as.dictionary.Rd
Convert a dictionary from a different format into a quanteda dictionary, or check to see if an object is a dictionary.
as.dictionary(x, format = c("tidytext"), separator = " ", tolower = FALSE) is.dictionary(x)
x | a dictionary-like object to be coerced or checked |
---|---|
format | input format for the object to be coerced to a
dictionary; current legal values are a data.frame with the fields
|
separator | the character in between multi-word dictionary values. This
defaults to |
tolower | if |
as.dictionary
returns a quanteda dictionary
object. This conversion function differs from the dictionary
constructor function in that it converts an existing object rather than
creates one from components or from a file.
is.dictionary
returns TRUE
if an object is a
quanteda dictionary.
# NOT RUN { data(sentiments, package = "tidytext") as.dictionary(subset(sentiments, lexicon == "nrc")) as.dictionary(subset(sentiments, lexicon == "bing")) # to convert AFINN into polarities - adjust thresholds if desired datafinn <- subset(sentiments, lexicon == "AFINN") datafinn[["sentiment"]] <- with(datafinn, sentiment <- ifelse(score < 0, "negative", ifelse(score > 0, "positive", "netural")) ) with(datafinn, table(score, sentiment)) as.dictionary(datafinn) dat <- data.frame( word = c("Great", "Horrible"), sentiment = c("positive", "negative") ) as.dictionary(dat) as.dictionary(dat, tolower = FALSE) # }#> [1] TRUE#> [1] FALSE# [1] FALSE