read.corp.LCC {koRpus}

Import LCC data

Description

Read data from LCC[1] formatted corpora (Quasthoff, Richter & Biemann, 2006).

Usage

read.corp.LCC(
  LCC.path,
  format = "flatfile",
  fileEncoding = "UTF-8",
  n = -1,
  keep.temp = FALSE,
  prefix = NULL,
  bigrams = FALSE,
  cooccurence = FALSE,
  caseSens = TRUE
)

Arguments

LCC.path

A character string, either path to a .tar/.tar.gz/.zip file in LCC format (flatfile), or the path to the directory with the unpacked archive.

format

Either "flatfile" or "MySQL", depending on the type of LCC data.

fileEncoding

A character string naming the encoding of the LCC files. Old zip archives used "ISO_8859-1". This option will only influence the reading of meta information, as the actual database encoding is derived from there.

n

An integer value defining how many lines of data should be read if format="flatfile". Reads all at -1.

keep.temp

Logical. If LCC.path is a tarred/zipped archive, setting keep.temp=TRUE will keep the temporarily unpacked files for further use. By default all temporary files will be removed when the function ends.

prefix

Character string, giving the prefix for the file names in the archive. Needed for newer LCC tar archives if they are already decompressed (autodetected if LCC.path points to the tar archive directly).

bigrams

Logical, whether infomration on bigrams should be imported. This is FALSE by default, because it might make the objects quite large. Note that this will only work in n = -1 because otherwise the tokens cannot be looked up.

cooccurence

Logical, like bigrams, but for information on co-occurences of tokens in a sentence.

caseSens

Logical, if FALSE forces all frequency statistics to be calculated regardless of the tokens' case. Otherwise, if the imported database supports it, you will get different frequencies for the same tokens in different cases (e.\,g., "one" and "One").

Details

The LCC database can either be unpacked or still a .tar/.tar.gz/.zip archive. If the latter is the case, then all necessary files will be extracted to a temporal location automatically, and by default removed again when the function has finished reading from it.

Newer LCC archives no longer feature the *-meta.txt file, resulting in less meta informtion in the object. In these cases, the total number of tokens is calculated as the sum of types' frequencies.

Value

An object of class kRp.corp.freq.

Note

Please note that MySQL support is not implemented yet.

References

Quasthoff, U., Richter, M. & Biemann, C. (2006). Corpus Portal for Search in Monolingual Corpora, In Proceedings of the Fifth International Conference on Language Resources and Evaluation, Genoa, 1799–1802.

[1] https://wortschatz.uni-leipzig.de/en/download/

See Also

kRp.corp.freq

Examples

## Not run: 
# old format .zip archive
my.LCC.data <- read.corp.LCC(
  file.path("~","mydata","corpora","de05_3M.zip")
)
# new format tar archive
my.LCC.data <- read.corp.LCC(
  file.path("~","mydata","corpora","rus_web_2002_300K-text.tar")
)
# in case the tar archive was already unpacked
my.LCC.data <- read.corp.LCC(
  file.path("~","mydata","corpora","rus_web_2002_300K-text"),
  prefix="rus_web_2002_300K-"
)
freq.analysis(
  tokenized.obj,
  corp.freq=my.LCC.data
)

## End(Not run)