Use NA of different classes in your project

R has several built-in NA values that correspond to the atomic data types, such as NA (logical), NA_integer_ and NA_character_. Calling use_na() allows the programmer to have NA values of any class. In addition, use_na() provides several useful NA values such as NA_list_, NA_Date_ and NA_POSIXct_.

use_na(path = "R", export = TRUE)

Arguments

path	(character) A path pointing at where to copy the file.
export	If TRUE, the file content is exported to NAMESPACE.

Value

No return value, called for side effects.

Details

The function copies a file with several NA values to 'path/utils-na.R'.

Examples

path <- tempfile()
use_na(path)
print(readLines(file.path(path, "utils-na.R")))
#>  [1] "#' @title Various 'Not Available' / Missing Values"                                            
#>  [2] "#' @description R comes with several built-in NA constants, including `NA`"                    
#>  [3] "#'   (logical), `NA_integer_`, `NA_real_`, `NA_complex_` and `NA_character_`."                 
#>  [4] "#'   Similarly, we can define NA values that are associated with other classes,"               
#>  [5] "#'   such as, `NA_Date_` and `NA_list_`."                                                      
#>  [6] "#' @name na_utiles"                                                                            
#>  [7] "#' @return Predefined constant."                                                               
#>  [8] "NULL"                                                                                          
#>  [9] ""                                                                                              
#> [10] ""                                                                                              
#> [11] "# Atoms -------------------------------------------------------------------"                   
#> [12] "#' @rdname na_utiles"                                                                          
#> [13] "#' @export"                                                                                    
#> [14] "NA_numeric_ <- structure(NA_real_, class = c(\"integer\", \"numeric\"))"                       
#> [15] ""                                                                                              
#> [16] ""                                                                                              
#> [17] "# Timedate ----------------------------------------------------------------"                   
#> [18] "#' @rdname na_utiles"                                                                          
#> [19] "#' @export"                                                                                    
#> [20] "NA_Date_ <- structure(NA_real_, class = \"Date\")"                                             
#> [21] "#' @rdname na_utiles"                                                                          
#> [22] "#' @export"                                                                                    
#> [23] "NA_POSIXct_ <- structure(.POSIXct(NA_real_, tz = \"UTC\"), class = c(\"POSIXct\", \"POSIXt\"))"
#> [24] ""                                                                                              
#> [25] ""                                                                                              
#> [26] "# Arrays ------------------------------------------------------------------"                   
#> [27] "#' @rdname na_utiles"                                                                          
#> [28] "#' @export"                                                                                    
#> [29] "NA_list_ <- structure(list(), class = \"list\")"                                               
#> [30] "#' @rdname na_utiles"                                                                          
#> [31] "#' @export"                                                                                    
#> [32] "NA_data.frame_ <- structure(data.frame(), class = \"data.frame\")"