R Vectors - Create, Access, Modify and Delete a Vector Elements in R

 A Vector in R is basically a set of values of the same basic data type like numeric character etc. A vector in R is created using the c() function that represents a combination of elements.

I have posted basics about R Vectors in the previous post, here we'll learn more about Vector data type.

Creating a Vector in R

In R even a single value is considered as a vector of length 1, We can create a multi-element R Vector using a colon (:) like this

1. #Creating a vector using a colon
2. v <- (1:10)
3. #Print its values
4. print(v)

and output is

1. [1] 1 2 3 4 5 6 7 8 9 10

Create a vector using c() function

1. # A Numeric Vector
2. numeric_vector <- c(10, 20, 30)
3. # A Character Vector
4. character_vector <- c("a", "b", "c")
5. # A Boolean Vector
6. boolean_vector <-c(TRUE,FALSE,TRUE)

now print these vectors

1. > #Print All Vectors
2. > print(numeric_vector)
3. [1] 10 20 30
4. > print(character_vector)
5. [1] "a" "b" "c"
6. > print(boolean_vector)
7. [1] TRUE FALSE TRUE

Accessing Vector Elements in R

Vectors in R works on the concept of the index and to access vector elements value we need to use the index, Indexing in R starts from 1 and here we'll see how to access a vector's value.

1. #Define a Vector
2. v <- c(10,20,30,40,50,60,70,80)
4. #Get element's value using index
5. a <- v[c(1,3,4,6)]
7. #Print values
8. print(a)

and output is

1. [1] 10 30 40 60

We can also use boolean values (TRUE, FALSE) to get elements of the vector, See an example here

1. #Define a Vector
2. v <- c(10,20,30,40,50,60,70,80)
4. #Get element's value using boolean value
5. a <- v[c(TRUE,FALSE,FALSE,FALSE,TRUE,TRUE,FALSE,TRUE)]
7. #Print values
8. print(a)

and output is

1. [1] 10 50 60 80

Using negative value as index removes that particular element from the result, see an example

1. #Define a Vector
2. v <- c(10,20,30,40,50,60,70,80)
4. #Get element's value using negative index
5. a <- v[c(-2,-4,-6,-8)]
7. #Print values
8. print(a)

and output is

1. [1] 10 30 50 70

Arithmetic Operation in Vectors

We can perform variables like arithmetic operations (Addition, Subtraction, Multiplication, Divison) in vectors too.

1. #Add two vectors
2. a <- c(1, 2, 3)
3. b <- c(4, 5, 6)
5. # Addition
6. c <- a+b
8. # Subtraction
9. d <- a-b
11. # Multiplication
12. e <- a*b
14. # Divison
15. f <- a/b

now on printing this

1. > #Print Values
2. > cat("Addition",c)
3. Addition 5 7 9>
4. > cat("Subtraction",d)
5. Subtraction -3 -3 -3>
6. > cat("Multiplication",e)
7. Multiplication 4 10 18>
8. > cat("Divison",f)
9. Divison 0.25 0.4 0.5>

Modifying a Vector in R

We can modify vector’s elements values using index and assignment operator. See this example

1. #Define a Vector
2. v <- c(10,20,30,40,50,60,70,80)
4. #Modify 3rd element value
5. v[3] <- 33;
7. #Print Updated Vector
8. print(v)

and output is

1. [1] 10 20 33 40 50 60 70 80

Deleting a Vector in R

We can delete a vector by setting a vector to NULL.

1. #Define a Vector
2. v <- c(10,20,30,40,50,60,70,80)
4. #Set its value to NULL
5. v <- NULL
7. #Print Vector
8. print(v)

Cheers 🙂 Happy Learning

 Loops (R Loops) are used to repeat the execution of a block of statements based on some predefined conditions. In R Programming we have the following types of loops that can be used as per development requirements.

Repeat Loop in R Programming

Repeat loop in R executes the set of statements until the defined condition is satisfied

1. #Print some value using Repeat Loop
2. count <- 1
4. repeat {
5. print("R Programming")
6. count <- count+1
8. if(count > 5) {
9. break
10. }
11. }

and output is

1. [1] "R Programming"
2. [1] "R Programming"
3. [1] "R Programming"
4. [1] "R Programming"
5. [1] "R Programming"

Another Example

1. #Print table of 10 using Repeat Loop
2. a <- 10
3. count <- 1
5. repeat {
6. print(a*count)
7. count <- count+1
9. if(count > 10) {
10. break
11. }
12. }

and output is

1. [1] 10
2. [1] 20
3. [1] 30
4. [1] 40
5. [1] 50
6. [1] 60
7. [1] 70
8. [1] 80
9. [1] 90
10. [1] 100

While Loop in R Programming

While loop checks the condition before starting loop execution and executes the set of statements while the defined condition is true.

1. #Declare and Initialise a varable
2. a <- 1
4. #Check condition in a while loop
5. while(a<=5){
6. print(a)
7. a <- a+1
8. }

and output is

1. [1] 1
2. [1] 2
3. [1] 3
4. [1] 4
5. [1] 5

FOR Loop in R Programming

When you need to execute a code a specific number of times then FOR loop comes into action. Here we'll see how to iterate a vector using FOR loop.

1. #Declare and Initialise a Vector
2. a <- c(10,TRUE,"Ashish",2.4)
4. #Iterate vector using FOR loop
5. for(i in a){
6. print(i)
7. }

and output is

1. [1] "10"
2. [1] "TRUE"
3. [1] "Ashish"
4. [1] "2.4"

Cheers 🙂 Happy Learning