jst_reversed: Run a reversed Joint Sentiment Topic model

In rJST: Joint Sentiment Topic Modelling

Description

Estimates a reversed joint sentiment topic model using a Gibbs sampler, see Details for model description.

Usage

jst_reversed(
  dfm,
  sentiLexInput = NULL,
  numSentiLabs = 3,
  numTopics = 10,
  numIters = 3,
  updateParaStep = -1,
  alpha = -1,
  beta = -1,
  gamma = -1,
  excludeNeutral = FALSE
)

Arguments

dfm	A quanteda dfm object
sentiLexInput	Optional: A quanteda dictionary object for semi-supervised learning. If a dictionary is used, numSentiLabs will be overridden by the number of categories in the dictionary object. An extra category will by default be added for neutral words. This can be turned off by setting excludeNeutral = TRUE.
numSentiLabs	Integer, the number of sentiment labels (defaults to 3)
numTopics	Integer, the number of topics (defaults to 10)
numIters	Integer, the number of iterations (defaults to 3 for test runs, optimize by hand)
updateParaStep	Integer. The number of iterations between optimizations of hyperparameter alpha
alpha	Double, hyperparameter for (defaults to .05*(average docsize/number of topics))
beta	Double, hyperparameter for (defaults to .01, with multiplier .9/.1 for sentiment dictionary presence)
gamma	Double, hyperparameter for (defaults to .05 * (average docsize/number of sentitopics)
excludeNeutral	Boolean. If a dictionary is used, an extra category is added for neutral words. Words in the dictionary receive a low probability of being allocated there. If this is set to TRUE, the neutral sentiment category will be omitted. The variable is irrelevant if no dictionary is used. Defaults to FALSE.

Details

Lin, C., He, Y., Everson, R. and Ruger, S., 2012. Weakly supervised joint sentiment-topic detection from text. IEEE Transactions on Knowledge and Data engineering, 24(6), pp.1134-1145.

Value

A JST_reversed.result object containing a data.frame for each estimated parameter

Examples

model <- jst(quanteda::dfm(quanteda::data_corpus_irishbudget2010),
             paradigm(),
             numTopics = 5,
             numIters = 150)

rJST documentation built on Feb. 13, 2020, 5:08 p.m.