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)

The general ARIMA model

Time series analysis deals with several models, but ARIMA models are the most used ones. ARIMA means autoregressive integrated moving average. That implies that the model relies on two mathematical artefacts (autoregressive (AR) and moving-average (MA) processes) to model temporal phenomena. ARIMA is, thus, deeply rooted in stochastic processes, and what we will do is find a reasonable stochastic process (a combination of AR and MA processes) that matches the empirical autocovariance structure that we see in the data. AR processes are structured as Yt = c1 Yt-1 + … + ck Yt-k + et, where et is Gaussian noise. On the other hand, MA processes are structured as Yt = c1 et-1 +…+ck et-k + et.

AR, MA and ARMA processes have a distinct autocorrelation structure. On the other hand, we will observe an autocorrelation structure for our data. In consequence...