fold_idx takes a dfidx object, includes the indexes as stand
alone columns, remove the idx column and return a data frame,
with an ids attribute that contains the informations about the
indexes. fold_idx performs the opposite operation.
Usage
unfold_idx(x)
fold_idx(x, pkg = NULL, sort = FALSE)
Value
a data frame for the unfold_dfidx function, a dfidx
object for the fold_dfidx function
Arguments
x
a dfidx object
pkg
if not NULL, this argument is passed to dfidx
sort
a boolean, whether the resulting dfidx object should
be sorted or not