to_integer: Fast transform of any type of vector(s) into an integer...
In fixest: Fast Fixed-Effects Estimations

to_integer

R Documentation

Fast transform of any type of vector(s) into an integer vector

Description

Tool to transform any type of vector, or even combination of vectors, into an integer vector ranging from 1 to the number of unique values. This actually creates an unique identifier vector.

Usage

to_integer(
  ...,
  sorted = FALSE,
  add_items = FALSE,
  items.list = FALSE,
  multi.df = FALSE,
  multi.join = "_",
  internal = FALSE
)

Arguments

`...`	Vectors of any type, to be transformed in integer.
`sorted`	Logical, default is `FALSE`. Whether the integer vector should make reference to sorted values?
`add_items`	Logical, default is `FALSE`. Whether to add the unique values of the original vector(s). If requested, an attribute `items` is created containing the values (alternatively, they can appear in a list if `items.list=TRUE`).
`items.list`	Logical, default is `FALSE`. Only used if `add_items=TRUE`. If `TRUE`, then a list of length 2 is returned with `x` the integer vector and `items` the vector of items.
`multi.df`	Logical, default is `FALSE`. If `TRUE` then a data.frame listing the unique elements is returned in the form of a data.frame. Ignored if `add_items = FALSE`.
`multi.join`	Character scalar used to join the items of multiple vectors. The default is `"_"`. Ignored if `add_items = FALSE`.
`internal`	Logical, default is `FALSE`. For programming only. If this function is used within another function, setting `internal = TRUE` is needed to make the evaluation of `...` valid. End users of `to_integer` should not care.

Value

Reruns a vector of the same length as the input vectors. If add_items=TRUE and items.list=TRUE, a list of two elements is returned: x being the integer vector and items being the unique values to which the values in x make reference.

Author(s)

Laurent Berge

Examples


x1 = iris$Species
x2 = as.integer(iris$Sepal.Length)

# transforms the species vector into integers
to_integer(x1)

# To obtain the "items":
to_integer(x1, add_items = TRUE)
# same but in list form
to_integer(x1, add_items = TRUE, items.list = TRUE)

# transforms x2 into an integer vector from 1 to 4
to_integer(x2, add_items = TRUE)

# To have the sorted items:
to_integer(x2, add_items = TRUE, sorted = TRUE)

# The result can safely be used as an index
res = to_integer(x2, add_items = TRUE, sorted = TRUE, items.list = TRUE)
all(res$items[res$x] == x2)


#
# Multiple vectors
#

to_integer(x1, x2, add_items = TRUE)

# You can use multi.join to handle the join of the items:
to_integer(x1, x2, add_items = TRUE, multi.join = "; ")

fixest documentation built on Nov. 24, 2023, 5:11 p.m.