quanteda: tokens_sample – R documentation

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tokens_sample

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)

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.

Value

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

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

Quantitative Analysis of Textual Data

v3.0.0

GPL-3

Authors

Kenneth Benoit [cre, aut, cph] (<https://orcid.org/0000-0002-0797-564X>), Kohei Watanabe [aut] (<https://orcid.org/0000-0001-6519-5265>), Haiyan Wang [aut] (<https://orcid.org/0000-0003-4992-4311>), Paul Nulty [aut] (<https://orcid.org/0000-0002-7214-4666>), Adam Obeng [aut] (<https://orcid.org/0000-0002-2906-4775>), Stefan Müller [aut] (<https://orcid.org/0000-0002-6315-4125>), Akitaka Matsuo [aut] (<https://orcid.org/0000-0002-3323-6330>), William Lowe [aut] (<https://orcid.org/0000-0002-1549-6163>), Christian Müller [ctb], European Research Council [fnd] (ERC-2011-StG 283794-QUANTESS)

Initial release