qdap (version 1.3.2)

Filter.TermDocumentMatrix: Filter

Description

Filter.TermDocumentMatrix - Filter words from a TermDocumentMatrix vector that meet max/min word length criteria. Filter.DocumentTermMatrix - Filter words from a DocumentTermMatrix that meet max/min word length criteria. Filter - Filter words from various objects that meet max/min word length criteria. Filter.character - Filter words from a character vector that meet max/min word length criteria.

Usage

## S3 method for class 'TermDocumentMatrix':
Filter(x, min = 1, max = Inf,
  count.apostrophe = TRUE, stopwords = NULL, ignore.case = TRUE, ...)

## S3 method for class 'DocumentTermMatrix':
Filter(x, min = 1, max = Inf,
  count.apostrophe = TRUE, stopwords = NULL, ignore.case = TRUE, ...)

Filter(x, min = 1, max = Inf, count.apostrophe = TRUE, stopwords = NULL,
  ignore.case = TRUE, ...)

## S3 method for class 'character':
Filter(x, min = 1, max = Inf, count.apostrophe = TRUE,
  stopwords = NULL, ignore.case = TRUE, ...)

Arguments

x

A filterable object (e.g., wfm, character).

min

Minimum word length.

max

Maximum word length.

count.apostrophe

logical. If TRUE apostrophes are counted as characters.

stopwords

A vector of stop words to remove.

ignore.case

logical. If TRUE stopwords will be removed regardless of case (ignored if used on a wfm).

...

Other arguments passed to specific Filter methods.

Value

• Filter.TermDocumentMatrix - Returns a matrix of the class "TermDocumentMatrix". Filter.DocumentTermMatrix - Returns a matrix of the class "DocumentTermMatrix". Filter.character - Returns a vector of the class "character". Filter.wfm - Returns a matrix of the class "wfm".

Details

TermDocumentMatrix Method for Filter DocumentTermMatrix Method for Filter character Method for Filter

Examples

Filter(with(DATA, wfm(state, list(sex, adult))), 5)
with(DATA, wfm(state, list(sex, adult)))

## Filter particular words based on max/min values in wfm
v <- with(DATA, wfm(state, list(sex, adult)))
Filter(v, 5)
Filter(v, 5, count.apostrophe = FALSE)
Filter(v, 5, 7)
Filter(v, 4, 4)
Filter(v, 3, 4)
Filter(v, 3, 4, stopwords = Top25Words)

## Filter works on character strings too...
x <- c("Raptors don't like robots!",  "I'd pay $500.00 to rid them.")
Filter(x, 3)
Filter(x, 4)
Filter(x, 4, count.apostrophe = FALSE)
Filter(x, 4, count.apostrophe = FALSE, stopwords="raptors")
Filter(x, 4, stopwords="raptors")
Filter(x, 4, stopwords="raptors", ignore.case = FALSE)

DATA[, "state"] <- Filter(DATA[, "state"], 4)
DATA <- qdap::DATA