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

Using SQL to query data frames via the sqldf package


In the previous chapter, you learned how to compose SQL statements to query data from relational databases such as SQLite and MySQL. Is there a way to directly use SQL to query data frames in R as if these data frames are tables in relational databases? The sqldf package says yes.

This package takes advantage of SQLite, thanks to its lightweight structure and easiness to embed into an R session. Run the following command to install this package if you don't have it:

install.packages("sqldf") 

First, let's attach the package, as shown in the following code:

library(sqldf) 
## Loading required package: gsubfn 
## Loading required package: proto 
## Loading required package: RSQLite 
## Loading required package: DBI 

Note that when we attach sqldf, a number of other packages are automatically loaded. The sqldf package depends on these packages, because what it does is basically transferring data and converting data...