as.data.frame.labelled
                        as.data.frame method for labelled vectors
copy_labels             Copy variable and value labels
labelled                Create a labelled vector.
labelled_spss           Create a labelled vector with SPSS style of
                        missing values.
mean.labelled           Arithmetic mean for numeric labelled vectors
na_values               Get / Set SPSS missing values
nolabel_to_na           Recode values with no label to NA
remove_labels           Remove variable label, value labels and user
                        defined missing values
sort_val_labels         Sort value labels
to_character            Convert input to a character vector
to_factor               Convert input to a factor.
to_labelled             Convert to labelled data
val_labels              Get / Set value labels
val_labels_to_na        Recode value labels to NA
var_label               Get / Set a variable label
