R/values2labels.R

In expss: Tables, Labels and Some Useful Functions from Spreadsheets and 'SPSS' Statistics

#' Replace vector/matrix/data.frame/list values with corresponding value labels.
#' 
#' \code{values2labels} replaces vector/matrix/data.frame/list values with
#' corresponding value labels. If there are no labels for some values they are
#' converted to characters in most cases. If there are no labels at all for
#' variable it remains unchanged. \code{v2l} is just shortcut to \code{values2labels}.
#' 
#' @param x vector/matrix/data.frame/list
#' @return Object of the same form as x but with value labels instead of values.
#'  
#' @seealso \link{names2labels}, \link{val_lab},  \link{var_lab}
#' @examples
#' data(mtcars)
#' var_lab(mtcars$mpg) = NULL
#' val_lab(mtcars$am) = c(" automatic" = 0, " manual" =  1)
#' 
#' summary(lm(mpg ~ ., data = values2labels(mtcars[,c("mpg","am")])))
#' @export
values2labels = function(x){
    UseMethod("values2labels")
}

#' @export
values2labels.default = function(x){
    vallab = val_lab(x)
    if(is.null(vallab)) return(x)
    res = names(vallab)[match(x,vallab,incomparables = NA)]
    res_na = is.na(res)
    if(any(res_na)) res[res_na] = x[res_na]
    var_lab(res) = var_lab(x)
    res
    
}

#' @export
values2labels.matrix = function(x){
    res = values2labels.default(x)
    res = matrix(res, nrow = nrow(x), ncol = ncol(x))
    res
    
}

#' @export
values2labels.data.frame = function(x){
    values2labels.list(x)
}


#' @export
values2labels.list = function(x){
    for (each in seq_along(x)){
        x[[each]] = values2labels(x[[each]])
    }
    x
}


#' @export
#' @rdname values2labels
v2l = values2labels