Add missing columns to a data frame with specified fill values

This function checks a data frame for missing columns specified by the user. If any are missing, it adds these columns to the data frame, filling them with a specified value.

Usage

AddMissingCols(DT, FillVal = NA_character_, ...)

Arguments

DT

A data frame to which missing columns will be added. This parameter cannot be NULL.

FillVal

The value to fill the missing columns with. This parameter defaults to NA_character_, but can be changed to any scalar value as required.

...

Column names as character strings.

Value

a data frame with the missing columns added, if any were missing.

Author

Ahmed El-Gabbas

Examples

mtcars2 <- dplyr::select(mtcars, seq_len(3)) %>%
  head() %>%
  tibble::as_tibble()

mtcars2
#> # A tibble: 6 × 3
#>     mpg   cyl  disp
#>   <dbl> <dbl> <dbl>
#> 1  21       6   160
#> 2  21       6   160
#> 3  22.8     4   108
#> 4  21.4     6   258
#> 5  18.7     8   360
#> 6  18.1     6   225

# -------------------------------------------

mtcars2 %>%
 AddMissingCols(FillVal = NA_character_, A, B, C) %>%
 AddMissingCols(FillVal = as.integer(10), D)
#> # A tibble: 6 × 7
#>     mpg   cyl  disp A     B     C         D
#>   <dbl> <dbl> <dbl> <chr> <chr> <chr> <int>
#> 1  21       6   160 NA    NA    NA       10
#> 2  21       6   160 NA    NA    NA       10
#> 3  22.8     4   108 NA    NA    NA       10
#> 4  21.4     6   258 NA    NA    NA       10
#> 5  18.7     8   360 NA    NA    NA       10
#> 6  18.1     6   225 NA    NA    NA       10

# -------------------------------------------

AddCols <- c("Add1", "Add2")
mtcars2 %>%
 AddMissingCols(FillVal = NA_real_, AddCols)
#> # A tibble: 6 × 5
#>     mpg   cyl  disp  Add1  Add2
#>   <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1  21       6   160    NA    NA
#> 2  21       6   160    NA    NA
#> 3  22.8     4   108    NA    NA
#> 4  21.4     6   258    NA    NA
#> 5  18.7     8   360    NA    NA
#> 6  18.1     6   225    NA    NA