Book Image

Essential Statistics for Non-STEM Data Analysts

By : Rongpeng Li
Book Image

Essential Statistics for Non-STEM Data Analysts

By: Rongpeng Li

Overview of this book

Statistics remain the backbone of modern analysis tasks, helping you to interpret the results produced by data science pipelines. This book is a detailed guide covering the math and various statistical methods required for undertaking data science tasks. The book starts by showing you how to preprocess data and inspect distributions and correlations from a statistical perspective. You’ll then get to grips with the fundamentals of statistical analysis and apply its concepts to real-world datasets. As you advance, you’ll find out how statistical concepts emerge from different stages of data science pipelines, understand the summary of datasets in the language of statistics, and use it to build a solid foundation for robust data products such as explanatory models and predictive models. Once you’ve uncovered the working mechanism of data science algorithms, you’ll cover essential concepts for efficient data collection, cleaning, mining, visualization, and analysis. Finally, you’ll implement statistical methods in key machine learning tasks such as classification, regression, tree-based methods, and ensemble learning. By the end of this Essential Statistics for Non-STEM Data Analysts book, you’ll have learned how to build and present a self-contained, statistics-backed data product to meet your business goals.
Table of Contents (19 chapters)
1
Section 1: Getting Started with Statistics for Data Science
5
Section 2: Essentials of Statistical Analysis
10
Section 3: Statistics for Machine Learning
15
Section 4: Appendix

Learning regularization from logistic regression examples

L-1 norm regularization, which penalizes the complexity of a model, is also called lasso regularization. The basic idea of regularization in a linear model is that parameters in a model can't be too large such that too many factors contribute to the predicted outcomes. However, lasso does one more thing. It not only penalizes the magnitude but also the parameters' existence. We will see how it works soon.

The name lasso comes from least absolute shrinkage and selection operator. It will shrink the values of parameters in a model. Because it uses the absolute value form, it also helps with selecting explanatory variables. We will see how it works soon.

Lasso regression is just like linear regression but instead of minimizing the sum of squared errors, it minimizes the following function. The index i loops over all data points where j loops over all coefficients:

Unlike standard...