fctr {data.table}R Documentation

Create a factor retaining original ordering

Description

Creates a factor.

By default, the output will have its levels in the original order, i.e., levels = unique(x), as opposed to factor's default where levels = sort(unique(x)).

Usage

fctr(x, levels=unique(x), ..., sort=FALSE, rev=FALSE)

Arguments

x

Object to be turned into a factor.

levels

Levels for the new factor; unique(x) by default.

...

Other arguments passed to factor.

sort

Logical, default FALSE. Should levels be sorted?

rev

Logical, default FALSE. Should levels be reversed? Applied after sort.

Value

Factor vector having levels ordered according to the order of elements in input and arguments sort, rev.

Examples

levels(factor(c("b","a","c")))
levels(fctr(c("b","a","c")))
levels(fctr(c("b","a","c"), rev=TRUE))
levels(fctr(c("b","a","c"), sort=TRUE))
levels(fctr(c("b","a","c"), sort=TRUE, rev=TRUE))
[Package data.table version 1.17.99 Index]