Compute the theoretical autocorrelation function for an ARMA process.
ARMAacf_cpp(ar,ma,lag_max)x A matrix listing values from 1...nx in one column and 1...1, 2...2,....,n...n, in the other
A vector of length p containing AR coefficients
A vector of length q containing MA coefficients
A unsigned integer indicating the maximum lag necessary
James J Balamuta
This is an implementaiton of the ARMAacf function in R. It is approximately 40x times faster. The benchmark was done on iMac Late 2013 using vecLib as the BLAS.