Introduction to R and RStudio IDE

Wan Nor Arifin

Unit of Biostatistics and Research Methodology, Universiti Sains Malaysia.

Email: wnarifin@usm.my

February 13, 2019

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1 Why use R?

2 R and RStudio

3 R script

4 Function and Object

5 R packages

6 Working directory

7 Help

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Why use R?

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R

R is a free software environment for statisticalcomputing and graphics. It compiles and runs on a widevariety of UNIX platforms, Windows and MacOS.

Source: https://www.r-project.org/

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R outpaces other statistics software

Figure 1: R popularity

Source: http://r4stats.com/articles/popularity/Wan Nor Arifin (USM) Introduction to R and RStudio IDE February 13, 2019 5 / 27

R is getting more popular among academician

Figure 2: Impressive growth of R

Source: https://stackoverflow.blog/2017/10/10/impressive-growth-r/Wan Nor Arifin (USM) Introduction to R and RStudio IDE February 13, 2019 6 / 27

Availability of R packages

Figure 3: CRAN

Source: https://cloud.r-project.org/web/packages/index.html, as of 11/2/2019.Wan Nor Arifin (USM) Introduction to R and RStudio IDE February 13, 2019 7 / 27

R and RStudio

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R InstallationR @ https://cran.r-project.org/

Figure 4: R Project

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RStudio InstallationRStudio @ http://www.rstudio.com/

Figure 5: RStudio

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R to PDF Installation

Windows & MacOS – MikTeX @ https://miktex.org/downloadLinux – texlive.

Important for R-markdown session later.

Figure 6: MiKTeXWan Nor Arifin (USM) Introduction to R and RStudio IDE February 13, 2019 11 / 27

R Interface

Figure 7: Plain R

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RStudio Interface

Figure 8: RStudio

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R script

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Script panel

File > New file > R script

type all commands/functions herecomments, start with “#”run all commands by Ctrl+Enter

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Function and Object

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Function

R function(), think of MS Excel functionstructure

function(argument1 = value, argument2 = value)

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Object

name assigned on left side of “<-” / “=”variable, data (data frame, matrix, list)

x <- 1y = 2z = x + yz # type object name, you'll get the value

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R packages

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Install packages a.k.a libraries

Graphically

Packages > Install

Command

e.g. psych, car

install.packages("psych")install.packages("car")

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Load libraries

e.g. load psych and car,

library(psych)library(car)

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Working directory

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Set working directory

1 Browse to target directory: Files Tab > . . . > Go To Folder2 Files Tab > More > Set As Working Directory

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Help

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Help

If you know the name of packages/functions,

?psych?library

Search by keywords,

??mean??survey

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Thank you

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References

Fox, J., Weisberg, S., & Price, B. (2018). Car: Companion to appliedregression. Retrieved from https://CRAN.R-project.org/package=car

R Core Team. (2018). R: A language and environment for statisticalcomputing. Vienna, Austria: R Foundation for Statistical Computing.Retrieved from https://www.R-project.org/

Revelle, W. (2018). Psych: Procedures for psychological, psychometric, andpersonality research. Retrieved fromhttps://CRAN.R-project.org/package=psych

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