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

Understanding matrix operations

I will start with basic matrix definitions, including an orthogonal matrix and determinant. They will help you to understand a transformation matrix and eigenvalues and eigenvectors.

An orthogonal matrix

Let me start with a few matrix definitions. A vector is called “normal” if it has a length of one. Two vectors are “orthogonal” if they are at right angles to each other. A matrix is called an “orthonormal matrix” if it is a real square matrix whose columns and rows are orthonormal vectors. Figure 4.1 gives some examples:

Figure 4.1 – An orthogonal matrix

Figure 4.1 – An orthogonal matrix

Why are we interested in an orthogonal matrix? The product of two orthogonal matrices will also be an orthogonal matrix. The transpose of the orthogonal matrix will also be an orthogonal matrix. These properties will be used to derive SVD.

The determinant of a matrix

The determinant of a matrix is the scalar value...