R: Add an "id" Variable to a Dataset

getanID {splitstackshape}

R Documentation

Add an "id" Variable to a Dataset

Description

Many functions will not work properly if there are duplicated ID variables in a dataset. This function is a convenience function for .N from the "data.table" package to create an ".id" variable that when used in conjunction with the existing ID variables, should be unique.

Usage

getanID(data, id.vars = NULL)

Arguments

`data`	The input `data.frame` or `data.table`.
`id.vars`	The variables that should be treated as ID variables. Defaults to `NULL`, at which point all variables are used to create the new ID variable.

Value

The input dataset (as a data.table) if ID variables are unique, or the input dataset with a new column named ".id".

Author(s)

Ananda Mahto

Examples

mydf <- data.frame(IDA = c("a", "a", "a", "b", "b"),
                   IDB = c(1, 1, 1, 1, 1), values = 1:5)
mydf
getanID(mydf, c("IDA", "IDB"))

mydf <- data.frame(IDA = c("a", "a", "a", "b", "b"),
                   IDB = c(1, 2, 1, 1, 2), values = 1:5)
mydf
getanID(mydf, 1:2)

[Package splitstackshape version 1.4.2 Index]