partial autocorrelation within groups

[Jack Lewis <jl7001@axe.humboldt.edu>]

With models fitted by lme and gls, ACF.lme() and ACF.gls() give the
empirical autocorrelation function of within-groups residuals [nlme
package version 3.3], but not the partial autocorrelations.  Yet both
are needed for ARMA model identification.  Has anyone written a function
to calculate the partial autocorrelations?

Thanks,

Jack Lewis