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

to_integer {fixest}

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.join = 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.join`	Logical, or character, scalar, defaults to `FALSE`. Only used if multiple vectors are to be transformed into integers. If `multi.join` is not `FALSE`, then the values of the different vectors will be collated using `paste` with `collapse=multi.join`.

Details

If multiple vectors have to be combined and add_items=TRUE, to have user readable values in the items, you should add the argument multi.join so that the values of the vectors are combined in a "user-readable" way. Note that in the latter case, the algorithm is much much slower.

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.

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
#

# by default, the two vector are fast combined, and items are meaningless
to_integer(x1, x2, add_items = TRUE)

# You can use multi.join to have human-readable values for the items:
to_integer(x1, x2, add_items = TRUE, multi.join = TRUE)

to_integer(x1, x2, add_items = TRUE, multi.join = "; ")

[Package fixest version 0.8.4 Index]