polmineR (version 0.8.0)

kwic: Perform keyword-in-context (KWIC) analysis.

Description

Get concordances for the matches for a query / perform keyword-in-context (kwic) analysis.

Usage

kwic(.Object, ...)
# S4 method for context
kwic(.Object,
  s_attributes = getOption("polmineR.meta"), cpos = TRUE,
  verbose = FALSE, ...)
# S4 method for slice
kwic(.Object, query, cqp = is.cqp,
  left = getOption("polmineR.left"),
  right = getOption("polmineR.right"),
  s_attributes = getOption("polmineR.meta"), p_attribute = "word",
  boundary = NULL, cpos = TRUE, stoplist = NULL,
  positivelist = NULL, regex = FALSE, verbose = TRUE, ...)
# S4 method for partition
kwic(.Object, query, cqp = is.cqp,
  left = getOption("polmineR.left"),
  right = getOption("polmineR.right"),
  s_attributes = getOption("polmineR.meta"), p_attribute = "word",
  boundary = NULL, cpos = TRUE, stoplist = NULL,
  positivelist = NULL, regex = FALSE, verbose = TRUE, ...)
# S4 method for subcorpus
kwic(.Object, query, cqp = is.cqp,
  left = getOption("polmineR.left"),
  right = getOption("polmineR.right"),
  s_attributes = getOption("polmineR.meta"), p_attribute = "word",
  boundary = NULL, cpos = TRUE, stoplist = NULL,
  positivelist = NULL, regex = FALSE, verbose = TRUE, ...)
# S4 method for corpus
kwic(.Object, query, cqp = is.cqp, check = TRUE,
  left = as.integer(getOption("polmineR.left")),
  right = as.integer(getOption("polmineR.right")),
  s_attributes = getOption("polmineR.meta"), p_attribute = "word",
  boundary = NULL, cpos = TRUE, stoplist = NULL,
  positivelist = NULL, regex = FALSE, verbose = TRUE,
  progress = TRUE, ...)
# S4 method for character
kwic(.Object, query, cqp = is.cqp, check = TRUE,
  left = as.integer(getOption("polmineR.left")),
  right = as.integer(getOption("polmineR.right")),
  s_attributes = getOption("polmineR.meta"), p_attribute = "word",
  boundary = NULL, cpos = TRUE, stoplist = NULL,
  positivelist = NULL, regex = FALSE, verbose = TRUE,
  progress = TRUE, ...)
# S4 method for remote_corpus
kwic(.Object, ...)
# S4 method for remote_partition
kwic(.Object, ...)

Arguments

.Object

A (length-one) character vector with the name of a CWB corpus, a partition or context object.

...

Further arguments, used to ensure backwards compatibility. If .Object is a remote_corpus of remote_partition object, the three dots (...) are used to pass arguments. Hence, it is necessary to state the names of all arguments to be passed explicity.

s_attributes

Structural attributes (s-attributes) to include into output table as metainformation.

cpos

Logical, if TRUE, the corpus positions ("cpos") if the hits will be included in the kwic-object that is returned.

verbose

A logical value, whether to print messages.

query

A query, CQP-syntax can be used.

cqp

Either a logical value (TRUE if query is a CQP query), or a function to check whether query is a CQP query or not (defaults to auxiliary function is.query).

left

Number of tokens to the left of query match.

right

Number of tokens to the right of query match.

p_attribute

The p-attribute, defaults to 'word'.

boundary

If provided, a length-one character vector stating an s-attribute that will be used to check the boundaries of the text.

stoplist

Terms or ids to prevent a concordance from occurring in results.

positivelist

Terms or ids required for a concordance to occurr in results

regex

Logical, whether stoplist/positivelist is interpreted as regular expression.

check

A logical value, whether to check validity of CQP query using check_cqp_query.

progress

A logical value, whether to show progress bar.

Value

If there are no matches, or if all (initial) matches are dropped due to the application of a positivelist, a NULL is returned.

Details

The method works with a whole CWB corpus defined by a character vector, and can be applied on a partition- or a context object.

If a positivelist is supplied, only those concordances will be kept that have one of the terms from the positivelist occurr in the context of the query match. Use argument regex if the positivelist should be interpreted as regular expressions. Tokens from the positivelist will be highlighted in the output table.

If a negativelist is supplied, concordances are removed if any of the tokens of the negativelist occurrs in the context of the query match.

References

Baker, Paul (2006): Using Corpora in Discourse Analysis. London: continuum, pp. 71-93 (ch. 4).

Jockers, Matthew L. (2014): Text Analysis with R for Students of Literature. Cham et al: Springer, pp. 73-87 (chs. 8 & 9).

See Also

The return value is a kwic-class object; the documentation for the class explains the standard generic methods applicable to kwic-class objects. It is possible to read the whole text where a query match occurs, see the read-method. To highlight terms in the context of a query match, see the highlight-method.

Examples

# NOT RUN {
use("polmineR")

# basic usage
K <- kwic("GERMAPARLMINI", "Integration")
if (interactive()) show(K)
oil <- corpus("REUTERS") %>% kwic(query = "oil")
if (interactive()) show(oil)
oil <- corpus("REUTERS") %>%
  kwic(query = "oil") %>%
  highlight(yellow = "crude")
if (interactive()) show(oil)

# increase left and right context and display metadata
K <- kwic(
  "GERMAPARLMINI",
  "Integration", left = 20, right = 20,
  s_attributes = c("date", "speaker", "party")
)
if (interactive()) show(K)

# use CQP syntax for matching
K <- kwic(
  "GERMAPARLMINI",
  '"Integration" [] "(Menschen|Migrant.*|Personen)"', cqp = TRUE,
  left = 20, right = 20,
  s_attributes = c("date", "speaker", "party")
)
if (interactive()) show(K)

# check that boundary of region is not transgressed
K <- kwic(
  "GERMAPARLMINI",
  '"Sehr" "geehrte"', cqp = TRUE,
  left = 100, right = 100,
  boundary = "date"
)
if (interactive()) show(K)

# use positivelist and highlight matches in context
K <- kwic("GERMAPARLMINI", query = "Integration", positivelist = "[Ee]urop.*", regex = TRUE)
K <- highlight(K, yellow = "[Ee]urop.*", regex = TRUE)

# }