nlp-toolkit

    0.2.6 • Public • Published

    Natural Language Processing Toolkit for node.js

    This module covers some basic nlp principles and implementations. The main focus is performance. When we deal with sample or training data in nlp, we quickly run out of memory. Therefore every implementation in this module is written as stream to only hold that data in memory that is currently processed at any step.

    Install

    npm install nlp-toolkit
    

    Example

    Frequency distribution of words in texts. Tokenize, remove stopwords, stem words, count words. Traditionally those steps happen sequentially. But we do not need to tokenize the whole text before removing stopwords.

    var nlp = require('nlp-toolkit');
    var fs = require('fs');
    var es = require('event-stream');
     
    fs.createReadStream('./pride_prejudice.txt')
    .pipe(es.split())
    .pipe(nlp.tokenizer())
    .pipe(nlp.stopwords())
    .pipe(nlp.stemmer())
    .pipe(nlp.frequency())
    .on('data', function (freqDist) {
      console.log(freqDist.slice(0, 10));
    })
    .on('error', function (err) {
      console.error(err);
    });

    Modules

    Tokenizer

    .pipe(nlp.tokenizer(options))

    options:

    attribute type description
    characters RegExp regular expression that describes what characters to strip of off (default /[^\w]/g).
    separator RegExp regular expression that describes where to split words (default /\s/g).
    eliminateNumbers boolean discard tokens that only contain numbers (default false).
    toLowerCase boolean transform every token to lower case (default true).
    emptyStrings boolean keep empty string when through some previous steps tokens result in length === 0 (default false).

    Tokenizer also work in a non-stream context:

    var tokens = nlp.tokenizer(string, options);

    Stopwords

    .pipe(nlp.stopwords(options))

    options:

    attribute type description
    defaultLang string default language if processed object does not provide a lang attribute (default en).
    additionalWords object add additional stopwords to the list of stopwords

    additionalWords:

    attribute type description
    all array list of stopwords to add to every language
    default array list of stopwords if language is not supported
    lang array list of stopwords specific to lang

    Supported languages: da, de, en, es, fi, fr, hu, it, nl, no, pt, ro, ru, se, tr.

    Stopwords also work in a non-stream context:

    nlp.stopwords(sentence, options)
    .then(function (tokens) {}})
    .catch(function (err) { console.error(err); });

    Stemmer

    .pipe(nlp.stemmer(options))

    options:

    attribute type description
    defaultStemmer string default stemmer for language if processed object does not provide a lang attribute (default en).

    Supported languages: da, de, en, es, fi, fr, hu, it, nl, no, pt, ro, ru, se, tr.

    Stopwords also work in a non-stream context:

    var tokens = nlp.stemmer(sentence, options);

    This module uses the stemmer implementation of Snowball-Stemmer.

    Frequency Distribution

    .pipe(nlp.frequency())

    Install

    npm i nlp-toolkit

    DownloadsWeekly Downloads

    25

    Version

    0.2.6

    License

    none

    Last publish

    Collaborators

    • amberlamps