R: Extract Unique Elements

stri_unique {stringi} | R Documentation

## 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

### 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.

### Value

Returns a character vector.

### 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

    # 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)

[Package stringi version 1.2.4 Index]