R: Divide a vector-like object into groups

split-methods {S4Vectors}

R Documentation

Divide a vector-like object into groups

Description

split divides the data in a vector-like object x into the groups defined by f.

NOTE: This man page is for the split methods defined in the S4Vectors package. See ?base::split for the default method (defined in the base package).

Usage

## S4 method for signature 'Vector,ANY'
split(x, f, drop=FALSE)

## S4 method for signature 'ANY,Vector'
split(x, f, drop=FALSE)

## S4 method for signature 'Vector,Vector'
split(x, f, drop=FALSE)

## S4 method for signature 'list,Vector'
split(x, f, drop=FALSE, ...)

Arguments

`x, f`	2 vector-like objects of the same length. `f` will typically be a factor, but not necessarily.
`drop`	Logical indicating if levels that do not occur should be dropped (if `f` is a factor).
`...`	Arguments passed to `base::split` (see Details below).

Details

The first 3 methods just delegate to the IRanges::splitAsList function defined in the IRanges package.

The method for list does:

    split(x, as.vector(f), drop=drop, ...)

Value

All these methods behave like base::split except that the first 3 methods return a List object instead of an ordinary list.

Examples

## On an Rle object:
x <- Rle(101:105, 6:2)
split(x, c("B", "B", "A", "B", "A"))

## On a DataFrame object:
groups <- c("group1", "group2")
DF <- DataFrame(
    a=letters[1:10],
    i=101:110,
    group=rep(factor(groups, levels=groups), c(3, 7))
)
split(DF, DF$group)

[Package S4Vectors version 0.16.0 Index]