**Deprecated**
`pffrGLS()` is deprecated. Use pffr() with
sandwich = "cluster" or sandwich = "cl2" instead.
pffrGLS(
formula,
yind,
hatSigma,
data = NULL,
ydata = NULL,
algorithm = NA,
method = "REML",
tensortype = c("ti", "t2"),
bs.yindex = list(bs = "ps", k = 5, m = c(2, 1)),
bs.int = list(bs = "ps", k = 20, m = c(2, 1)),
cond.cutoff = 500,
...
)Does not return; always errors with a deprecation message.
Ignored. The function always errors.