Book Image

R Statistics Cookbook

By : Francisco Juretig
2 (2)
Book Image

R Statistics Cookbook

2 (2)
By: Francisco Juretig

Overview of this book

R is a popular programming language for developing statistical software. This book will be a useful guide to solving common and not-so-common challenges in statistics. With this book, you'll be equipped to confidently perform essential statistical procedures across your organization with the help of cutting-edge statistical tools. You'll start by implementing data modeling, data analysis, and machine learning to solve real-world problems. You'll then understand how to work with nonparametric methods, mixed effects models, and hidden Markov models. This book contains recipes that will guide you in performing univariate and multivariate hypothesis tests, several regression techniques, and using robust techniques to minimize the impact of outliers in data.You'll also learn how to use the caret package for performing machine learning in R. Furthermore, this book will help you understand how to interpret charts and plots to get insights for better decision making. By the end of this book, you will be able to apply your skills to statistical computations using R 3.5. You will also become well-versed with a wide array of statistical techniques in R that are extensively used in the data science industry.
Table of Contents (12 chapters)

LOESS regression

When we have a scatterplot between two variables Y, X we usually want to present a curve that relates the two variables. Firstly, because it allows us to see if the relationship is linear (or almost linear); secondly, because interpreting scatterplots is sometimes hard; and, finally, because we might want to have a simple model that can be used to predict Y in terms of X capturing all possible nonlinear patterns.

Locally Estimated Scatterplot Smoothing (LOESS) regression works by fitting lots of local models around each point. These local models are then averaged out. In particular, each model (fitted around a point X0,Y0) is fitted using weighted least squares (each point is weighted by how close the regressors are to the point X0). There is a parameter specified by the user, called the bandwidth, which specifies how much data is used in each one of these regressions...