stri_subset: Select Elements that Match a Given Pattern¶
Description¶
These functions return or modify a sub-vector where there is a match a given pattern. In other words, they are roughly equivalent (but faster and easier to use) to a call to str[stri_detect(str, ...)]
or str[stri_detect(str, ...)] <- value
.
Usage¶
stri_subset(str, ..., regex, fixed, coll, charclass)
stri_subset(str, ..., regex, fixed, coll, charclass) <- value
stri_subset_fixed(
str,
pattern,
omit_na = FALSE,
negate = FALSE,
...,
opts_fixed = NULL
)
stri_subset_fixed(str, pattern, negate=FALSE, ..., opts_fixed=NULL) <- value
stri_subset_charclass(str, pattern, omit_na = FALSE, negate = FALSE)
stri_subset_charclass(str, pattern, negate=FALSE) <- value
stri_subset_coll(
str,
pattern,
omit_na = FALSE,
negate = FALSE,
...,
opts_collator = NULL
)
stri_subset_coll(str, pattern, negate=FALSE, ..., opts_collator=NULL) <- value
stri_subset_regex(
str,
pattern,
omit_na = FALSE,
negate = FALSE,
...,
opts_regex = NULL
)
stri_subset_regex(str, pattern, negate=FALSE, ..., opts_regex=NULL) <- value
Arguments¶
|
character vector; strings to search in |
|
supplementary arguments passed to the underlying functions, including additional settings for |
|
character vector to be substituted with; replacement function only |
|
character vector; search patterns; for more details refer to stringi-search; the replacement functions accept only one pattern at a time |
|
single logical value; should missing values be excluded from the result? |
|
single logical value; whether a no-match is rather of interest |
|
a named list used to tune up the search engine’s settings; see stri_opts_collator, stri_opts_fixed, and stri_opts_regex, respectively; |
Details¶
Vectorized over str
, and pattern
or value
(replacement version) (with recycling of the elements in the shorter vector if necessary).
stri_subset
and stri_subset<-
are convenience functions. They call either stri_subset_regex
, stri_subset_fixed
, stri_subset_coll
, or stri_subset_charclass
, depending on the argument used.
Value¶
The stri_subset
functions return a character vector. As usual, the output encoding is always UTF-8.
The stri_subset<-
function modifies the str
object ‘in-place’.
See Also¶
Other search_subset: about_search
Examples¶
stri_subset_regex(c('stringi R', '123', 'ID456', ''), '^[0-9]+$')
x <- c('stringi R', '123', 'ID456', '')
stri_subset_regex(x, '[^0-9]+|^$') <- NA
print(x)
x <- c('stringi R', '123', 'ID456', '')
stri_subset_regex(x, '^[0-9]+$', negate=TRUE) <- NA
print(x)