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Quantitative Finance · शब्दावली

Topic model, latent Dirichlet allocation क्या है?

अन्य नाम: topic model · latent Dirichlet allocation

Definition 13.2 Machine Learning for Markets · अध्याय 13 — Text: From Bag of Words to Embeddings

A topic model describes each document as a mixture of a few topics, each topic a distribution over words, all estimated from word counts without labels. Latent Dirichlet allocation (LDA) is the Bayesian topic model in which each document’s topic shares and each topic’s word probabilities have Dirichlet priors, and each word is drawn by first drawing its topic from the document’s shares (Blei, Ng and Jordan, 2002).

topicsix most probable words
1analysts, fell, short, expectations, forecasts, exceeded
2outlook, guidance, but, expectations, forecasts, estimates
3annual, meeting, record, attendance, reports, holds
4full, forecast, year, reports, line, costs
5wins, authorises, program, repurchase, industry, award
6announces, gets, rating, earnings, schedules, call
Table 13.2. Six topics fitted by LDA to the training headlines (the company placeholder, prepositions and context words removed). Data: ml_text.topics.
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