keep_bool: Subset an object based on logical criteria

In mclm: Mastering Corpus Linguistics Methods

Subset an object based on logical criteria

Description

These methods can be used to subset objects based on a logical vector.

Usage

keep_bool(x, bool, invert = FALSE, ...)

drop_bool(x, bool, ...)

## S3 method for class 'fnames'
drop_bool(x, bool, ...)

## S3 method for class 'fnames'
keep_bool(x, bool, invert = FALSE, ...)

## S3 method for class 'freqlist'
drop_bool(x, bool, ...)

## S3 method for class 'freqlist'
keep_bool(x, bool, invert = FALSE, ...)

## S3 method for class 'tokens'
drop_bool(x, bool, ...)

## S3 method for class 'tokens'
keep_bool(x, bool, invert = FALSE, ...)

## S3 method for class 'types'
drop_bool(x, bool, ...)

## S3 method for class 'types'
keep_bool(x, bool, invert = FALSE, ...)

Arguments

x	An object of any of the classes for which the method is implemented.
bool	A logical vector of the same length as x. If bool is not of the correct length, it is recycled. Assuming invert is FALSE, those items are selected for which bool is TRUE.
invert	Logical. Whether the matches should be selected rather than the non-matches.
...	Additional arguments.

Details

The methods keep_pos() and drop_pos() are part of a family of methods of the mclm package used to subset different objects. The methods starting with keep_ extract the items in x based on the criterion specified by the second argument. In contrast, the methods starting with drop_ exclude the items that match the criterion in the same argument.

Calling a drop_ method is equivalent to calling its keep_ counterpart when the invert argument is TRUE.

Value

Object of the same class as x with the selected elements only.

See Also

Other subsetters: brackets, keep_pos(), keep_re(), keep_types()

Examples

# For a 'freqlist' object---------------------
(flist <- freqlist("The man and the mouse.", as_text = TRUE))

keep_bool(flist, type_freqs(flist) < 2)
drop_bool(flist, type_freqs(flist) >= 2)
keep_bool(flist, ranks(flist) <= 3)

keep_bool(flist, c(FALSE, TRUE, TRUE, FALSE)) 

(flist2 <- keep_bool(flist, type_freqs(flist) < 2))
keep_bool(flist2, orig_ranks(flist2) > 2)

# For a 'types' object ----------------------
(tps <- as_types(letters[1:10]))

keep_bool(tps, c(TRUE, FALSE))
drop_bool(tps, c(TRUE, FALSE))

# For a 'tokens' object ----------------------
(tks <- as_tokens(letters[1:10]))

keep_bool(tks, c(TRUE, FALSE))
drop_bool(tks, c(TRUE, FALSE))

mclm documentation built on Oct. 3, 2022, 9:07 a.m.