Learning R

Session 1: Foundations of R Programming

Part A: Getting Started with R

Welcome to R!

R is a powerful programming language for:

Statistical computing
Data analysis
Data visualization
Machine learning

Let’s install R!

For downloading R: https://cran.r-project.org/mirrors.html

Let’s install R Studio!

For downloading R Studio: https://posit.co/products/open-source/rstudio/

RStudio Interface

Script Editor (top-left)
Console (bottom-left)
Environment (top-right)
Files/Plots/Help (bottom-right)
See this video for a how to: R Studio

Creating Your First Project

File → New Project
Choose Directory Location
Name Your Project
Click “Create Project”

Tip

See this video for a how to: R Studio Project

Projects help organize your work and make it reproducible!

Data Types

Let’s understand data types:

Numeric

x <- 42
class(x)

[1] "numeric"

Character

name <- "UAE"
class(name)

[1] "character"

Logical

is_fun <- TRUE
class(is_fun)

[1] "logical"

🔨 Practice Time!

Try these exercises in your console:

Create a numeric variable called Time_to_travel_home with the time you spend travelling
Create a character variable Where_do_I_work
Create a logical variable Learning_impact_evaluation
Use class() to check their types

🔨 Results

Time_to_travel_home <- 
Where_do_I_work <- 
Learning_impact_evaluation <-

Warning

Watch out for this common mistakes!

Time to travel home <- 45

Where do I work == ADEO 

Learning-impact-evaluation <- TRUE

Part B: Working with Data

Vectors in R

Vectors are one-dimensional arrays:

# Creating vectors
numbers <- c(1, 2, 3, 4, 5)

gulf_countries <- c("UAE", "Saudi Arabia", "Oman")

logical_values <- c(TRUE, FALSE, TRUE)

Important

Try this vector operations!

numbers + 2

numbers * 2

gulf_countries  * 2

🔨 Practice Time: Vectors

Create these vectors and perform operations:

# Create a vector of 5 numbers
numbers <- 

# Create a vector of 3 cities in UAE
cities <- 

# Multiple your vector with numbers by 10

Built-in Functions (1)

R has many useful built-in functions:

# Statistical functions
numbers <- c(1, 2, 3, 4, 5)
mean(numbers)

[1] 3

sum(numbers)

[1] 15

max(numbers)

[1] 5

min(numbers)

[1] 1

Built-in Functions (2)

# Character functions
text <- "United Arab Emirates"
toupper(text)

[1] "UNITED ARAB EMIRATES"

nchar(text)

[1] 20

Getting Help in R

Three ways to get help:

Use ? before function name:

?mean

Use help():

help(sum)

Use examples:

example(max)

Installing Packages

Packages extend R’s functionality:

# Install a package
install.packages("tidyverse")

# Load a package
library(tidyverse)

Warning

Run install.packages() once per computer Run library() in each new session

Part C: Working with Data Frames

Creating Data Frames

Data frames are 2-dimensional data structures:

# Create a simple data frame
df <- data.frame(
  emirate = c("Abu Dhabi", "Dubai", "Ajman", "Fujairah","Sharjah","Ras Al Khaimah","Umm Al Quwain"),
  area = c(67340,259,4114,1450,1684,2590,720),
  international_airport = c(TRUE, TRUE, FALSE, TRUE, TRUE, FALSE, FALSE)
)

Let’s see the dataframe:

# View the data frame
df

         emirate  area international_airport
1      Abu Dhabi 67340                  TRUE
2          Dubai   259                  TRUE
3          Ajman  4114                 FALSE
4       Fujairah  1450                  TRUE
5        Sharjah  1684                  TRUE
6 Ras Al Khaimah  2590                 FALSE
7  Umm Al Quwain   720                 FALSE

Reading Data into R

If we want to import real data:

# Read CSV file

data <- read.csv("your_file.csv")

# Read tab-delimited file
data <- read.table("your_file.txt", 
                   header = TRUE, 
                   sep = "\t")

# Read excel file
library(readxl)
data <- read_excel("your_file.xlsx")

🔨 Practice Time: Reading Data

Download and read the iris dataset:

# Built-in dataset
data(iris)

variable.names(iris)

[1] "Sepal.Length" "Sepal.Width"  "Petal.Length" "Petal.Width"  "Species"

iris

    Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
1            5.1         3.5          1.4         0.2     setosa
2            4.9         3.0          1.4         0.2     setosa
3            4.7         3.2          1.3         0.2     setosa
4            4.6         3.1          1.5         0.2     setosa
5            5.0         3.6          1.4         0.2     setosa
6            5.4         3.9          1.7         0.4     setosa
7            4.6         3.4          1.4         0.3     setosa
8            5.0         3.4          1.5         0.2     setosa
9            4.4         2.9          1.4         0.2     setosa
10           4.9         3.1          1.5         0.1     setosa
11           5.4         3.7          1.5         0.2     setosa
12           4.8         3.4          1.6         0.2     setosa
13           4.8         3.0          1.4         0.1     setosa
14           4.3         3.0          1.1         0.1     setosa
15           5.8         4.0          1.2         0.2     setosa
16           5.7         4.4          1.5         0.4     setosa
17           5.4         3.9          1.3         0.4     setosa
18           5.1         3.5          1.4         0.3     setosa
19           5.7         3.8          1.7         0.3     setosa
20           5.1         3.8          1.5         0.3     setosa
21           5.4         3.4          1.7         0.2     setosa
22           5.1         3.7          1.5         0.4     setosa
23           4.6         3.6          1.0         0.2     setosa
24           5.1         3.3          1.7         0.5     setosa
25           4.8         3.4          1.9         0.2     setosa
26           5.0         3.0          1.6         0.2     setosa
27           5.0         3.4          1.6         0.4     setosa
28           5.2         3.5          1.5         0.2     setosa
29           5.2         3.4          1.4         0.2     setosa
30           4.7         3.2          1.6         0.2     setosa
31           4.8         3.1          1.6         0.2     setosa
32           5.4         3.4          1.5         0.4     setosa
33           5.2         4.1          1.5         0.1     setosa
34           5.5         4.2          1.4         0.2     setosa
35           4.9         3.1          1.5         0.2     setosa
36           5.0         3.2          1.2         0.2     setosa
37           5.5         3.5          1.3         0.2     setosa
38           4.9         3.6          1.4         0.1     setosa
39           4.4         3.0          1.3         0.2     setosa
40           5.1         3.4          1.5         0.2     setosa
41           5.0         3.5          1.3         0.3     setosa
42           4.5         2.3          1.3         0.3     setosa
43           4.4         3.2          1.3         0.2     setosa
44           5.0         3.5          1.6         0.6     setosa
45           5.1         3.8          1.9         0.4     setosa
46           4.8         3.0          1.4         0.3     setosa
47           5.1         3.8          1.6         0.2     setosa
48           4.6         3.2          1.4         0.2     setosa
49           5.3         3.7          1.5         0.2     setosa
50           5.0         3.3          1.4         0.2     setosa
51           7.0         3.2          4.7         1.4 versicolor
52           6.4         3.2          4.5         1.5 versicolor
53           6.9         3.1          4.9         1.5 versicolor
54           5.5         2.3          4.0         1.3 versicolor
55           6.5         2.8          4.6         1.5 versicolor
56           5.7         2.8          4.5         1.3 versicolor
57           6.3         3.3          4.7         1.6 versicolor
58           4.9         2.4          3.3         1.0 versicolor
59           6.6         2.9          4.6         1.3 versicolor
60           5.2         2.7          3.9         1.4 versicolor
61           5.0         2.0          3.5         1.0 versicolor
62           5.9         3.0          4.2         1.5 versicolor
63           6.0         2.2          4.0         1.0 versicolor
64           6.1         2.9          4.7         1.4 versicolor
65           5.6         2.9          3.6         1.3 versicolor
66           6.7         3.1          4.4         1.4 versicolor
67           5.6         3.0          4.5         1.5 versicolor
68           5.8         2.7          4.1         1.0 versicolor
69           6.2         2.2          4.5         1.5 versicolor
70           5.6         2.5          3.9         1.1 versicolor
71           5.9         3.2          4.8         1.8 versicolor
72           6.1         2.8          4.0         1.3 versicolor
73           6.3         2.5          4.9         1.5 versicolor
74           6.1         2.8          4.7         1.2 versicolor
75           6.4         2.9          4.3         1.3 versicolor
76           6.6         3.0          4.4         1.4 versicolor
77           6.8         2.8          4.8         1.4 versicolor
78           6.7         3.0          5.0         1.7 versicolor
79           6.0         2.9          4.5         1.5 versicolor
80           5.7         2.6          3.5         1.0 versicolor
81           5.5         2.4          3.8         1.1 versicolor
82           5.5         2.4          3.7         1.0 versicolor
83           5.8         2.7          3.9         1.2 versicolor
84           6.0         2.7          5.1         1.6 versicolor
85           5.4         3.0          4.5         1.5 versicolor
86           6.0         3.4          4.5         1.6 versicolor
87           6.7         3.1          4.7         1.5 versicolor
88           6.3         2.3          4.4         1.3 versicolor
89           5.6         3.0          4.1         1.3 versicolor
90           5.5         2.5          4.0         1.3 versicolor
91           5.5         2.6          4.4         1.2 versicolor
92           6.1         3.0          4.6         1.4 versicolor
93           5.8         2.6          4.0         1.2 versicolor
94           5.0         2.3          3.3         1.0 versicolor
95           5.6         2.7          4.2         1.3 versicolor
96           5.7         3.0          4.2         1.2 versicolor
97           5.7         2.9          4.2         1.3 versicolor
98           6.2         2.9          4.3         1.3 versicolor
99           5.1         2.5          3.0         1.1 versicolor
100          5.7         2.8          4.1         1.3 versicolor
101          6.3         3.3          6.0         2.5  virginica
102          5.8         2.7          5.1         1.9  virginica
103          7.1         3.0          5.9         2.1  virginica
104          6.3         2.9          5.6         1.8  virginica
105          6.5         3.0          5.8         2.2  virginica
106          7.6         3.0          6.6         2.1  virginica
107          4.9         2.5          4.5         1.7  virginica
108          7.3         2.9          6.3         1.8  virginica
109          6.7         2.5          5.8         1.8  virginica
110          7.2         3.6          6.1         2.5  virginica
111          6.5         3.2          5.1         2.0  virginica
112          6.4         2.7          5.3         1.9  virginica
113          6.8         3.0          5.5         2.1  virginica
114          5.7         2.5          5.0         2.0  virginica
115          5.8         2.8          5.1         2.4  virginica
116          6.4         3.2          5.3         2.3  virginica
117          6.5         3.0          5.5         1.8  virginica
118          7.7         3.8          6.7         2.2  virginica
119          7.7         2.6          6.9         2.3  virginica
120          6.0         2.2          5.0         1.5  virginica
121          6.9         3.2          5.7         2.3  virginica
122          5.6         2.8          4.9         2.0  virginica
123          7.7         2.8          6.7         2.0  virginica
124          6.3         2.7          4.9         1.8  virginica
125          6.7         3.3          5.7         2.1  virginica
126          7.2         3.2          6.0         1.8  virginica
127          6.2         2.8          4.8         1.8  virginica
128          6.1         3.0          4.9         1.8  virginica
129          6.4         2.8          5.6         2.1  virginica
130          7.2         3.0          5.8         1.6  virginica
131          7.4         2.8          6.1         1.9  virginica
132          7.9         3.8          6.4         2.0  virginica
133          6.4         2.8          5.6         2.2  virginica
134          6.3         2.8          5.1         1.5  virginica
135          6.1         2.6          5.6         1.4  virginica
136          7.7         3.0          6.1         2.3  virginica
137          6.3         3.4          5.6         2.4  virginica
138          6.4         3.1          5.5         1.8  virginica
139          6.0         3.0          4.8         1.8  virginica
140          6.9         3.1          5.4         2.1  virginica
141          6.7         3.1          5.6         2.4  virginica
142          6.9         3.1          5.1         2.3  virginica
143          5.8         2.7          5.1         1.9  virginica
144          6.8         3.2          5.9         2.3  virginica
145          6.7         3.3          5.7         2.5  virginica
146          6.7         3.0          5.2         2.3  virginica
147          6.3         2.5          5.0         1.9  virginica
148          6.5         3.0          5.2         2.0  virginica
149          6.2         3.4          5.4         2.3  virginica
150          5.9         3.0          5.1         1.8  virginica

Basic Data Inspection (1)

# First few rows
head(iris)

  Sepal.Length Sepal.Width Petal.Length Petal.Width Species
1          5.1         3.5          1.4         0.2  setosa
2          4.9         3.0          1.4         0.2  setosa
3          4.7         3.2          1.3         0.2  setosa
4          4.6         3.1          1.5         0.2  setosa
5          5.0         3.6          1.4         0.2  setosa
6          5.4         3.9          1.7         0.4  setosa

# Last few rows
tail(iris)

    Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
145          6.7         3.3          5.7         2.5 virginica
146          6.7         3.0          5.2         2.3 virginica
147          6.3         2.5          5.0         1.9 virginica
148          6.5         3.0          5.2         2.0 virginica
149          6.2         3.4          5.4         2.3 virginica
150          5.9         3.0          5.1         1.8 virginica

Basic Data Inspection (2)

Essential functions for data exploration:

# Structure of the data
str(iris)

'data.frame':   150 obs. of  5 variables:
 $ Sepal.Length: num  5.1 4.9 4.7 4.6 5 5.4 4.6 5 4.4 4.9 ...
 $ Sepal.Width : num  3.5 3 3.2 3.1 3.6 3.9 3.4 3.4 2.9 3.1 ...
 $ Petal.Length: num  1.4 1.4 1.3 1.5 1.4 1.7 1.4 1.5 1.4 1.5 ...
 $ Petal.Width : num  0.2 0.2 0.2 0.2 0.2 0.4 0.3 0.2 0.2 0.1 ...
 $ Species     : Factor w/ 3 levels "setosa","versicolor",..: 1 1 1 1 1 1 1 1 1 1 ...

# Statistical summary
summary(iris)

  Sepal.Length    Sepal.Width     Petal.Length    Petal.Width   
 Min.   :4.300   Min.   :2.000   Min.   :1.000   Min.   :0.100  
 1st Qu.:5.100   1st Qu.:2.800   1st Qu.:1.600   1st Qu.:0.300  
 Median :5.800   Median :3.000   Median :4.350   Median :1.300  
 Mean   :5.843   Mean   :3.057   Mean   :3.758   Mean   :1.199  
 3rd Qu.:6.400   3rd Qu.:3.300   3rd Qu.:5.100   3rd Qu.:1.800  
 Max.   :7.900   Max.   :4.400   Max.   :6.900   Max.   :2.500  
       Species  
 setosa    :50  
 versicolor:50  
 virginica :50

Creating columns

iris$sepal.area <- iris$Sepal.Length *  iris$Sepal.Width

mean(iris$sepal.area)

[1] 17.82287

Final Exercise

Create a complete analysis:

Create a new script file
Load the mtcars dataset
Calculate mean of the first 3 numeric columns
Create a new column for computing hp / hp

# Your code here!
data(mtcars)

head(mtcars)
# Calculate means
# ...

# Create new column
# ...

Thank You!

Resources for Learning More

Exercise Solutions

Will be posted after class!

Tip

Remember: Practice is key to learning R!