R/natoempty.R

In debarros/dbTools: Functions From de Barros

#' @title NA to Empty
#' @description Converts all NA's in a character vector to empty values
#' @param x A character vector
#' @return A character vector contain all of non NA elements of \code{x}
#' @examples
#' ex1 = LETTERS[1:10]
#' ex2 = c(NA, letters, NA)
#' ex3 = c(NA, NA, NA, NA, "A")
#' na.to.empty(ex1)
#' na.to.empty(ex2)
#' na.to.empty(ex3)
na.to.empty = function(x){
  x[which(is.na(x))] = ""
  return(x)
}



#' @title Data Frame NA to Empty
#' @description Converts all NA's certain columns of a data.frame to empty values
#' @param x A data.frame
#' @param coltypes Character vector with the types of columns to affect.  Default is "all", which includes logical, integer, double, complex, character, raw, and factor.
#' @return A data.frame with the same dimensions and names as \code{x}.  Columns whose types were specified in coltypes will be converted to character (except factors, which stay factor).
#' @examples
#' V1 = c(LETTERS[1:8], NA, NA)
#' V2 = c(NA, 1:8, NA)
#' V3 = factor(c(rep(c("A","B"), times = 4),NA, NA))
#' ex1 = data.frame(V1 = V1, V2 = V2, V3 = V3, stringsAsFactors = F)
#' DFna.to.empty(ex1)
#' DFna.to.empty(ex1, coltypes = "character")
#' DFna.to.empty(ex1, coltypes = c("character", "factor"))
#' DFna.to.empty(ex1, coltypes = c("character", "integer"))
DFna.to.empty = function(x, coltypes = "all"){
  if(identical(coltypes, "all")) {
    coltypes = c("character", "integer", "logical", "factor", "double", "complex", "raw")
  }
  ColsToUse = unlist(lapply(x,typeof)) %in% coltypes  # determine which columns to use
  factorCols = unlist(lapply(x, is.factor))           # determine which columns are factor
  ColsToUse[factorCols] = ("factor" %in% coltypes)    # set whether to use the factor columns

  for(i in 1:ncol(x)){                  # for each column
    if(ColsToUse[i]){                   # if the column is to be used
      y = unlist(x[,i])                 # get a vector of the current column
      if(is.factor(y)){                 # if y is a factor variable
        yLevels = levels(y)             # grab the levels of y
        if(any(is.na(y))){              # if y has any NA's
          if(!("" %in% yLevels)){       # if y needs a blank level
            levels(y) = c(yLevels, "")  # add a blank level to y
          } # /if y needs a blank level
          y[which(is.na(y))] = ""       # make NA's blank
        } # /if y has any NA's
      } else {                          # if it's not factor
        if(any(is.na(y))){              # if there are any missing values
          y = as.character(y)           # convert to character
          y = na.to.empty(y)            # run na.to.empty
        } # /if y has NA entries
      } # /if-else y is factor
      x[,i] = y                         # load the values back in the data.frame
    } # /if this is a column to use
  } # /for each column
  return(x)                             # return the data.frame
} # /function