Basic Operators in R

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 , and

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

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

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 changed to 20, 40 and 66, what will be the results?