Book Image

Learning R Programming

By : Kun Ren
Book Image

Learning R Programming

By: Kun Ren

Overview of this book

R is a high-level functional language and one of the must-know tools for data science and statistics. Powerful but complex, R can be challenging for beginners and those unfamiliar with its unique behaviors. Learning R Programming is the solution - an easy and practical way to learn R and develop a broad and consistent understanding of the language. Through hands-on examples you'll discover powerful R tools, and R best practices that will give you a deeper understanding of working with data. You'll get to grips with R's data structures and data processing techniques, as well as the most popular R packages to boost your productivity from the offset. Start with the basics of R, then dive deep into the programming techniques and paradigms to make your R code excel. Advance quickly to a deeper understanding of R's behavior as you learn common tasks including data analysis, databases, web scraping, high performance computing, and writing documents. By the end of the book, you'll be a confident R programmer adept at solving problems with the right techniques.
Table of Contents (21 chapters)
Learning R Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

Applying numeric methods


In the previous sections, you learned about a number of functions that range from inspecting data structures to math and logical operations. These functions are fundamental to solving problems such as root finding and doing calculus. As a computing environment, R already implements various tools of good performance so that users do not have to reinvent the wheel. In the following sections, you will learn the built-in functions designed for root finding and calculus.

Root finding

Root finding is a commonly encountered task. Suppose we want to find the roots of the following equation:

x2 + x - 2= 0

To manually find the roots, we can transform the preceding equation in product terms:

(x+2)(x-1)= 0

Therefore, the roots of the equation are x1= -2 and x2= 1.

In R, polyroot() can find roots of a polynomial equation in the form of:

For the preceding problem, we need to specify the polynomial coefficient vector from zero order to the term of the highest order present in the equation...