tokens_sample: Randomly sample documents from a tokens object

In quanteda: Quantitative Analysis of Textual Data

Randomly sample documents from a tokens object

Description

Take a random sample of documents of the specified size from a corpus, with or without replacement, optionally by grouping variables or with probability weights.

Usage

tokens_sample(
  x,
  size = NULL,
  replace = FALSE,
  prob = NULL,
  by = NULL,
  env = NULL
)

Arguments

x	a tokens object whose documents will be sampled
size	a positive number, the number of documents to select; when used with by, the number to select from each group or a vector equal in length to the number of groups defining the samples to be chosen in each category of by. By defining a size larger than the number of documents, it is possible to oversample when replace = TRUE.
replace	if TRUE, sample with replacement
prob	a vector of probability weights for obtaining the elements of the vector being sampled. May not be applied when by is used.
by	optional grouping variable for sampling. 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 by. See news(Version >= "2.9", package = "quanteda") for details.
env	an environment or a list object in which x is searched. Passed to substitute for non-standard evaluation.

Value

a tokens object (re)sampled on the documents, containing the document variables for the documents sampled.

See Also

sample

Examples

set.seed(123)
toks <- tokens(data_corpus_inaugural[1:6])
toks
tokens_sample(toks)
tokens_sample(toks, replace = TRUE) |> docnames()
tokens_sample(toks, size = 3, replace = TRUE) |> docnames()

# sampling using by
docvars(toks)
tokens_sample(toks, size = 2, replace = TRUE, by = Party) |> docnames()

quanteda documentation built on Sept. 11, 2024, 6:08 p.m.