R: Identify the most frequent features in a dfm

topfeatures {quanteda} | R Documentation

## Identify the most frequent features in a dfm

### Description

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

### Usage

    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` | grouping variable for sampling, equal in length to the number of documents. This will be evaluated in the docvars data.frame, so that docvars may be referred to by name without quoting. This also changes previous behaviours for `groups`. See `news(Version >= "3.0", package = "quanteda")` 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

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

    # 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))

[Package quanteda version 3.0.0 Index]