Add an Enumeration Column

Prepends (or inserts) a column of enumeration labels – lowercase or uppercase Roman numerals, or Arabic numbers.

Usage

appendEnum(
  x,
  type = c("roman-lcase", "roman-ucase", "arabic"),
  suffix = ". ",
  startWith = 1L,
  after = 0L,
  colName = NULL
)

Arguments

x

a data.frame or matrix (vectors are coerced via matrix()).

type

enumeration style: "roman-lcase", "roman-ucase" or "arabic".

suffix

text appended to each enumeration label.

startWith

first enumeration index.

after

position after which the column is inserted (see appendX()); default 0L prepends it.

colName

optional name for the new column; NULL (default) leaves it unnamed for matrices, while for data frames a default name ("V1") is used.

Value

x with an additional enumeration column.

See also

append()

Other data.append: appendRowNames(), appendX(), multMerge()

Examples

d <- data.frame(x = 1:3, y = c("a", "b", "c"))
appendEnum(d)
#>      V1 x y
#> 1   i.  1 a
#> 2  ii.  2 b
#> 3 iii.  3 c

appendEnum(d, type = "arabic", suffix = ") ")
#>    V1 x y
#> 1 1)  1 a
#> 2 2)  2 b
#> 3 3)  3 c

# insert after the first column instead of prepending
appendEnum(d, after = 1L, colName = "no")
#>   x    no y
#> 1 1   i.  a
#> 2 2  ii.  b
#> 3 3 iii.  c