order: Ordering permutation

In Bioconductor/BiocGenerics: S4 generic functions used in Bioconductor

Ordering permutation

Description

order returns a permutation which rearranges its first argument into ascending or descending order, breaking ties by further arguments.

NOTE: This man page is for the order S4 generic function defined in the BiocGenerics package. See ?base::order for the default method (defined in the base package). Bioconductor packages can define specific methods for objects (typically vector-like) not supported by the default method.

Usage

order(..., na.last=TRUE, decreasing=FALSE, method=c("auto", "shell", "radix"))

Arguments

...	One or more vector-like objects, all of the same length.
na.last, decreasing, method	See ?base::order for a description of these arguments.

Value

The default method (see ?base::order) returns an integer vector of length N where N is the common length of the input objects. This integer vector represents a permutation of N elements and can be used to rearrange the first argument in ... into ascending or descending order (by subsetting it).

Specific methods defined in Bioconductor packages should also return an integer vector representing a permutation of N elements.

Note

TO DEVELOPERS:

Specific order methods should preferably be made "stable" for consistent behavior across platforms and consistency with base::order(). Note that C qsort() is not "stable" so order methods that use qsort() at the C-level need to ultimately break ties by position, which can easily be done by adding a little extra code at the end of the comparison function passed to qsort().

order(x, decreasing=TRUE) is not always equivalent to rev(order(x)).

order, sort, and rank methods for specific vector-like objects should adhere to the same underlying order that should be conceptually defined as a binary relation on the set of all possible vector values. For completeness, this binary relation should also be incarnated by a <= method.

See Also

• base::order for the default order method.

• showMethods for displaying a summary of the methods defined for a given generic function.

• selectMethod for getting the definition of a specific method.

• order,IntegerRanges-method in the IRanges package for an example of a specific order method (defined for IntegerRanges objects).

• BiocGenerics for a summary of all the generics defined in the BiocGenerics package.

Examples

order
showMethods("order")
selectMethod("order", "ANY")  # the default method

Bioconductor/BiocGenerics documentation built on Nov. 17, 2024, 6:52 p.m.