Basic Operators in R

Zulquar Nain
AMU

February 15, 2024

Lets learn 4m History

• Open R Studio using R project(created before)

• Create a R script file

• save it(Use lecture number or date as name)

• Do make comments in your script file

• In the r script file/console, calculate \(21+21\) , \(7*6\) and \((0.3/4) × \sqrt(31360)\)

Solutions

The Code

21+21

[1] 42

The Code

7*6

[1] 42

The Code

.3/4*sqrt(31360)

[1] 13.28157

Basic Operators

• Basic Operators can be classified into four categories
  • Arithmetic Operators
  • Relational Operators
  • Logical Operators
  • Assignment Operators

Assignment Operator

• These operators are used to assign values to variables

• The operators <-and = can be used most of the time interchangeably

• The <<- operator is used for assigning to variables in the parent environments (more like global assignments)

• right ward operators, however rarely used
  

Table: Assignment Operators

Operator	Descriptor
<-, <<-, =	Leftward Assignemnt
->, ->>	Rightward Assignment

Assignment Operator

Example

##| code-line-numbers: "1|3|4"

x <- 5
x

[1] 5

y = 9
y

[1] 9

10 -> b
b

[1] 10

M <<- 50
50 ->> N
M > N

[1] FALSE

msg <- "Hey, YOU people are SMART! & I mean it"
msg

[1] "Hey, YOU people are SMART! & I mean it"

Arithmetic Operators

Table 2: Arithmatic Operators

Operators	Description
+	Addition
-	Subtraction
*	Multiplication
/	Division
^	Exponential
%%	Modulus(Remainder Division)

Arithmetic Operator

Example

##| code-line-numbers: "1|3|4"

X <- 5 # this is assignment operator, we discussed earlier
Y <- 16 # we have values of X and Y

X+Y

[1] 21

X-Y

[1] -11

X*Y

[1] 80

Y/X

[1] 3.2

Y%%X

[1] 1

Y^X

[1] 1048576

2^3

[1] 8

Relational Operators

• Relational operators are used to compare between values
  

  Table 3: Relational Operator

  Operators	Description
  <	Less than
  >	Greater than
  <=	Less than or equal to
  >=	Greater than or equal to
  ==	Equal to
  !=	Not equal to

Relational Operators

Examples

##| code-line-numbers: "1|3|4"

X <- 5 # this is assignment operator, we discussed earlier
Y <- 16 # we have values of X and Y
X<Y

[1] TRUE

X>Y

[1] FALSE

X<=5

[1] TRUE

Y>20

[1] FALSE

Y==16

[1] TRUE

Y!=X

[1] TRUE

Logical Operators

• Logical operators are used to carry out Boolean operations like AND, OR etc

• Operators & and | perform element-wise operation producing result having length of the longer operand

• But && and || examines only the first element of the operands resulting into a single length logical vector

• Zero is considered FALSE and non-zero numbers are taken as TRUE

Logical Operators

Logical operators

• &&→(logical AND)

• Compares two expressions and returns true if both evaluate to true.

• Returns false only if both expressions are false.

  • true && false → Evaluates false because the second is false

  • false && true → Evaluates false because the first is false

  • true && true → Evaluates true because both are true

  • false && false → Evaluates false because both are false
    

Logical Operators-Explanations

• ||→(logical OR)

• Compares two expressions and returns true if one or both evaluate to true.

• Returns false only if both expressions are false.

  • true || false → Evaluates true because the first is true

  • false || true → Evaluates true because the second is true

  • true || true → Evaluates true because both are true

  • false || false → Evaluates false because both are false
    

Logical Operators-Examples

##| code-line-numbers: "1|2|3|4|5|6|7"

X <- c(TRUE, FALSE, 0,6)
Y <- c(FALSE,TRUE,FALSE,TRUE)
!X

[1] FALSE  TRUE  TRUE FALSE

X&Y

[1] FALSE FALSE FALSE  TRUE

X|Y

[1]  TRUE  TRUE FALSE  TRUE

a <- c(TRUE)
b <- c(FALSE)
a&&b

[1] FALSE

a||b

[1] TRUE

Explore!

age <- 16
if (!(age > 18)) {
  print("You are Too Young")
} else if(age > 18 && age <= 35) {
  print("Young Guy")
} else if(age == 36 || age <= 60) {
  print("You are Middle Age Person")
} else {
  print("You are too Old")
}

[1] "You are Too Young"

Some more basic operators

Your TURN

• Add, subtract, multiply and divide your age with your friend’s age
• Use logical operators to compare your age with your friend’s age
• If the value of x in the last example is changeded to 20, 40 and 66, what will be the results?

Have patience