brackets {mclm} | R Documentation |
Subset an object by different criteria
Description
This method can be used to subset objects based on different criteria.
Usage
## S3 method for class 'fnames'
x[i, invert = FALSE, ...]
## S3 replacement method for class 'fnames'
x[i, invert = FALSE] <- value
## S3 method for class 'freqlist'
x[i, invert = FALSE, ...]
## S3 method for class 'tokens'
x[i, invert = FALSE, ...]
## S3 replacement method for class 'tokens'
x[i, invert = FALSE, ...] <- value
## S3 method for class 'types'
x[i, invert = FALSE, ...]
## S3 replacement method for class 'types'
x[i, invert = FALSE] <- value
Arguments
x |
An object of any of the classes for which the method is implemented. |
i |
Selection criterion; depending on its class, it behaves differently. |
invert |
Logical. Whether the matches should be selected rather than the non-matches. |
... |
Additional arguments. |
value |
Value to assign. |
Details
The subsetting method with the notation []
, applied to mclm objects,
is part of a family of subsetting methods: see keep_pos()
, keep_re()
,
keep_types()
and keep_bool()
. In this case, the argument i
is the selection
criterion and, depending on its class, the method behaves different:
providing a numeric vector is equivalent to calling
keep_pos()
,providing a logical vector is equivalent to calling
keep_bool()
,providing a
types
object or a character vector is equivalent to callingkeep_types()
.
When the notation x[i, ...]
is used, it is also possible to set the invert
argument to TRUE
(which then is one of the additional arguments in ...
).
This invert
argument then serves the same purpose as the invert
argument
in the keep_
methods, turning it into a drop_
method.
Value
Object of the same class as x
with the selected elements only.
See Also
Other subsetters:
keep_bool()
,
keep_pos()
,
keep_re()
,
keep_types()
Examples
# For a 'freqlist' object --------------------
(flist <- freqlist("The man and the mouse.", as_text = TRUE))
## like keep_re()
flist[re("[ao]")]
flist[re("[ao]"), invert = TRUE]
## like keep_pos()
flist[type_freqs(flist) < 2]
flist[ranks(flist) <= 3]
flist[ranks(flist) <= 3, invert = TRUE]
flist[2:3]
## like keep_bool()
(flist2 <- keep_bool(flist, type_freqs(flist) < 2))
flist2[orig_ranks(flist2) > 2]
## like keep_types()
flist[c("man", "and")]
flist[as_types(c("man", "and"))]
# For a 'types' object -----------------------
(tps <- as_types(letters[1:10]))
tps[c(1, 3, 5, 7, 9)]
tps[c(TRUE, FALSE)]
tps[c("a", "c", "e", "g", "i")]
tps[c(1, 3, 5, 7, 9), invert = TRUE]
tps[c(TRUE, FALSE), invert = TRUE]
tps[c("a", "c", "e", "g", "i"), invert = TRUE]
# For a 'tokens' object ----------------------
(tks <- as_tokens(letters[1:10]))
tks[re("[acegi]"), invert = TRUE]
tks[c(1, 3, 5, 7, 9), invert = TRUE]
tks[c(TRUE, FALSE), invert = TRUE]
tks[c("a", "c", "e", "g", "i"), invert = TRUE]