resType
an optional character string specifying the type of
residuals to be used. If "response"
, the "raw" residuals
(observed - fitted) are used; else, if "pearson"
, the
standardized residuals (raw residuals divided by the corresponding
standard errors) are used; else, if "normalized"
, the
normalized residuals (standardized residuals pre-multiplied by the
inverse square-root factor of the estimated error correlation
matrix) are used. Partial matching of arguments is used, so only the
first character needs to be provided. Defaults to "pearson"
.
form
an optional one sided formula of the form ~ t
, or
~ t | g
, specifying a time covariate t
and, optionally, a
grouping factor g
. The time covariate must be integer
valued. When a grouping factor is present in
form
, the autocorrelations are calculated using residual pairs
within the same group. Defaults to ~ 1
, which corresponds to
using the order of the observations in the data as a covariate, and
no groups.