Re-exports nlme::corARMA from the nlme package.
corARMA(value, form, p, q, fixed)numeric vector of parameter values
a one-sided formula of the form ~ t, ~ 1 | g, or ~ t | g,
specifying a time covariate t, a grouping factor g, or both.
When no time covariate is specified, the row order of the data within each group is assumed to
represent the chronological order of measurements.
non-negative integer specifying the autoregressive order
non-negative integer specifying the moving average order
unused
In the original nlme::corARMA function, a covariate t must be an integer class.
In pwr4exp, t can also be a factor class, which is then converted to an integer internally for chronological order.
The class of t in the model formula, if present, is not converted. For example, a time covariate can be fitted as a factor
in the model formula, whereas it is converted to an integer in the correlation formula.
corClasses See nlme::corARMA for original documentation.