R/casechange-functions.R
dfm_tolower.Rddfm_tolower() and dfm_toupper() convert the features of the dfm or
fcm to lower and upper case, respectively, and then recombine the counts.
dfm_tolower(x, keep_acronyms = FALSE)
dfm_toupper(x)
fcm_tolower(x, keep_acronyms = FALSE)
fcm_toupper(x)the input object whose character/tokens/feature elements will be case-converted
logical; if TRUE, do not lowercase any
all-uppercase words (applies only to *_tolower() functions)
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".
# for a document-feature matrix
dfmat <- dfm(tokens(c("b A A", "C C a b B")), tolower = FALSE)
dfmat
#> Document-feature matrix of: 2 documents, 5 features (40.00% sparse) and 0 docvars.
#> features
#> docs b A C a B
#> text1 1 2 0 0 0
#> text2 1 0 2 1 1
dfm_tolower(dfmat)
#> Document-feature matrix of: 2 documents, 3 features (16.67% sparse) and 0 docvars.
#> features
#> docs b a c
#> text1 1 2 0
#> text2 2 1 2
dfm_toupper(dfmat)
#> Document-feature matrix of: 2 documents, 3 features (16.67% sparse) and 0 docvars.
#> features
#> docs B A C
#> text1 1 2 0
#> text2 2 1 2
# for a feature co-occurrence matrix
fcmat <- fcm(tokens(c("b A A d", "C C a b B e")),
context = "document")
fcmat
#> Feature co-occurrence matrix of: 7 by 7 features.
#> features
#> features b A d C a B e
#> b 0 2 1 2 1 1 1
#> A 0 1 2 0 0 0 0
#> d 0 0 0 0 0 0 0
#> C 0 0 0 1 2 2 2
#> a 0 0 0 0 0 1 1
#> B 0 0 0 0 0 0 1
#> e 0 0 0 0 0 0 0
fcm_tolower(fcmat)
#> Feature co-occurrence matrix of: 5 by 5 features.
#> features
#> features b a d c e
#> b 1 3 1 2 2
#> a 1 1 2 0 1
#> d 0 0 0 0 0
#> c 2 2 0 1 2
#> e 0 0 0 0 0
fcm_toupper(fcmat)
#> Feature co-occurrence matrix of: 5 by 5 features.
#> features
#> features B A D C E
#> B 1 3 1 2 2
#> A 1 1 2 0 1
#> D 0 0 0 0 0
#> C 2 2 0 1 2
#> E 0 0 0 0 0