R Vector

The Vector is the most basic Data structure in R programming. R Vector can hold a collection of similar types of elements (type may be an integer, double, char, Boolean, etc.) If you type different data types in a single R vector, then all the elements will be converted to a single type. In this article, we show how to Create a Vector, How to Access and manipulate the Vector Elements, Performing Arithmetic Operations on vectors in R.

Create a Vector in R

Every variable will be internally converted to Vector in R programming. In this example, we will create a vector in R of a single element. The most basic way to create a Vector is.

# Vector with 1 integer Element
print(10L)

# Vector with 1 String element
print("Hello")
R Vector 1

Create R Vector using Range

In R programming, there is a special operator called Range or Colon, and this will help to create a vector. For example, i <- 1:10 means 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

# Vector with Range
i <- 1:10
print(i)

# Vector with Decimal Range
j <- 1.5:5.5
print(j)

# Vector with Decimal Range
k <- 1.5:5.5
print(k)

# Vector with Decimal Range
n <- -10:-20
print(n)

# Letter Vector with Range
l <- LETTERS[1:6]
print(l)
R Vector 2

Create R Vector using Sequence (seq) Operator

Here, we create a vector in R programming using a sequence operator or simply a seq operator. The Sequence operator will return values sequentially.

# Vector with Sequence
a <- seq(from = 1, to = 10, by = 1) 
print(a)

# Here, from =, to =, by = values are option so you can remove them too
b <- seq(11, to = 15, by = 1) # Removing from
print(b)

c <- seq(15, 25, by = 3) # Removing both from, to
print(c)

d <- seq(2, 20, 2) # removing from, to, and by
print(d)

It will create a Vector in R starting with Value 1 at index position 1 and ends with Value 10 at index position 10 by increment the value by 1. It means 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

a <- seq(from = 1, to = 10, by = 1)
R Vector 3

Creating R Vector using concatenation c

This example create an R vector using c, or we say concatenation. It is the most popular R Programming approach, and normally we prefer this way.

# Vector with Concatenation

# Numeric Vector
a <- c(1, 2, 3, 4) 
print(a)

# Character vector
b <- c("India", "China", "Japan", "Russia", "Sri Lanka") 
print(b)

#Boolean vector
d <- c(TRUE, FALSE, FALSE, TRUE, TRUE) 
print(d)

# Mixed Vector and its Type will be Character
e <- c("India", 2, "China", 1, TRUE) 
print(e)
typeof(e) # this will return the Data type of Vector e

# Placing or Nesting One Vector inside the another
f <- c("UK", "USA", TRUE, FALSE, b) # b is another Vector
print(f)
R Vector 4

Access R Vector Elements

In R programming, We can use the index position to access the elements in a Vector. Using this index value, we can access or alter/change each and every individual element present in the vector. Index value starts at 1 and ends at n where n is the vector length.

For example, if we declare a vector that stores 10 elements then index starts at 1 and ends at 10. To access or alter 1st value use Vector_Name[1] and to alter or access the 10th value, use Vector_Name[10].

# R Vector Elements Accessing
a <-  c("India", "China", "Japan", "UK", "USA", "Russia", "Sri Lanka") 
print(a)

print(a[1])
print(a[3])

print(a[1:3])
print(a[4:6])
R Vector 5

We declared a Vector called a and assigned the following values

a <-  c("India", "China", "Japan", "UK", "USA", "Russia", "Sri Lanka")

Here, a[1] means element at first position (i.e., India), and a[3] means element at the third position (i.e., Japan).

print(a[1])
print(a[3])

In the next line, we used the special operator Range (or Colon). It prints the elements from 1 through 3 (i.e., 1, 2, 3)

print(a[1:3])

Access using Vector

This example access the Vector elements using another Vector in R.

# R Vector Elements Accessing
a <-  c("India", "China", "Japan", "UK", "USA", "Russia", "Sri Lanka") 
print(a)

b <- c(2, 4, 6)
print(a[b])

print(a[c(5, 7)])

print(a[c(7, 4, 1)])

We declared a vector of numbers 2, 4, 6

b <- c(2, 4, 6)

In the next line, we used those numbers as the index position to access the Vector a elements. It means, prints the elements at index position 2, 4, and 6.

print(a[b])
R Vector 6

Using Negative Values in R

Accessing the Vector elements using Negative values and the Boolean values. In R Vectors, Negative index position is used to omit those values.

# R Vector Elements Accessing
a <-  c("India", "China", "Japan", "UK", "USA", "Russia", "Sri Lanka") 
print(a)

b <- c(-3, -7)
print(a[b])

print(a[c(-4, -6, -7)])

print(a[c(TRUE, FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)])
R Vector 7

First, we declared a vector of negative numbers -3 and -7

b <- c(-3, -7)

In the next line, we used those numbers as the index position to access the Vector a elements. It means, prints the Vector elements except for the values at index position 3 and 7.

print(a[b])

In the next line, we declared a Boolean vector. We used those Boolean values as the index position to access the Vector a elements. Here, TRUE means print the value, and FALSE means don’t print. It means print elements at positions 1, 3, 4, 6.

print(a[c(TRUE, FALSE, TRUE, TRUE, FALSE, TRUE, FALSE)])

Use Character Vectors as Index

In this example, we show how to access the R Vector elements using Character Vectors Index values. Here, we declare a vector with alphabet indexes that can help us extract the vector elements using the alphabets.

# R Vector Elements Accessing
v <-  c("a" = 10, "b" = 20, "c" = 30, "d" = -15, "e" = 40) 
print(v)

print(v["a"])

print(v["d"])

print(v[c("a", "c")])
R Vector 8

Manipulate R Vector Elements

In R Programming, we can manipulate the Vector elements in following ways:

# R Vector Elements Manipulation
a <-  c(10, 20, 30, -15, 40, -25, 60, -5) 
print(a)

a[7] <- 77 
print(a)

a[a < 0] <- 99
print(a)

# Truncating the Vector Elements
a <- a[1:5]
print(a)

# Deleting Vector
a <- NULL
print(a)
R Vector 9

Assigning 77 to vector element at position 7.

a[7] <- 77

It will assign 99 to all the elements whose values are less than 0. Here a < 0 will check whether the element is less than zero or not, and if the condition is true, then that element will be replaced by 99.

a[a < 0] <- 99

In vector Slicing, the first integer value is the index position where the slicing will start, and the second is the index position of the slicing will end.

a <- a[1:5]

It removes the vector completely

a <- NULL

Important Functions of Vector

The following functions are some of the most useful functions supported by the Vectors in R programming.

  • typeof(Vector): Returns the data type of the vector.
  • Sort(Vector): Sort the items in the Ascending order.
  • length(Vector): Counts the number of elements in a vector.
  • head(Vector, limit): Returns the top six elements (if you Omit the limit). If you specify the limit as 4 then, it returns the first 4 elements.
  • tail(Vector, limit): It returns the last six elements (if you Omit the limit). If you specify the limit as 2, then it returns the last two elements.
# R Vector Elements Accessing
a <-  c(10, 20, 30, -15, 40, -25, 60, -5) 
print(a)

# Some of the Important Functions
typeof(a)
length(a)

head(a)
head(a, 4)

tail(a)
tail(a, 3)

x <- sort(a)
print(x)
R Vector 10

Arithmetic Operations on R Vector

Using Arithmetic Operators on Vectors to perform arithmetic operations.

a <-  c(10, 20, 30, 40)
b <-  c(12, 26, 38, 44)

print(a + b)

print(b - a)

print(a * b)

print (2 * a)

d <- c(12, 44)
print(a + d)
R Vector 11

We declared two numeric vectors of the same length

a <-  c(10, 20, 30, 40)
b <-  c(12, 26, 38, 44)

Next, we performed addition, subtraction and multiplication on this R vectors. Here a + b means (10 + 12, 20 + 26, 30 + 38, 40 + 44) = (22, 46, 38, 44)

print(a + b)
print(b - a)
print(a * b)

The above things will work as long as the vector length is the same. But, if the lengths are different, then vector element recycling will happen. It will travel and multiply each element with 2 until it finishes the vector elements.

print (2 * a)

Next, we declared a vector d of two elements and performed the addition. Here a + d means (10 + 12, 20 + 44, 30 + 12, 40 + 44) because we have only two elements in d so those two elements will be repeated.

d <- c(12, 44)
print(a + d)