Book Image

The Handbook of NLP with Gensim

By : Chris Kuo
Book Image

The Handbook of NLP with Gensim

By: Chris Kuo

Overview of this book

Navigating the terrain of NLP research and applying it practically can be a formidable task made easy with The Handbook of NLP with Gensim. This book demystifies NLP and equips you with hands-on strategies spanning healthcare, e-commerce, finance, and more to enable you to leverage Gensim in real-world scenarios. You’ll begin by exploring motives and techniques for extracting text information like bag-of-words, TF-IDF, and word embeddings. This book will then guide you on topic modeling using methods such as Latent Semantic Analysis (LSA) for dimensionality reduction and discovering latent semantic relationships in text data, Latent Dirichlet Allocation (LDA) for probabilistic topic modeling, and Ensemble LDA to enhance topic modeling stability and accuracy. Next, you’ll learn text summarization techniques with Word2Vec and Doc2Vec to build the modeling pipeline and optimize models using hyperparameters. As you get acquainted with practical applications in various industries, this book will inspire you to design innovative projects. Alongside topic modeling, you’ll also explore named entity handling and NER tools, modeling procedures, and tools for effective topic modeling applications. By the end of this book, you’ll have mastered the techniques essential to create applications with Gensim and integrate NLP into your business processes.
Table of Contents (24 chapters)
1
Part 1: NLP Basics
5
Part 2: Latent Semantic Analysis/Latent Semantic Indexing
9
Part 3: Word2Vec and Doc2Vec
12
Part 4: Topic Modeling with Latent Dirichlet Allocation
18
Part 5: Comparison and Applications

Chapter 4 – Latent Semantic Analysis with scikit-learn

  1. An orthonormal matrix is a real square matrix whose columns and rows are orthogonal vectors.
  2. A transformation matrix is a matrix that can transform one vector into another vector through matrix multiplication.
  3. An important application of a transformation matrix is image transformation. Convex mirrors can distort an image to make it larger or smaller. A convex safety mirror or security mirror can show a wide angle of view.
  4. SVD is a matrix decomposition method that can reduce a large, usually sparse, matrix into three sub-matrices.
  5. In short, SVD can decompose an original sparse document-word matrix into three matrices. The first matrix is a document-topic matrix, the second matrix is a square topic-topic matrix, and the third matrix is a topic-word matrix.
  6. The topic-word matrix relates latent topic to words.
  7. The text variance that can be explained by the latent topics can be obtained by obtaining...