These functions convert between the various valid formats for corpus and tokens objects. By using these in other packages, maintainers need to only handle whichever specific format they would like to work with, but gain the freedom to output (or convert into) the one most suited to their package's paradigm.
Usage
tif_as_corpus_character(corpus)
# Default S3 method
tif_as_corpus_character(corpus)
# S3 method for class 'character'
tif_as_corpus_character(corpus)
# S3 method for class 'data.frame'
tif_as_corpus_character(corpus)
tif_as_corpus_df(corpus)
# Default S3 method
tif_as_corpus_df(corpus)
# S3 method for class 'character'
tif_as_corpus_df(corpus)
# S3 method for class 'data.frame'
tif_as_corpus_df(corpus)
tif_as_tokens_df(tokens)
# Default S3 method
tif_as_tokens_df(tokens)
# S3 method for class 'list'
tif_as_tokens_df(tokens)
# S3 method for class 'data.frame'
tif_as_tokens_df(tokens)
tif_as_tokens_list(tokens)
# Default S3 method
tif_as_tokens_list(tokens)
# S3 method for class 'list'
tif_as_tokens_list(tokens)
# S3 method for class 'data.frame'
tif_as_tokens_list(tokens)Details
No explicit checking is done on the input; the output is guaranteed to be valid only if the input is a valid format. In fact, we make an effort to not modify an object that appears to be in the required format already due to R's copy on modify semantics.
Examples
# coerce corpus object
corpus <- c("Aujourd'hui, maman est morte.",
"It was a pleasure to burn.",
"All this happened, more or less.")
names(corpus) <- c("Camus", "Bradbury", "Vonnegut")
new <- tif_as_corpus_df(corpus)
new
#> doc_id text
#> 1 Camus Aujourd'hui, maman est morte.
#> 2 Bradbury It was a pleasure to burn.
#> 3 Vonnegut All this happened, more or less.
tif_as_corpus_character(new)
#> Camus Bradbury
#> "Aujourd'hui, maman est morte." "It was a pleasure to burn."
#> Vonnegut
#> "All this happened, more or less."
# coerce tokens object
tokens <- list(doc1 = c("aujourd'hui", "maman", "est", "morte"),
doc2 = c("it", "was", "a", "pleasure", "to", "burn"),
doc3 = c("all", "this", "happened", "more", "or", "less"))
new <- tif_as_tokens_df(tokens)
new
#> doc_id token
#> 1 doc1 aujourd'hui
#> 2 doc1 maman
#> 3 doc1 est
#> 4 doc1 morte
#> 5 doc2 it
#> 6 doc2 was
#> 7 doc2 a
#> 8 doc2 pleasure
#> 9 doc2 to
#> 10 doc2 burn
#> 11 doc3 all
#> 12 doc3 this
#> 13 doc3 happened
#> 14 doc3 more
#> 15 doc3 or
#> 16 doc3 less
tif_as_tokens_list(new)
#> $doc1
#> [1] "aujourd'hui" "maman" "est" "morte"
#>
#> $doc2
#> [1] "it" "was" "a" "pleasure" "to" "burn"
#>
#> $doc3
#> [1] "all" "this" "happened" "more" "or" "less"
#>