fjoin_cross: Cross join

In fjoin: Data Frame Joins Leveraging 'data.table'

Cross join

Description

Cross join of x and y

Usage

fjoin_cross(
  x = NULL,
  y = NULL,
  order = "left",
  select = NULL,
  select.x = NULL,
  select.y = NULL,
  prefix.y = "R.",
  do = !(is.null(x) && is.null(y)),
  show = !do
)

Arguments

x, y	data.frame-like objects (plain, data.table, tibble, sf, list, etc.) or else both omitted for a mock join statement with no data. See Details.
order	Whether the row order of the result should reflect x then y ("left") or y then x ("right"). Default "left".
select, select.x, select.y	Character vectors of columns to be selected from either input if present (select) or specifically from one or other of them (e.g. select.x). NULL (the default) selects all columns. Use "" or NA to select no columns. Join columns are always selected. See Details.
prefix.y	A prefix to attach to column names in y that are the same as a column name in x. Default "R.".
do	Whether to execute the join. If FALSE, show is set to TRUE and the data.table code for the join is printed to the console instead. Default is TRUE unless x and y are both omitted/NULL, in which case a mock join statement is produced. See Details.
show	Whether to print the data.table code for the join to the console. Default is the opposite of do. If x and y are both omitted/NULL, mock join code is displayed.

Details

Details are as for e.g. fjoin_inner except for remarks about join columns and matching logic, which do not apply.

Value

A data.frame, data.table, (grouped) tibble, sf, or sf-tibble, or else NULL if do is FALSE. See Details.

See Also

See the package-level documentation fjoin for related functions.

Examples

# data frames
df1 <- data.table::fread(data.table = FALSE, input = "
bread    kcal
Brown     150
White     180
Baguette  250
")

df2 <- data.table::fread(data.table = FALSE, input = "
filling kcal
Cheese   200
Pâté     160
")

fjoin_cross(df1, df2)
fjoin_cross(df1, df2, order = "right")

fjoin documentation built on Dec. 11, 2025, 5:07 p.m.