using matlab for sentiment analysis and text analytics€¦ · doc2 1 1 0 1 • word docs •...
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1© 2017 The MathWorks, Inc.
Using MATLAB for Sentiment Analysis and Text Analytics
Seth DeLand
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Sentiment Analysis
Understand sentiment of documents, emails, social media
Applications§ Predict prices, inform trading strategies§ Risk analytics§ Economics research§ Litigation
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Text Analytics Toolbox
Media reported two trees blown down along I-40 in the Old Fort area.
Develop Predictive ModelsAccess and Explore Data Preprocess Data
Clean-up Text Convert to Numeric
media report two tree blown down i40 old fort area
cat dog run two
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• Word Docs• PDF’s• Text Files
• Stop Words• Stemming• Tokenization
• Bag of Words• TF-IDF• Word Embeddings
• Latent DirichletAllocation
• Latent Semantic Analysis
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StringsThe better way to work with text
§ Manipulate, compare, and store text data efficiently>> "image" + (1:3) + ".png"
1×3 string array
"image1.png" "image2.png" "image3.png"
§ Simplified text manipulation functions– Example: Check if a string is contained within another string
§ Previously: if ~isempty(strfind(textdata,"Dog"))
§ Now: if contains(textdata,"Dog")
§ Performance improvement– Up to 50x faster using contains with string than strfind with cellstr– Up to 2x memory savings using string over cellstr
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Demo: Sentiment Analysis of Tweets
Goal:§ Analyze the sentiment of tweets for several
tech companies and compare the sentiment scores to stock prices
Approach§ Access data from Twitter§ Preprocess to clean-up text and deal with
domain-specific terms§ Predict sentiment from word embedding § Compare sentiment scores to prices
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Additional Text Analytics Capabilities
§ Extract text from pdf’s and word documents
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Bag of Words Models and TF-IDF
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LSA and LDA
§ Unsupervised machine learning techniques§ Well-suited to wide feature matrices§ Both can be used for dimensionality reduction§ LDA is also useful for topic modeling
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Learn More
https://www.mathworks.com/help/textanalytics/examples.html
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Learn More
https://blogs.mathworks.com/loren/2017/09/21/math-with-words-word-embeddings-with-matlab-and-text-analytics-toolbox/
Math with Words – Word Embeddings with MATLAB and Text Analytics Toolbox
11© 2017 The MathWorks, Inc.
Questions?