Book Image

Machine Learning Algorithms - Second Edition

Book Image

Machine Learning Algorithms - Second Edition

Overview of this book

Machine learning has gained tremendous popularity for its powerful and fast predictions with large datasets. However, the true forces behind its powerful output are the complex algorithms involving substantial statistical analysis that churn large datasets and generate substantial insight. This second edition of Machine Learning Algorithms walks you through prominent development outcomes that have taken place relating to machine learning algorithms, which constitute major contributions to the machine learning process and help you to strengthen and master statistical interpretation across the areas of supervised, semi-supervised, and reinforcement learning. Once the core concepts of an algorithm have been covered, you’ll explore real-world examples based on the most diffused libraries, such as scikit-learn, NLTK, TensorFlow, and Keras. You will discover new topics such as principal component analysis (PCA), independent component analysis (ICA), Bayesian regression, discriminant analysis, advanced clustering, and gaussian mixture. By the end of this book, you will have studied machine learning algorithms and be able to put them into production to make your machine learning applications more innovative.
Table of Contents (19 chapters)

Topic modeling

The main goal of topic modeling in NLP is to analyze a corpus, to identify common topics among documents. In this context, even if we talk about semantics, this concept has a particular meaning, driven by a very important assumption. A topic derives from the usage of particular terms in the same document, and it is confirmed by the multiplicity of different documents where the first condition is true.

In other words, we don't consider human-oriented semantics but a statistical modeling that works with meaningful documents (this guarantees that the usage of terms is aimed to express a particular concept, and, therefore, there's a human semantic purpose behind them). For this reason, the starting point of all our methods is an occurrence matrix, normally defined as a document-term matrix (we have already discussed count vectorizing and TF-IDF in Chapter...