quanteda: char_tolower – R documentation

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char_tolower

Convert the case of character objects

Description

char_tolower and char_toupper are replacements for base::tolower() and base::tolower() based on the stringi package. The stringi functions for case conversion are superior to the base functions because they correctly handle case conversion for Unicode. In addition, the *_tolower() functions provide an option for preserving acronyms.

Usage

char_tolower(x, keep_acronyms = FALSE)

char_toupper(x)

Arguments

`x`	the input object whose character/tokens/feature elements will be case-converted
`keep_acronyms`	logical; if `TRUE`, do not lowercase any all-uppercase words (applies only to `*_tolower()` functions)

Examples

txt1 <- c(txt1 = "b A A", txt2 = "C C a b B")
char_tolower(txt1)
char_toupper(txt1)

# with acronym preservation
txt2 <- c(text1 = "England and France are members of NATO and UNESCO",
          text2 = "NASA sent a rocket into space.")
char_tolower(txt2)
char_tolower(txt2, keep_acronyms = TRUE)
char_toupper(txt2)

quanteda

Quantitative Analysis of Textual Data

v3.0.0

GPL-3

Authors

Kenneth Benoit [cre, aut, cph] (<https://orcid.org/0000-0002-0797-564X>), Kohei Watanabe [aut] (<https://orcid.org/0000-0001-6519-5265>), Haiyan Wang [aut] (<https://orcid.org/0000-0003-4992-4311>), Paul Nulty [aut] (<https://orcid.org/0000-0002-7214-4666>), Adam Obeng [aut] (<https://orcid.org/0000-0002-2906-4775>), Stefan Müller [aut] (<https://orcid.org/0000-0002-6315-4125>), Akitaka Matsuo [aut] (<https://orcid.org/0000-0002-3323-6330>), William Lowe [aut] (<https://orcid.org/0000-0002-1549-6163>), Christian Müller [ctb], European Research Council [fnd] (ERC-2011-StG 283794-QUANTESS)

Initial release