameters |
theta |
vector containing the MA parameters |
n |
length of the time series |
vector of length n containing the autocovariances
## Example from Brockwell & Davis (1991, page 92-94)
## also in help page of ARMAacf (from stats)
n <- 0:9
answer <- 2^(-n) * (32/3 + 8 * n) /(32/3)
acv <- acv_arma(c(1.0, -0.25), 1.0, 10)
all.equal(acv/acv[1], answer)