R/swap_by_value.R

In peterhurford/surveytools2: Surveytools2 is a collection of R functions that make working with dplyr on survey analysis just a little bit better. Inspired by dplyr and my previous surveytools package.

#' Renames values within a dataframe based on a list of swaps to make.
#' Useful for imputation.
#'
#' @param df data frame.  The data to be transformed.
#'
#' @param variable character. The name of the variable in df where the replacement occurs.
#'
#' @param swap_list list. A list mapping current values to what they should be.
#' e.g., to replace all instances of "dog" with "cat", use
#' \code{list('dog' = 'cat')}
#'
#' @param grep logical. Should values be searched by grep (grep = TRUE) or just found by full name (default)?
#'
#' @export
swap_by_value <- function(df, variable, swap_list, grep = FALSE) {
  if ("" %in% names(swap_list)) {
    stop("Your swap_list is misconfigured. All elements of the swap_list must be named.")
  }
  if (length(variable) > 1) {
    for (var in variable) {
      df <- swap_by_value(df, var, swap_list, grep = grep)
    }
  } else {
    if (isTRUE(grep)) {
      for (swap in names(swap_list)) {
        df[grepl(swap, df[[variable]]) & !is.na(df[[variable]]), variable] <- swap_list[[swap]]
      }
    } else {
      for (swap in names(swap_list)) {
        df[df[[variable]] == swap & !is.na(df[[variable]]), variable] <- swap_list[[swap]]
      }
    }
  }
  df
}