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Factors

Source: R/integer64.R
factor.Rd

The function factor is used to encode a vector as a factor.

Usage

factor(
  x = character(),
  levels,
  labels = levels,
  exclude = NA,
  ordered = is.ordered(x),
  nmax = NA
)

ordered(x = character(), ...)

Arguments

x

a vector of data, usually taking a small number of distinct values.

levels

an optional vector of the unique values (as character strings) that x might have taken. The default is the unique set of values taken by as.character(x), sorted into increasing order of x. Note that this set can be specified as smaller than sort(unique(x)).

labels

either an optional character vector of labels for the levels (in the same order as levels after removing those in exclude), or a character string of length 1. Duplicated values in labels can be used to map different values of x to the same factor level.

exclude

a vector of values to be excluded when forming the set of levels. This may be factor with the same level set as x or should be a character.

ordered

logical flag to determine if the levels should be regarded as ordered (in the order given).

nmax

an upper bound on the number of levels.

...

(in ordered(.)): any of the above, apart from ordered itself.

Value

An object of class "factor" or "ordered".

See also

factor

Examples

  x <- as.integer64(c(132724613L, -2143220989L, -1L, NA, 1L))
  factor(x)
#> [1] 132724613   -2143220989 -1          <NA>        1          
#> Levels: -2143220989 -1 1 132724613
  ordered(x)
#> [1] 132724613   -2143220989 -1          <NA>        1          
#> Levels: -2143220989 < -1 < 1 < 132724613