conText (version 1.4.3)

tokens_context: Get the tokens of contexts sorrounding user defined patterns

Description

This function uses quanteda's kwic() function to find the contexts around user defined patterns (i.e. target words/phrases) and return a tokens object with the tokenized contexts and corresponding document variables.

Usage

tokens_context(
  x,
  pattern,
  window = 6L,
  valuetype = c("glob", "regex", "fixed"),
  case_insensitive = TRUE,
  hard_cut = FALSE,
  rm_keyword = TRUE,
  verbose = TRUE
)

Value

a (quanteda) tokens-class. Each document in the output tokens object inherits the document variables (docvars) of the document from whence it came, along with a column registering corresponding the pattern used. This information can be retrieved using docvars().

Arguments

x

a (quanteda) tokens-class object

pattern

a character vector, list of character vectors, dictionary, or collocations object. See pattern for details.

window

the number of context words to be displayed around the keyword

valuetype

the type of pattern matching: "glob" for "glob"-style wildcard expressions; "regex" for regular expressions; or "fixed" for exact matching. See valuetype for details.

case_insensitive

logical; if TRUE, ignore case when matching a pattern or dictionary values

hard_cut

(logical) - if TRUE then a context must have window x 2 tokens, if FALSE it can have window x 2 or fewer (e.g. if a doc begins with a target word, then context will have window tokens rather than window x 2)

rm_keyword

(logical) if FALSE, keyword matching pattern is included in the tokenized contexts

verbose

(logical) if TRUE, report the total number of instances per pattern found

Examples

library(quanteda)

# tokenize corpus
toks <- tokens(cr_sample_corpus)

# build a tokenized corpus of contexts sorrounding a target term
immig_toks <- tokens_context(x = toks, pattern = "immigr*", window = 6L)