stri_duplicated: Determine Duplicated Elements

Description Usage Arguments Details Value References See Also Examples

View source: R/sort.R

Description

stri_duplicated() determines which strings in a character vector are duplicates of other elements.

stri_duplicated_any() determines if there are any duplicated strings in a character vector.

Usage

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stri_duplicated(
  str,
  from_last = FALSE,
  fromLast = from_last,
  ...,
  opts_collator = NULL
)

stri_duplicated_any(
  str,
  from_last = FALSE,
  fromLast = from_last,
  ...,
  opts_collator = NULL
)

Arguments

str

a character vector

from_last

a single logical value; indicates whether search should be performed from the last to the first string

fromLast

[DEPRECATED] alias of from_last

...

additional settings for opts_collator

opts_collator

a named list with ICU Collator's options, see stri_opts_collator, NULL for default collation options

Details

Missing values are regarded as equal.

Unlike duplicated and anyDuplicated, these functions test for canonical equivalence of strings (and not whether the strings are just bytewise equal) Such operations are locale-dependent. Hence, stri_duplicated and stri_duplicated_any are significantly slower (but much better suited for natural language processing) than their base R counterparts.

See also stri_unique for extracting unique elements.

Value

stri_duplicated() returns a logical vector of the same length as str. Each of its elements indicates whether a canonically equivalent string was already found in str.

stri_duplicated_any() returns a single non-negative integer. Value of 0 indicates that all the elements in str are unique. Otherwise, it gives the index of the first non-unique element.

References

Collation - ICU User Guide, http://userguide.icu-project.org/collation

See Also

Other locale_sensitive: %s<%(), about_locale, about_search_boundaries, about_search_coll, stri_compare(), stri_count_boundaries(), stri_enc_detect2(), stri_extract_all_boundaries(), stri_locate_all_boundaries(), stri_opts_collator(), stri_order(), stri_sort_key(), stri_sort(), stri_split_boundaries(), stri_trans_tolower(), stri_unique(), stri_wrap()

Examples

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# In the following examples, we have 3 duplicated values,
# 'a' - 2 times, NA - 1 time
stri_duplicated(c('a', 'b', 'a', NA, 'a', NA))
stri_duplicated(c('a', 'b', 'a', NA, 'a', NA), from_last=TRUE)
stri_duplicated_any(c('a', 'b', 'a', NA, 'a', NA))

# compare the results:
stri_duplicated(c('\u0105', stri_trans_nfkd('\u0105')))
duplicated(c('\u0105', stri_trans_nfkd('\u0105')))

stri_duplicated(c('gro\u00df', 'GROSS', 'Gro\u00df', 'Gross'), strength=1)
duplicated(c('gro\u00df', 'GROSS', 'Gro\u00df', 'Gross'))

stringi documentation built on Sept. 13, 2020, 5:17 p.m.