R: Convert the case of character objects

char_tolower {quanteda} | R Documentation

## 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)

[Package quanteda version 3.1.0 Index]