quanteda (version 0.9.2-0)

sample.corpus: Randomly sample documents or features

Description

Takes a random sample or documents or features of the specified size from a corpus or document-feature matrix, with or without replacement

Usage

## S3 method for class 'corpus':
sample(x, size = ndoc(x), replace = FALSE, prob = NULL,
  ...)
sample(x, size, replace = FALSE, prob = NULL, ...)
## S3 method for class 'default':
sample(x, size, replace = FALSE, prob = NULL, ...)
## S3 method for class 'dfm':
sample(x, size = ndoc(x), replace = FALSE, prob = NULL,
  what = c("documents", "features"), ...)

Arguments

x

a corpus or dfm object whose documents or features will be sampled

size

a positive number, the number of documents to select

replace

Should sampling be with replacement?

prob

A vector of probability weights for obtaining the elements of the vector being sampled.

...

unused sample, which is not defined as a generic method in the base package.

what

dimension (of a dfm) to sample: can be documents or features

Value

• A corpus object with number of documents equal to size, drawn from the corpus x. The returned corpus object will contain all of the meta-data of the original corpus, and the same document variables for the documents selected.

  A dfm object with number of documents equal to size, drawn from the corpus x. The returned corpus object will contain all of the meta-data of the original corpus, and the same document variables for the documents selected.

See Also

sample

sample

Examples

# sampling from a corpus
summary(sample(inaugCorpus, 5)) 
summary(sample(inaugCorpus, 10, replace=TRUE))
# sampling from a dfm
myDfm <- dfm(inaugTexts[1:10], verbose = FALSE)
sample(myDfm)[, 1:10]
sample(myDfm, replace = TRUE)[, 1:10]
sample(myDfm, what = "features")[1:10, ]