R/likert_transform.R

In samueltobler/behavdata: Behavioral Data Preprocessing and Analysis

#' Transforming Likert Scale Answers in numerical operators
#'
#' @param
#' @keywords Likert; numerical; transformation
#' @export
#' @examples
#' @import sjmisc
#'

likert_transform <- function(data, type = "dataframe", name = "", lang = "de", other = c("NA"), export = TRUE) {
  
  require(sjmisc)
  
  if (type == "vector") {data <- as.data.frame(data)} else {}
  
  if (lang == "de") {
  
  for (i in 1:dim(data)[1]) {
    for (j in 1:dim(data)[2]) {
      
      if (is_empty(data[i,j]) == TRUE) {data[i,j] = "NA"}
      
      if (data[i,j] == "Trifft nicht zu") {data[i,j] = 1} 
      if (data[i,j] == "Trifft eher nicht zu") {data[i,j] = 2} 
      if (data[i,j] == "Teils-teils") {data[i,j] = 3} 
      if (data[i,j] == "Trifft eher zu") {data[i,j] = 4} 
      if (data[i,j] == "Trifft zu") {data[i,j] = 5} 
    }
  }
 
  }
  
  if (lang == "en") {
    
    for (i in 1:dim(data)[1]) {
      for (j in 1:dim(data)[2]) {
        
        if (is_empty(data[i,j]) == TRUE) {data[i,j] = "NA"}
        
        if (data[i,j] == "Strongly disagree") {data[i,j] = 1} 
        if (data[i,j] == "Disagree") {data[i,j] = 2} 
        if (data[i,j] == "Neither agree nor disagree") {data[i,j] = 3} 
        if (data[i,j] == "Agree") {data[i,j] = 4} 
        if (data[i,j] == "Strongly") {data[i,j] = 5} 
      }
    }
    
  }

  
  if (other[1] != "NA") {
    
    for (l in 1:length(other)) { 
    for (i in 1:dim(data)[1]) {
      for (j in 1:dim(data)[2]) {
        
        if (is_empty(data[i,j]) == TRUE) {data[i,j] = "NA"}
    
        if (data[i,j] == other[l]) {data[i,j] = l} 
        }
      }
    }
    
  }
  
  
  
  if (export == TRUE) {
    
    if(dir.exists(file.path("CSV")) == TRUE) {} else {dir.create("CSV")}
    
    nametable <- paste("CSV/LikertTransform_", name,".csv", sep = "")
    write.table(data, nametable, sep = ";", col.names = FALSE, row.names = FALSE)
    print("Your answers have been saved in a CSV file.") 
    
  }
  
  outputlist <- list("data" = data)
  
}