# numeric_version

##### Numeric Versions

A simple S3 class for representing numeric versions including package versions, and associated methods.

- Keywords
- utilities

##### Usage

```
numeric_version(x, strict = TRUE)
package_version(x, strict = TRUE)
R_system_version(x, strict = TRUE)
getRversion()
```

##### Arguments

- x
- a character vector with suitable numeric version strings (see
‘Details’); for
`package_version`

, alternatively an R version object as obtained by`R.version`

. - strict
- a logical indicating whether invalid numeric versions should results in an error (default) or not.

##### Details

Numeric versions are sequences of one or more non-negative integers, usually (e.g., in package ‘DESCRIPTION’ files) represented as character strings with the elements of the sequence concatenated and separated by single . or - characters. R package versions consist of at least two such integers, an R system version of exactly three (major, minor and patchlevel).

Functions `numeric_version`

, `package_version`

and
`R_system_version`

create a representation from such strings (if
suitable) which allows for coercion and testing, combination,
comparison, summaries (min/max), inclusion in data frames,
subscripting, and printing. The classes can hold a vector of such
representations.

`getRversion`

returns the version of the running R as an R
system version object.

The `[[`

operator extracts or replaces a single version. To
access the integers of a version use two indices: see the examples.

##### See Also

`compareVersion`

;
`packageVersion`

for the version of a specific R package.
`R.version`

etc for the version of R (and the information
underlying `getRversion()`

).

##### Examples

`library(base)`

```
x <- package_version(c("1.2-4", "1.2-3", "2.1"))
x < "1.4-2.3"
c(min(x), max(x))
x[2, 2]
x$major
x$minor
if(getRversion() <= "2.5.0") { ## work around missing feature
cat("Your version of R, ", as.character(getRversion()),
", is outdated.\n",
"Now trying to work around that ...\n", sep = "")
}
x[[c(1, 3)]] # '4' as a numeric vector, same as x[1, 3]
x[1, 3] # 4 as an integer
x[[2, 3]] <- 0 # zero the patchlevel
x[[c(2, 3)]] <- 0 # same
x
x[[3]] <- "2.2.3"; x
x <- c(x, package_version("0.0"))
is.na(x)[4] <- TRUE
stopifnot(identical(is.na(x), c(rep(FALSE,3), TRUE)),
anyNA(x))
```

*Documentation reproduced from package base, version 3.1.3, License: Part of R 3.1.3*