/*
* Copyright 2016 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
var Utils = require('../../utils.js');
var LDAModel = require('./LDAModel.js');
var gKernelP;
/**
* Latent Dirichlet Allocation (LDA), a topic model designed for text documents.
*
* Terminology:
* - "word" = "term": an element of the vocabulary
* - "token": instance of a term appearing in a document
* - "topic": multinomial distribution over words representing some concept
*
* References:
* - Original LDA paper (journal version):
* Blei, Ng, and Jordan. "Latent Dirichlet Allocation." JMLR, 2003.
*
* @see [[http://en.wikipedia.org/wiki/Latent_Dirichlet_allocation Latent Dirichlet allocation
* (Wikipedia)]]
* @classdesc
*/
/**
* Constructs a LDA instance with default parameters.
* @returns {??}
* @class
* @memberof module:eclairjs/mllib/clustering
*/
function LDA() {
Utils.handleConstructor(this, arguments, gKernelP);
}
/**
* Number of topics to infer. I.e., the number of soft cluster centers.
*
* @returns {Promise.<number>}
*/
LDA.prototype.getK = function() {
throw "not implemented by ElairJS";
};
/**
* Number of topics to infer. I.e., the number of soft cluster centers.
* (default = 10)
* @param {number} k
* @returns {module:eclairjs/mllib/clustering.LDA}
*/
LDA.prototype.setK = function(k) {
var args = {
target: this,
method: 'setK',
args: Utils.wrapArguments(arguments),
returnType: LDA
};
return Utils.generate(args);
};
/**
* Concentration parameter (commonly named "alpha") for the prior placed on documents'
* distributions over topics ("theta").
*
* This is the parameter to a Dirichlet distribution.
* @returns {module:eclairjs/mllib/linalg.Vector}
*/
LDA.prototype.getAsymmetricDocConcentration = function() {
throw "not implemented by ElairJS";
};
/**
* Concentration parameter (commonly named "alpha") for the prior placed on documents'
* distributions over topics ("theta").
*
* This method assumes the Dirichlet distribution is symmetric and can be described by a single
* {@link Double} parameter. It should fail if docConcentration is asymmetric.
* @returns {Promise.<number>}
*/
LDA.prototype.getDocConcentration = function() {
throw "not implemented by ElairJS";
};
/**
* Concentration parameter (commonly named "alpha") for the prior placed on documents'
* distributions over topics ("theta").
*
* This is the parameter to a Dirichlet distribution, where larger values mean more smoothing
* (more regularization).
*
* If set to a singleton vector Vector(-1), then docConcentration is set automatically. If set to
* singleton vector Vector(t) where t != -1, then t is replicated to a vector of length k during
* [[LDAOptimizer.initialize()]]. Otherwise, the {@link docConcentration} vector must be length k.
* (default = Vector(-1) = automatic)
*
* Optimizer-specific parameter settings:
* - EM
* - Currently only supports symmetric distributions, so all values in the vector should be
* the same.
* - Values should be > 1.0
* - default = uniformly (50 / k) + 1, where 50/k is common in LDA libraries and +1 follows
* from Asuncion et al. (2009), who recommend a +1 adjustment for EM.
* - Online
* - Values should be >= 0
* - default = uniformly (1.0 / k), following the implementation from
* [[https://github.com/Blei-Lab/onlineldavb]].
* @param {module:eclairjs/mllib/linalg.Vector} docConcentration
* @returns {}
*/
LDA.prototype.setDocConcentrationwithVector = function(docConcentration) {
throw "not implemented by ElairJS";
};
/**
* Replicates a {@link Double} docConcentration to create a symmetric prior.
* @param {number} docConcentration
* @returns {}
*/
LDA.prototype.setDocConcentrationwithnumber = function(docConcentration) {
throw "not implemented by ElairJS";
};
/**
* Alias for {@link getAsymmetricDocConcentration}
* @returns {module:eclairjs/mllib/linalg.Vector}
*/
LDA.prototype.getAsymmetricAlpha = function() {
throw "not implemented by ElairJS";
};
/**
* Alias for {@link getDocConcentration}
* @returns {Promise.<number>}
*/
LDA.prototype.getAlpha = function() {
throw "not implemented by ElairJS";
};
/**
* Alias for [[setDocConcentration()]]
* @param {module:eclairjs/mllib/linalg.Vector} alpha
* @returns {}
*/
LDA.prototype.setAlphawithVector = function(alpha) {
throw "not implemented by ElairJS";
};
/**
* Alias for [[setDocConcentration()]]
* @param {number} alpha
* @returns {}
*/
LDA.prototype.setAlphawithnumber = function(alpha) {
throw "not implemented by ElairJS";
};
/**
* Concentration parameter (commonly named "beta" or "eta") for the prior placed on topics'
* distributions over terms.
*
* This is the parameter to a symmetric Dirichlet distribution.
*
* Note: The topics' distributions over terms are called "beta" in the original LDA paper
* by Blei et al., but are called "phi" in many later papers such as Asuncion et al., 2009.
* @returns {Promise.<number>}
*/
LDA.prototype.getTopicConcentration = function() {
throw "not implemented by ElairJS";
};
/**
* Concentration parameter (commonly named "beta" or "eta") for the prior placed on topics'
* distributions over terms.
*
* This is the parameter to a symmetric Dirichlet distribution.
*
* Note: The topics' distributions over terms are called "beta" in the original LDA paper
* by Blei et al., but are called "phi" in many later papers such as Asuncion et al., 2009.
*
* If set to -1, then topicConcentration is set automatically.
* (default = -1 = automatic)
*
* Optimizer-specific parameter settings:
* - EM
* - Value should be > 1.0
* - default = 0.1 + 1, where 0.1 gives a small amount of smoothing and +1 follows
* Asuncion et al. (2009), who recommend a +1 adjustment for EM.
* - Online
* - Value should be >= 0
* - default = (1.0 / k), following the implementation from
* [[https://github.com/Blei-Lab/onlineldavb]].
* @param {number} topicConcentration
* @returns {}
*/
LDA.prototype.setTopicConcentration = function(topicConcentration) {
throw "not implemented by ElairJS";
};
/**
* Alias for {@link getTopicConcentration}
* @returns {Promise.<number>}
*/
LDA.prototype.getBeta = function() {
throw "not implemented by ElairJS";
};
/**
* Alias for [[setTopicConcentration()]]
* @param {number} beta
* @returns {}
*/
LDA.prototype.setBeta = function(beta) {
throw "not implemented by ElairJS";
};
/**
* Maximum number of iterations for learning.
* @returns {Promise.<number>}
*/
LDA.prototype.getMaxIterations = function() {
throw "not implemented by ElairJS";
};
/**
* Maximum number of iterations for learning.
* (default = 20)
* @param {number} maxIterations
* @returns {}
*/
LDA.prototype.setMaxIterations = function(maxIterations) {
throw "not implemented by ElairJS";
};
/**
* Random seed
* @returns {Promise.<number>}
*/
LDA.prototype.getSeed = function() {
throw "not implemented by ElairJS";
};
/**
* Random seed
* @param {number} seed
* @returns {}
*/
LDA.prototype.setSeed = function(seed) {
throw "not implemented by ElairJS";
};
/**
* Period (in iterations) between checkpoints.
* @returns {Promise.<number>}
*/
LDA.prototype.getCheckpointInterval = function() {
throw "not implemented by ElairJS";
};
/**
* Period (in iterations) between checkpoints (default = 10). Checkpointing helps with recovery
* (when nodes fail). It also helps with eliminating temporary shuffle files on disk, which can be
* important when LDA is run for many iterations. If the checkpoint directory is not set in
* {@link SparkContext}, this setting is ignored.
*
* @see [[org.apache.spark.SparkContext#setCheckpointDir]]
* @param {number} checkpointInterval
* @returns {}
*/
LDA.prototype.setCheckpointInterval = function(checkpointInterval) {
throw "not implemented by ElairJS";
};
/**
* Set the LDAOptimizer used to perform the actual calculation by algorithm name.
* Currently "em", "online" are supported.
* @param {string} optimizerName
* @returns {}
*/
LDA.prototype.setOptimizer = function(optimizerName) {
throw "not implemented by ElairJS";
};
/**
* Learn an LDA model using the given dataset.
*
* @param {module:eclairjs/rdd.RDD} documents RDD of documents, which are term (word) count vectors paired with IDs.
* The term count vectors are "bags of words" with a fixed-size vocabulary
* (where the vocabulary size is the length of the vector).
* Document IDs must be unique and >= 0.
* @returns {module:eclairjs/mllib/clustering.LDAModel} Inferred LDA model
*/
LDA.prototype.run = function(documents) {
var args = {
target: this,
method: 'run',
args: Utils.wrapArguments(arguments),
returnType: LDAModel
};
return Utils.generate(args);
};
LDA.moduleLocation = '/mllib/clustering/LDA';
module.exports = function(kP) {
if (kP) gKernelP = kP;
return LDA;
};