dictionary: Create a dictionary

In quanteda: Quantitative Analysis of Textual Data

Create a dictionary

Description

Create a quanteda dictionary class object, either from a list or by importing from a foreign format. Currently supported input file formats are the WordStat, LIWC, Lexicoder v2 and v3, and Yoshikoder formats. The import using the LIWC format works with all currently available dictionary files supplied as part of the LIWC 2001, 2007, and 2015 software (see References).

Usage

dictionary(
  x,
  file = NULL,
  format = NULL,
  separator = " ",
  tolower = TRUE,
  encoding = "utf-8"
)

Arguments

x	a named list of character vector dictionary entries, including valuetype pattern matches, and including multi-word expressions separated by concatenator. See examples. This argument may be omitted if the dictionary is read from file.
file	file identifier for a foreign dictionary
format	character identifier for the format of the foreign dictionary. If not supplied, the format is guessed from the dictionary file's extension. Available options are: "wordstat" format used by Provalis Research's WordStat software "LIWC" format used by the Linguistic Inquiry and Word Count software "yoshikoder" format used by Yoshikoder software "lexicoder" format used by Lexicoder "YAML" the standard YAML format
separator	the character in between multi-word dictionary values. This defaults to " ".
tolower	if TRUE, convert all dictionary values to lowercase
encoding	additional optional encoding value for reading in imported dictionaries. This uses the iconv labels for encoding. See the "Encoding" section of the help for file.

Details

Dictionaries can be subsetted using [ and [[, operating the same as the equivalent list operators.

Dictionaries can be coerced from lists using as.dictionary(), coerced to named lists of characters using as.list(), and checked using is.dictionary().

Value

A dictionary class object, essentially a specially classed named list of characters.

References

WordStat dictionaries page, from Provalis Research https://provalisresearch.com/products/content-analysis-software/wordstat-dictionary/.

Pennebaker, J.W., Chung, C.K., Ireland, M., Gonzales, A., & Booth, R.J. (2007). The development and psychometric properties of LIWC2007. [Software manual]. Austin, TX (https://www.liwc.app/).

Yoshikoder page, from Will Lowe https://conjugateprior.org/software/yoshikoder/.

Lexicoder format, https://www.snsoroka.com/data-lexicoder/

See Also

as.dictionary(), as.list(), is.dictionary()

Examples

corp <- corpus_subset(data_corpus_inaugural, Year>1900)
dict <- dictionary(list(christmas = c("Christmas", "Santa", "holiday"),
                          opposition = c("Opposition", "reject", "notincorpus"),
                          taxing = "taxing",
                          taxation = "taxation",
                          taxregex = "tax*",
                          country = "america"))
tokens(corp) |>
    tokens_lookup(dictionary = dict) |>
    dfm()

# subset a dictionary
dict[1:2]
dict[c("christmas", "opposition")]
dict[["opposition"]]

# combine dictionaries
c(dict["christmas"], dict["country"])

## Not run: 
dfmat <- dfm(tokens(data_corpus_inaugural))

# import the Laver-Garry dictionary from Provalis Research
dictfile <- tempfile()
download.file("https://provalisresearch.com/Download/LaverGarry.zip",
              dictfile, mode = "wb")
unzip(dictfile, exdir = (td <- tempdir()))
dictlg <- dictionary(file = paste(td, "LaverGarry.cat", sep = "/"))
dfm_lookup(dfmat, dictlg)

# import a LIWC formatted dictionary from http://www.moralfoundations.org
download.file("http://bit.ly/37cV95h", tf <- tempfile())
dictliwc <- dictionary(file = tf, format = "LIWC")
dfm_lookup(dfmat, dictliwc)

## End(Not run)

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