How to Create, Access, and Modify Vector Elements in R ?

In this article, we are going to create, modify and access vector elements in the R Programming language. Vector is a one-dimensional data structure that holds multiple data type elements.

Creating a vector:

It can be done in these ways:

• Using c() function.
• Using : operator.
• Using seq() function.

Method 1: Using C() function.

The c() function in R Language is used to combine the arguments passed to it. We can create a vector by using c()

Syntax: c(value1,value2,……..,value n)

Where, c stands for combine, values are the input data to the vector.

Example 1: So in this program, we are going to create elements from 1 to 20 and display it

R

# create vector with range
# operator from 1 to 20 elements
vec = c(1:20)
print(vec)

Output:

Example 2: In this example, we are going to create a vector with different data type elements and display it.

Character type, float type, and int type are used. Int type data is created by using the range operator 

R

# create vector with different data type elements
vec=c( 1 : 20, "sravan", "deepika",
      "jyothika", 45.7, 56, 34, 56)
print(vec)

Output:

Method 2: Using : operator.

We can use : operator to creates the series of numbers in sequence for a vector. 

Code:

R

Data <- 1:20;
print(Data);

Output:

 [1]  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20

Method 3: Using seq() function.

seq() function is used to create a sequence of elements in a Vector. It takes the length and difference between values as optional argument. 

Syntax: seq(from, to, by, length.out)

Parameters:
from: Starting element of the sequence
to: Ending element of the sequence
by: Difference between the elements
length.out: Maximum length of the vector

Code:

R

# R Program to illustrate
# the use of seq() Function

# Creating vector using seq()
vec1 <- seq(1, 10, by = 2)

vec2 <- seq(1, 10, length.out = 7)

# Printing vectors
print(vec1)
print(vec2)

Output:

[1] 1 3 5 7 9
[1]  1.0  2.5  4.0  5.5  7.0  8.5 10.0

Modifying vector elements

We can modify the vector elements by using [] operator

Syntax: vec[index_value]=new_data

Where index_value is the element index location

Example 1: In this example, we are going to create a vector with 5 integer type elements and modifying the 1st and 2nd elements as 100 and 200

R

# create vector with 5 numbers
vec = c( 10, 20, 3, 4, 5)
print(vec)

# change 10 to 100
vec[1]=100

# change 20 to 200
vec[2] = 200
print(vec)

Output:

Example 2: R program to modify the entire vector at a time.

In this example, we are going to modify the elements from 1 to 20 with 1010 to 120 at a time. 

R

# create vector with 20  numbers
vec = c( 1 : 20)
print(vec)

# modify all elements at a
# time from (1 to 20 ) - (101 to 120)
vec[1:20] = 101 : 120
print(vec)

Output:

Access vector elements

We can access vector elements using the indexing operator – [] and Indexing starts from 1.

Syntax: vector_name[index_value]

Example 1: R program to display values in a vector

In this example, we are going to create the vector with elements from 100 to 200 using range operator and going to access the 1st, 12th and 13th elements.

R

# create vector with range of
# 100 -200  numbers
vec = c( 100 : 200 )

# display element 1
print(vec[1])

# display element 12
print(vec[12])

# display element 13
print(vec[13])

Output:

Example 2: Display all the elements in a vector

In this example, we created a vector with integer data type elements from 100 to 199, with range operator and display all

R

# create vector with range
# of 100 -200  numbers
vec = c( 100 : 200 )

# display all
print(vec[ 1 : 100 ])

Output: