Part 1 - R programming tutorial for beginner - R Tutorial Introduction.

1. R Programming
Sakthi Dasan Sekar
http://shakthydoss.com 1

2. Introduction to R
R is a programming language developed as an alternative for S
language at AT&T Bell Laboratories by Robert Gentleman and Ross
Ihaka.
Due to its underlying philosophy and design R is incredibly excel in
statistical computation and graphic visualization.
R is free, open source with a very high activity community members.
Available cross all platforms (Linux, Mac, Windows)
http://shakthydoss.com 2

3. Introduction to R
R is much more than just its core language. It has a worldwide
repository system, the Comprehensive R Archive Network (CRAN)
http://cran.r-project.org
As of 2011, there were more than 3,000 such packages hosted on CRAN
and numerous more on other sites
http://shakthydoss.com 3

4. Introduction to R
Cons of R Language
R has a steep learning curve.
Working with large datasets is limited by RAM size.
http://shakthydoss.com 4

5. Introduction to R
Who use R in their business
http://shakthydoss.com 5

6. Introduction to R
Understanding of R language
• R Statement or Commands can be separated by a semicolon (;) or a newline.
• Assignment operator in R is "<-" (although "=" also works).
• All characters after # are treated as comments.
• There is not multi line or block level Comments.
• $ (dollar) operator in R is an analogous to .(dot) operator in other languages.
Student$name
Student$age
http://shakthydoss.com 6

7. Introduction to R
Installing R
Installing from CRAN (Comprehensive R Network)
Website: http://cran.r-project.org/
R is actively being improved all the time, Make sure that you choose
recent version to install.
http://shakthydoss.com 7

8. Introduction to R
Installing R in windows
For Windows and Mac OS X, one can simply download a self-installing binary.
For Linux, installation varies.
For the Debian distribution (including Ubuntu), R system can be installed using the regular
package-management tools.
Since R is open source, one can also compile and install it using the source code.
http://shakthydoss.com 8

9. Introduction to R
Installing R in windows
Window R package can be downloaded from
https://cran.r-project.org/bin/windows/base/
Download R 3.X.X for Windows executable file (.exe)
http://shakthydoss.com 9

10. Introduction to R
Click Next in the Setup Wizard.
You can leave to setting to default.
http://shakthydoss.com 10

11. Introduction to R
Open R Console (Rgui from your desktop) R Console
http://shakthydoss.com 11

12. Introduction to R
IDE for R
The RStudio project currently provides most of the desired features for
an IDE in a novel way, making it easier and more productive to use R.
The RStudio program can be run on the desktop or through a web
browser.
The desktop version is available for Windows, Mac OS X, and Linux
platforms.
http://shakthydoss.com 12

13. Introduction to R
Notable IDEs for R
Name Platforms
ESS Windows, Mac, Linux
Eclipse Windows, Mac, Linux
SciViews Windows, Mac, Linux
JGR Windows, Mac, Linux
Tinn-R Windows
Notepad++ Windows
Rgui Windows
http://shakthydoss.com 13

14. Introduction to R
Installing RStudio is usually a straightforward process.
For Windows and Mac OS X, one can simply download a self-installing binary.
For Linux, installation varies.
For the Debian distribution (including Ubuntu), RStudio can be installed using
the regular package-management tools.
http://shakthydoss.com 14

15. Introduction to R
Installing RStudio in windows.
https://www.rstudio.com/products/rstudio/download/
Download Rstudio.
Run the installation file.
http://shakthydoss.com 15

16. Introduction to R
Open RStudio
Source Panel
R console
Environment
Panel
File/Package
Panel
http://shakthydoss.com 16

17. Introduction to R
R workspace
When R is started, it follows this process
R is started in the working directory (aka workspace).
If present, the .Rprofile file’s commands are executed.
If present, the .Rdata file is loaded.
http://shakthydoss.com 17

18. Introduction to R
R workspace
R stores user-defined objects in workspace.
At the end of an R session, the user can save an snapshot of the current
workspace and reloaded automatically next time when R is started.
getwd() - return working directory
setwd() - set working directory
http://shakthydoss.com 18

19. Introduction to R
In RStudio you can set the workspace by Tools -> Global Options
http://shakthydoss.com 19

20. Introduction to R
• There are over 1,000 functions at the core of R, and new R functions are created all of the time.
• Each R function comes with its own help page, which you can access by typing the function’s name after
question mark
Getting Help
help.start() # Load HTML help pages into browser
help(package) # List help page for "package"
?package # Shortform for "help(package)"
help.search("keyword") # Search help pages for "keyword"
?help # For more options
help(package=base) # List tasks in package "base"
http://shakthydoss.com 20

21. Introduction to R
Packages
• Many Data Scientist programmers and statisticians , use R to design tools that can help people analyze data. Many of these
people contribute their code as preassembled collections of functions and objects called packages.
• Each R package is hosted at http://cran.r-project.org
• Not all packages are loaded by default, but can be load / install on demand
library() # List available packages to load
library("package") # loads the package
library(help="package") # list package contents
detach("package:pkg") # Unload the loaded package "pkg"
install.packages(“package") # Install the package
http://shakthydoss.com 21

22. Introduction to R
Installing package by GUI RStudio -> Tools -> Install Packages
Check the package to load
http://shakthydoss.com 22

23. Introduction to R
Knowledge Check
http://shakthydoss.com 23

24. Introduction to R
Which of the statement is TRUE.
A. R is a propitiatory general purpose language
B. R excels in statically computation and graphic capabilities.
C. R syntax are very similar to assembly language.
D. R has no GUI
Answer B
http://shakthydoss.com 24

25. Introduction to R
Which of the statement is TRUE.
A. Working with large datasets is limited by RAM size.
B. R language is own by AT&T Bell Labs
C. R available only for Unix platfroms
D. R language is design for parallel programming and horizontally scalable systems.
Answer A
http://shakthydoss.com 25

26. Introduction to R
What is CRAN stands for
A. Comprehensive R Network
B. Computational R Network
C. Comprehensive R Archive Network
D. Computational R Archive Network
Answer C
http://shakthydoss.com 26

27. Introduction to R
Which not an IDE for R language
A. RStudio
B. RGUI
C. Tinn-R
D. Dreamweaver
Answer D
http://shakthydoss.com 27

28. Introduction to R
When R is started.
A. It loads .Rprofile and .Rdata from workspace
B. It attempts loads only .Rdata from workspace
C. It attempts loads only .Rprofile from workspace
D. Does nothing
Answer A
http://shakthydoss.com 28

29. Introduction to R
Function getwd() - return working directory
A. TRUE
B. FALSE
Answer A
http://shakthydoss.com 29

30. Introduction to R
Function setwd() - set working directory
A. TRUE
B. FALSE
Answer A
http://shakthydoss.com 30

31. Introduction to R
How to browser for all help documents in R
A. help.start()
B. help(help)
C. library()
D. install.packages(help)
Answer A
http://shakthydoss.com 31

32. Introduction to R
How to install new packages in R.
A. Install(“package”)
B. library(“package”)
C. install.packages("package")
D. load(“package”)
Answer C
http://shakthydoss.com 32

33. Introduction to R
How to load a installed package.
A. load("package")
B. library("package")
C. install.packages("package")
D. library()
Answer B
http://shakthydoss.com 33