In paithiov909/gibasa: An Alternative 'Rcpp' Wrapper of 'MeCab'

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gibasa

Overview

gibasa is a plain 'Rcpp' wrapper for 'MeCab', a morphological analyzer for CJK text.

Part-of-speech tagging with morphological analyzers is useful for processing CJK text data. This is because most words in CJK text are not separated by whitespaces and tokenizers::tokenize_words may split them into wrong tokens.

The main goal of gibasa package is to provide an alternative to tidytext::unnest_tokens for CJK text data. For this goal, gibasa provides three main functions: gibasa::tokenize, gibasa::prettify, and gibasa::pack.

• gibasa::tokenize takes a TIF-compliant data.frame of corpus, returning tokens as format that known as 'tidy text data', so that users can replace tidytext::unnest_tokens with it for tokenizing CJK text.
• gibasa::prettify turns tagged features into columns.
• gibasa::pack takes a 'tidy text data', typically returning space-separated corpus.

Installation

You can install binary package via CRAN or r-universe.

## Install gibasa from r-universe repository
install.packages("gibasa", repos = c("https://paithiov909.r-universe.dev", "https://cloud.r-project.org"))

## Or build from source package
Sys.setenv(MECAB_DEFAULT_RC = "/fullpath/to/your/mecabrc") # if necessary
remotes::install_github("paithiov909/gibasa")

To use gibasa package requires the MeCab library and its dictionary installed and available.

In case using Linux or macOS, you can install them with their package managers, or build and install from the source by yourself.

In case using Windows, use installer built for 64bit. Note that gibasa requires a UTF-8 dictionary, not a Shift-JIS one.

As of v0.9.4, gibasa looks at the file specified by the environment variable MECABRC or the file located at ~/.mecabrc. If the MeCab dictionary is in a different location than the default, create a mecabrc file and specify where the dictionary is located.

For example, to install and use the ipadic from PyPI, run:

$ python3 -m pip install ipadic
$ python3 -c "import ipadic; print('dicdir=' + ipadic.DICDIR);" > ~/.mecabrc

Usage

Tokenize sentences

res <- gibasa::tokenize(
  data.frame(
    doc_id = seq_along(gibasa::ginga[5:8]),
    text = gibasa::ginga[5:8]
  ),
  text,
  doc_id
)
res

Prettify output

gibasa::prettify(res)
gibasa::prettify(res, col_select = 1:3)
gibasa::prettify(res, col_select = c(1, 3, 5))
gibasa::prettify(res, col_select = c("POS1", "Original"))

Pack output

res <- gibasa::prettify(res)
gibasa::pack(res)

dplyr::mutate(
  res,
  token = dplyr::if_else(is.na(Original), token, Original),
  token = paste(token, POS1, sep = "/")
) |>
  gibasa::pack() |>
  head(1L)

Change dictionary

IPA, UniDic, CC-CEDICT-MeCab, and mecab-ko-dic schemes are supported.

## UniDic 2.1.2
gibasa::tokenize("あのイーハトーヴォのすきとおった風", sys_dic = file.path("mecab/unidic-lite")) |>
  gibasa::prettify(into = gibasa::get_dict_features("unidic26"))


## CC-CEDICT
gibasa::tokenize("它可以进行日语和汉语的语态分析", sys_dic = file.path("mecab/cc-cedict")) |>
  gibasa::prettify(into = gibasa::get_dict_features("cc-cedict"))


## mecab-ko-dic
gibasa::tokenize("하네다공항한정토트백", sys_dic = file.path("mecab/mecab-ko-dic")) |>
  gibasa::prettify(into = gibasa::get_dict_features("ko-dic"))

Build dictionaries

Build a system dictionary

## build a new ipadic in temporary directory
build_sys_dic(
  dic_dir = file.path("mecab/ipadic-eucjp"), # replace here with path to your source dictionary
  out_dir = tempdir(),
  encoding = "euc-jp" # encoding of source csv files
)

## copy the 'dicrc' file
file.copy(file.path("mecab/ipadic-eucjp/dicrc"), tempdir())

dictionary_info(sys_dic = tempdir())

Build a user dictionary

## write a csv file and compile it into a user dictionary
writeLines(
  c(
    "月ノ,1290,1290,4579,名詞,固有名詞,人名,姓,*,*,月ノ,ツキノ,ツキノ",
    "美兎,1291,1291,8561,名詞,固有名詞,人名,名,*,*,美兎,ミト,ミト"
  ),
  con = (csv_file <- tempfile(fileext = ".csv"))
)
build_user_dic(
  dic_dir = file.path("mecab/ipadic-eucjp"),
  file = (user_dic <- tempfile(fileext = ".dic")),
  csv_file = csv_file,
  encoding = "utf8"
)

tokenize("月ノ美兎は箱の中", sys_dic = tempdir(), user_dic = user_dic)

License

GPL (>=3).

paithiov909/gibasa documentation built on June 14, 2025, 4:31 p.m.