Summary
In this chapter, we have examined complex, unstructured data. We cleaned and tokenized text and examined several ways of extracting features from documents in a way that could be incorporated into predictive models such as n-grams and tf-idf scores. We also examined dimensionality reduction techniques, such as the HashingVectorizer, matrix decompositions, such as PCA, CUR, NMF, and probabilistic models, such as LDA. We also examined image data, including normalization and thresholding operations, and how we can use dimensionality reduction techniques to find common patterns among images. Finally, we used a matrix factorization algorithm to prototype a recommender system in PySpark.
In the next section, you will also look at image data, ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access