# enum: Enumeration-type Representation of Vectors In inum: Interval and Enum-Type Representation of Vectors

## Description

Elements of a vector are stored as a set of levels and an integer representing the enumeration.

## Usage

 `1` ``` enum(x) ```

## Arguments

 `x` A vector. Currently, methods for factors, logicals, integers, and numeric vectors are implemented.

## Details

The unique elements of `x` are stored as a `levels` attribute to an integer representing the enumeration. `levels` and `nlevels` methods are available. This is essentially the same as `factor` where the levels can be arbitrary vectors, not just characters.

## Value

An object of class `enum`. A value of `0` encodes `NA`.

`factor`

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14``` ```(ex <- enum(x <- gl(2, 2))) all.equal(levels(ex)[ex], x) (ex <- enum(x <- rep(c(TRUE, FALSE), 2))) all.equal(levels(ex)[ex], x) (ex <- enum(x <- rep(1:5, 2))) all.equal(levels(ex)[ex], x) (ex <- enum(x <- rep(1:5 + .5, 2))) all.equal(levels(ex)[ex], x) (ex <- enum(x <- c(NA, rep(1:5 + .5, 2)))) all.equal(c(NA, levels(ex))[unclass(ex) + 1L], x) ```

inum documentation built on Dec. 13, 2017, 1:03 a.m.