A logical value indicating whether punctuation characters should be removed from doc, a custom function which performs punctuation removal, or a list of arguments for removePunctuation. Defaults to FALSE.

A logical value indicating whether numbers should be removed from doc or a custom function for number removal. Defaults to FALSE.

Either a Boolean value indicating stopword removal using default language specific stopword lists shipped with this package, a character vector holding custom stopwords, or a custom function for stopword removal. Defaults to FALSE.

bounds

A list with a tag local whose value must be an integer vector of length 2. Terms that appear less often in doc than the lower bound bounds$local[1] or more often than the upper bound bounds$local[2] are discarded. Defaults to list(local = c(1,Inf)) (i.e., every token will be used).

An integer vector of length 2. Words shorter than the minimum word length wordLengths[1] or longer than the maximum word length wordLengths[2] are discarded. Defaults to c(3, Inf), i.e., a minimum word length of 3 characters.