This document provides an overview and introduction to R and R Studio. It outlines the objectives of understanding R as a programming language, installing R and R Studio, and an introduction to R as an object-oriented language. Instructions are provided on installing R for Windows and Mac as well as installing R Studio. An overview of the R Studio interface is given along with details on upgrading R to a specific version. The document concludes with information on R as an object-oriented language and creating and manipulating objects.

1. R BROWN-BAG SEMINAR 2.1
Topic: Introduction to R
Presenter: Faith Musili
F.Musili@cgiar.org
ICRAF-Geoscience Lab

2. OBJECTIVES
1. Understand R as a programming language.
2. Install R and R studio
3. Overview of R studio Panels
4. Introduction of R as an object oriented language

3. ABOUT R AND R STUDIO
R is a free software environment for statistical computing and
graphics. It’s open source and therefore available free of
charge.
R studio is a powerful and productive user interface for R. It's
free and open source, and works great on Windows, Mac, and
Linux.
R is an object oriented programming language where we
create objects and manipulate them as intended. Objects can be
Data frames, vectors, matrices, lists, raw data, spatial objects ,
maps etc.

4. WHY R LANGUAGE
 R is not just a statistics package, it’s a language(allows you to
specify the performance of new tasks without any limitations)
 R is designed to operate the way that problems are thought about
and has very simple syntax.
 R is both flexible and powerful.
 It is very interactive and thus suitable for data analysis.
• R syntax is very simple and intuitive. For instance,
n <- 10 + 2
n
[1] 12

5. INSTALL R FOR WINDOWS
Go to your browser and search for R 3.2.4 windows
Choose Download R-3.2.4 for Windows
Click, Download R 3.2.4 for windows (64 megabytes, 32/64
bit )
Then, save the file and run it after download is complete.
Click next in all the popups that appear then finish.
Open the installed r

6. INSTALL R FOR MAC
Go to your browser and search for R 3.2.4 mac
Choose R for Mac OS X
In the page that opens, click old in the second line
Scroll down the page and choose R-3.2.4.pkg
Then, save the file and run it after download is complete.
Click continue and then install
Open the installed r

7. INSTALL R STUDIO
 Open browser and search for r studio download
 Choose Download RStudio –RStudio
 Scroll down the page that opens and go to Installers
 Choose the download file according to your operating system
 Save the file and run it after download is complete.
 Click Next and then Finish
Open R studio

8. UPGRADING R TO A SPECIFIC VERSION
FOR MAC:
• Download and install the new version of R you need.
Go to /Library/frameworks/Rframeworks/versions/<old
version>/Resources/library and copy everything inside.
 Paste the above items inside
/Library/frameworks/Rframeworks/versions/<new
version>/Resources/library
• Restart R studio
• Write “update.packages()” on the console and execute

9. UPGRADING R TO A SPECIFIC VERSION
FOR Windows:
• Download and install the new version of R you need.
Go to LibrariesDocumentsRwin-library<old version>
and copy everything inside.
 Paste the above items inside
LibrariesDocumentsRwin-library<new
version>Restart R studio
• Write “update.packages()” on the console and execute

10. RSTUDIO
R SCRIPT
CONSOLE (Script
output panel)
File ,Plots, Package
installation and
Help panels
Data Objects

11. AS AN OBJECT ORIENTED LANGUAGE
• An object can be created with the “assign” operator which is written as an arrow with a minus sign and a
bracket; this symbol can be oriented left-to-right or the reverse:
n <- 15
n
[1] 15
5 -> n
n
[1] 5
x <- 1
X <- 10
x
[1] 1
X
[1] 10
• If the object already exists, its previous value is erased. The value assigned this way may be the result of an
operation and/or a function.
n<-3+sqrt(10)
n
[1] 6.162278

12. NEXT …............
Installation of packages
Importing different data into r
Data manipulation in R