topfeatures: Identify the most frequent features in a dfm

Description Usage Arguments Value Examples

View source: R/dfm-methods.R

Description

List the most (or least) frequently occurring features in a dfm, either as a whole or separated by document.

Usage

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topfeatures(x, n = 10, decreasing = TRUE, scheme = c("count",
  "docfreq"), groups = NULL)

Arguments

x

the object whose features will be returned

n

how many top features should be returned

decreasing

If TRUE, return the n most frequent features; otherwise return the n least frequent features

scheme

one of count for total feature frequency (within group if applicable), or docfreq for the document frequencies of features

groups

either: a character vector containing the names of document variables to be used for grouping; or a factor or object that can be coerced into a factor equal in length or rows to the number of documents. See groups for details.

Value

A named numeric vector of feature counts, where the names are the feature labels, or a list of these if groups is given.

Examples

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dfmat1 <- corpus_subset(data_corpus_inaugural, Year > 1980) %>%
    dfm(remove_punct = TRUE)
dfmat2 <- dfm_remove(dfmat1, stopwords("english"))

# most frequent features
topfeatures(dfmat1)
topfeatures(dfmat2)

# least frequent features
topfeatures(dfmat2, decreasing = FALSE)

# top features of individual documents  
topfeatures(dfmat2, n = 5, groups = docnames(dfmat2))

# grouping by president last name
topfeatures(dfmat2, n = 5, groups = "President")

# features by document frequencies
tail(topfeatures(dfmat1, scheme = "docfreq", n = 200))

quanteda/quanteda documentation built on Feb. 16, 2019, 5:45 a.m.