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photobiology (version 0.9.20)

head_tail: Return the First and Last Part of an Object

Description

Returns the first and last "parts" (rows or members) of a spectrum, dataframe, vector, function, table or ftable. In other words, the combined output from methods head and tail.

Usage

head_tail(x, ...)

# S3 method for default head_tail(x, n = 3L, ...)

# S3 method for data.frame head_tail(x, n = 3L, ...)

# S3 method for matrix head_tail(x, n = 3L, ...)

# S3 method for function head_tail(x, n = 6L, ...)

# S3 method for table head_tail(x, n = 6L, ...)

# S3 method for ftable head_tail(x, n = 6L, ...)

Arguments

x

an R object.

...

arguments to be passed to or from other methods.

n

a single integer. If positive, half the 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, to be retained from each end. If negative, all but the n last and n first number of elements of x.

Value

An object (usually) like x but generally smaller. For ftable objects x, a transformed format(x).

Methods (by class)

  • default:

  • data.frame:

  • matrix:

  • function:

  • table:

  • ftable:

Details

The value returned by head_tail() is equivalent to row binding the the values returned by head() and tail(), although not implemented in this way. The same specializations as defined in package 'utils' for head() and tail() have been implemented.

See Also

head, and compare the examples and the values returned to the examples below.

Examples

Run this code
# NOT RUN {
head_tail(letters)
head_tail(letters, n = -6L)
head_tail(freeny.x, n = 10L)
head_tail(freeny.y)

head_tail(stats::ftable(Titanic))

# }

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