## Data Structure: Vector

## ↪ Creating Vector

A vector in R can contain any number of elements, but all of the elements must be of the same type – that is a vector cannot contain a mix of numbers, logical, and character types.

The c() function is used for creating the Vector. “=” or “->” can be used as an assignment operator.

x = c(5,8,10,12) x

---Output--- [1] 5 8 10 12

The vector can also be given a name using the <- operator, much like the = assignment operator.

x <- c("A","B","X","Z") x

—Output— [1] “A” “B” “X” “Z”

The typeof() function is used for finding the data type present in the vector.

typeof(x)

---Output--- [1] "double"

By default, a number is considered double in R. To create an integer Vector, append the number by L.

x = c(5L,8L,10L,12L) typeof(x)

---Output--- [1] "integer"

#### Data Structure: Vector

## ↪ Vector of Sequence

The ':' operator is used for creating a sequence with the vector function c().

x = c(1:15) x

---Output--- [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

A sequence can be created simply by

x = 1:15 x

The seq() function is used for creating a sequence.

x = seq(1,15) x

Sequence with increment value.

x = seq(1,15,3) x

---Output--- [1] 1 4 7 10 13

Another example of sequence with fraction incremental value.

x = seq(0,1,0.1) x

---Output--- [1] 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

#### Data Structure: Vector

## ↪ Accessing an element in the vector

Accessing an element using an index.

x[3]

Accessing range of elements in the vector.

x[5:8]

Exclude an item

x = c(10,20,30,40) x[-3]

---Output--- [1] 10 20 40

A logical vector can be used to indicate whether an item should be included.

x[c(TRUE,FALSE,FALSE,TRUE)]

---Output--- [1] 10 40

#### Data Structure: Vector

## ↪ Arithmetic Operations

Arithmetic operations can be performed when the two vectors are of same length.

x = c(10,20,30,40) y = c(20,30,40,50) x + y # Prints [1] 30 50 70 90 y-x # Prints [1] 10 10 10 10 x*y # Prints [1] 200 600 1200 2000 y/x # Prints [1] 2.000000 1.500000 1.333333 1.250000

Other singular arithmetic operations on Vector are possible.

x^2 # Prints [1] 100 400 900 1600 sqrt(x) # Prints [1] 3.162278 4.472136 5.477226 6.324555