# index0: Zero-based Indexing in
R

The R programming language uses indices that start from 1, but
sometimes it might be handy to be able to index from zero, as is more
typical in mathematical notation and some other programming languages
like C and Python.

## Installation

Install the development version of **index0** from
GitHub with:

```
# install.packages("remotes")
remotes::install_github("Selbosh/index0")
```

## Usage

This R package **index0** provides the
`index0`

class. Subsetting and operations using
`[`

will index from zero rather than one. To return to normal
behaviour, use `as.index1`

or just remove the
`index0`

class from your object.

```
library(index0)
letters0 <- as.index0(letters)
numbers0 <- as.index0(c(2, 3, 4, 5, 6))
```

What is the zeroth letter of the alphabet? What is the zeroth number
in our set?

```
letters0[0]
#> [1] "a"
#> indexed from 0
numbers0[0]
#> [1] 2
#> indexed from 0
```

What are the first, second and fourth letters?

```
letters0[c(1, 2, 4)]
#> [1] "b" "c" "e"
#> indexed from 0
```

Replace the first and third numbers with `NA`

:

```
numbers0[c(1, 3)] <- NA
numbers0
#> [1] 2 NA 4 NA 6
#> indexed from 0
```