Learn R Programming

stringi (version 1.2.2)

stri_unique: Extract Unique Elements

Description

This function returns a character vector like str, but with duplicate elements removed.

Usage

stri_unique(str, ..., opts_collator = NULL)

Arguments

str

a character vector

...

additional settings for opts_collator

opts_collator

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

Value

Returns a character vector.

Details

As usual in stringi, no attributes are copied. Unlike unique, this function tests for canonical equivalence of strings (and not whether the strings are just bytewise equal). Such an operation is locale-dependent. Hence, stri_unique is significantly slower (but much better suited for natural language processing) than its base R counterpart.

See also stri_duplicated for indicating non-unique elements.

References

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

See Also

Other locale_sensitive: %s<%, stri_compare, stri_count_boundaries, stri_duplicated, stri_enc_detect2, stri_extract_all_boundaries, stri_locate_all_boundaries, stri_opts_collator, stri_order, stri_split_boundaries, stri_trans_tolower, stri_wrap, stringi-locale, stringi-search-boundaries, stringi-search-coll

Examples

Run this code
# NOT RUN {
# normalized and non-Unicode-normalized version of the same code point:
stri_unique(c("\u0105", stri_trans_nfkd("\u0105")))
unique(c("\u0105", stri_trans_nfkd("\u0105")))

stri_unique(c("gro\u00df", "GROSS", "Gro\u00df", "Gross"), strength=1)

# }

Run the code above in your browser using DataLab