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, ...)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.
# ensure columns "y" and "z" exist
tibble::tibble(x=1:3) %>%
introduce(y="a", z=paste0(y, dplyr::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::tibble(x=1:3, y=c("c", "d", "e")) %>%
introduce(y="a", z=paste0(y, dplyr::row_number()))
#> # A tibble: 3 × 3
#> x y z
#> <int> <chr> <chr>
#> 1 1 c c1
#> 2 2 d d2
#> 3 3 e e3