dfidx                   Data frames with indexes
idx                     Index for dfidx
idx_name                Get the name and the position of the index
                        column
methods.dfidx           Methods for dfidx
model.frame.dfidx       model.frame and model.matrix methods for dfidx
                        objects
munnell                 Productivity in the United States
unfold_idx              Fold and Unfold a dfidx object
