head {utils}R Documentation

Return the First or Last Part of an Object

Description

Returns the first or last parts of a vector, matrix, data frame or function.

Usage

head(x, ...)
## Default S3 method:
head(x, n = 6, ...)
## S3 method for class 'data.frame':
head(x, n = 6, ...)
## S3 method for class 'matrix':
head(x, n = 6, ...)

tail(x, ...)
## Default S3 method:
tail(x, n = 6, ...)
## S3 method for class 'data.frame':
tail(x, n = 6, ...)
## S3 method for class 'matrix':
tail(x, n = 6, addrownums = TRUE, ...)

Arguments

x an object
n size for the resulting object: number of elements for a vector (including lists), rows for a matrix or data frame or lines for a function.
addrownums if there are no row names, create them from the row numbers.
... arguments to be passed to or from other methods.

Details

For matrices and data frames, the first/last n rows are returned. For functions, the first/last n lines of the deparsed function are returned as character strings.

If a matrix has no row names, then tail() will add row names of the form "[n,]" to the result, so that it looks similar to the last lines of x when printed. Setting addrownums = FALSE suppresses this behaviour.

Value

An object (usually) like x but generally smaller.

Author(s)

Patrick Burns, improved and corrected by R-Core

Examples

head(freeny.x, n = 10)
head(freeny.y)

tail(freeny.x)
tail(freeny.y)

tail(library)

[Package utils version 2.1.0 Index]