quanteda (version 4.0.1)

dfm_tolower: Convert the case of the features of a dfm and combine

Description

dfm_tolower() and dfm_toupper() convert the features of the dfm or fcm to lower and upper case, respectively, and then recombine the counts.

Usage

dfm_tolower(x, keep_acronyms = FALSE)
dfm_toupper(x)
fcm_tolower(x, keep_acronyms = FALSE)
fcm_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)

Details

fcm_tolower() and fcm_toupper() convert both dimensions of the fcm to lower and upper case, respectively, and then recombine the counts. This works only on fcm objects created with context = "document".

Examples

# for a document-feature matrix
dfmat <- dfm(tokens(c("b A A", "C C a b B")), tolower = FALSE)
dfmat
dfm_tolower(dfmat)
dfm_toupper(dfmat)

# for a feature co-occurrence matrix
fcmat <- fcm(tokens(c("b A A d", "C C a b B e")),
             context = "document")
fcmat
fcm_tolower(fcmat)
fcm_toupper(fcmat)