emotional

Subjectivtiy and sentiment/polarity analysis library for Node.js.

Partial port from the pattern.en library of CLIPS (University of Antwerp), so all credits go to the original authors Tom De Smedt and Walter Daelemans. It's based on their own acquired adjective sentiment database.

Explanation taken from their website (and slightly altered to fit this module):

Written text can be broadly categorized into two types: facts and opinions. Opinions carry people's sentiments, appraisals and feelings toward the world. The emotional module bundles a lexicon of adjectives (e.g., good, bad, amazing, irritating, ...) that occur frequently in product reviews, annotated with scores for sentiment polarity (positive ↔ negative) and subjectivity (objective ↔ subjective).

The emotional.get(sentence) function returns a { polarity: [-1, 1], subjectivity: [0, 1], assessments: ...} object for the given sentence, based on the adjectives it contains, where polarity is a value between -1.0 and +1.0 and subjectivity between 0.0 and 1.0. The sentence should be a string.

The emotional.positive(sentence, threshold) function returns True if the given sentence's polarity is above the threshold. The threshold can be lowered or raised, but overall +0.1 gives the best results for product reviews. Accuracy is about 75% for movie reviews.

This sentiment analyzer also incorporates emoticons for mood setting and ! punctuation for enhancement.

Usage

Install with npm:

npm install emotional

Import library and make sure the database is loaded with load. Then start using the get or positive functions on the emotional object.

var emotional = require("emotional");
emotional.load(function () {
  emotional.get("sentence") // { polarity: [-1,1], subjectivity: [0,1], assessments: ... };
  emotional.positive("sentence") // true | false
});

var emotional = require("emotional");
emotional.load(function () {
  emotional.get("The movie attempts to be surreal by incorporating various time paradoxes,"+
                "but it's presented in such a ridiculous way it's seriously boring.")
  // = {
  //    polarity: -0.21
  //    subjectivity: 0.8
  //    assessments:
  //      [['surreal'], 0.25, 1, null],
  //      [['various'], 0, 0.5, null],
  //      [['such'], 0, 0.5, null],
  //      [['ridiculous'], -0.33, 1, null],
  //      [['seriously', 'boring'], -1, 1, null]]);
  //    }
  // i.e. it is a very subjective sentence, expressing a negative opinion.

  emotional.get('Wonderfully awful! :-)');
  // = {
  //    polarity = -0.25,
  //    subjectivity = 1,
  //    assessments = [
  //      [['wonderfully', 'awful', '!'], -1.0, 1.0, null],
  //      [[':-)'], 0.5, 1.0, 'mood']]
  //    };
  // 'wonderfully', 'awful' and '!' are assessed together and analyzed as very subjective and negative

  emotional.get('Today is monday!');
  // = {
  //  polarity = 0,
  //  subjectivity = 0,
  //  assessments = []
  // }
  // Nothing subjective here.

  emotional.positive("This is a good movie") // true
  emotional.positive("this is a bad movie") // false
  emotional.positive("This is a good movie", 0.8) // false
  emotional.positive("This is a really good movie", 0.8) // true
});
)

Test

In order to run the tests, make sure all dependencies are installed with

npm install

and then simply run with

npm test

License (BSD)

Copyright (c) 2011-2013 University of Antwerp, Belgium All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of Pattern nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.