Book Image

Machine Learning Solutions

Book Image

Machine Learning Solutions

Overview of this book

Machine learning (ML) helps you find hidden insights from your data without the need for explicit programming. This book is your key to solving any kind of ML problem you might come across in your job. You’ll encounter a set of simple to complex problems while building ML models, and you'll not only resolve these problems, but you’ll also learn how to build projects based on each problem, with a practical approach and easy-to-follow examples. The book includes a wide range of applications: from analytics and NLP, to computer vision domains. Some of the applications you will be working on include stock price prediction, a recommendation engine, building a chat-bot, a facial expression recognition system, and many more. The problem examples we cover include identifying the right algorithm for your dataset and use cases, creating and labeling datasets, getting enough clean data to carry out processing, identifying outliers, overftting datasets, hyperparameter tuning, and more. Here, you'll also learn to make more timely and accurate predictions. In addition, you'll deal with more advanced use cases, such as building a gaming bot, building an extractive summarization tool for medical documents, and you'll also tackle the problems faced while building an ML model. By the end of this book, you'll be able to fine-tune your models as per your needs to deliver maximum productivity.
Table of Contents (19 chapters)
Machine Learning Solutions
Foreword
Contributors
Preface
Index

Feature engineering for the baseline model


For this application, we will be using a basic statistical feature extraction concept in order to generate the features from raw text data. In the NLP domain, we need to convert raw text into a numerical format so that the ML algorithm can be applied to that numerical data. There are many techniques available, including indexing, count based vectorization, Term Frequency - Inverse Document Frequency (TF-IDF ), and so on. I have already discussed the concept of TF-IDF in Chapter 4, Generate features using TF-IDF:

Note

Indexing is basically used for fast data retrieval. In indexing, we provide a unique identification number. This unique identification number can be assigned in alphabetical order or based on frequency. You can refer to this link: http://scikit-learn.org/stable/modules/generated/sklearn.preprocessing.LabelEncoder.html

Count-based vectorization sorts the words in alphabetical order and if a particular word is present then its vector value...