Works like dplyr::mutate() but without changing existing columns, but only adding new ones. Useful to add possibly missing columns with default values.

introduce(.data, ...)

Arguments

.data

A data frame, data frame extension (e.g. a tibble), or a lazy data frame (e.g. from dbplyr or dtplyr). See Methods, below, for more details.

...

<data-masking> Name-value pairs. The name gives the name of the column in the output.

The value can be:

  • A vector of length 1, which will be recycled to the correct length.

  • A vector the same length as the current group (or the whole data frame if ungrouped).

  • NULL, to remove the column.

  • A data frame or tibble, to create multiple columns in the output.

Examples

# ensure columns "y" and "z" exist
tibble(x=1:3) %>%
 introduce(y="a", z=paste0(y, row_number()))
#> # A tibble: 3 × 3
#>       x y     z    
#>   <int> <chr> <chr>
#> 1     1 a     a1   
#> 2     2 a     a2   
#> 3     3 a     a3   
# ensure columns "y" and "z" exist, but do not overwrite "y"
tibble(x=1:3, y=c("c", "d", "e")) %>%
 introduce(y="a", z=paste0(y, row_number()))
#> # A tibble: 3 × 3
#>       x y     z    
#>   <int> <chr> <chr>
#> 1     1 c     c1   
#> 2     2 d     d2   
#> 3     3 e     e3