R - Vector - GeeksforGeeks

R – Vector

Last Updated : 22 Apr, 2020

R programming is one of the most popular languages when it comes to data science, statistical computations or scientific research. R programming is widely used in machine learning and it is very efficient and user-friendly. It provides flexibility in doing big statistical operations with a few lines of code.

Vectors in R are the same as the arrays in C language which are used to hold multiple data values of the same type. One major key point is that in R the indexing of the vector will start from ‘1’ and not from ‘0’. We can create numeric vectors and character vectors as well.

Vectors-in-R

Types of vectors

Vectors are of different types which are used in R. Following are some of the types of vectors:

Numeric vectors
Numeric vectors are those which contain numeric values such as integer, float, etc.

# R program to create numeric Vectors
  
# creation of vectors using c() function.
v1 <- c(4, 5, 6, 7)
  
# display type of vector
typeof(v1)
  
# by using 'L' we can specify that we want integer values.
v2 <- c(1L, 4L, 2L, 5L) 
  
# display type of vector
typeof(v2)

Output:

[1] "double"
[1] "integer"

Character vectors
Character vectors contain alphanumeric values and special characters.
# R program to create Character Vectors

# by default numeric values
# are converted into characters
v1 <- c('geeks', '2', 'hello', 57)

# Displaying type of vector
typeof(v1)
Output:
```
[1] "character"
```
Logical vectors
Logical vectors contain boolean values such as TRUE, FALSE and NA for Null values.
# R program to create Logical Vectors

# Creating logical vector
# using c() function
v1 <- c(TRUE, FALSE, TRUE, NA)

# Displaying type of vector
typeof(v1)
Output:
```
[1] "logical"
```

Creating a vector

There are different ways of creating vectors. Generally, we use ‘c’ to combine different elements together.

# R program to create Vectors
  
# we can use the c function
# to combine the values as a vector.
# By default the type will be double
X <- c(61, 4, 21, 67, 89, 2)
cat('using c function', X, '\n')
  
# seq() function for creating
# a sequence of continuous values.
# length.out defines the length of vector.
Y <- seq(1, 10, length.out = 5) 
cat('using seq() function', Y, '\n') 
  
# use':' to create a vector 
# of continuous values.
Z <- 2:7
cat('using colon', Z)

Output:

using c function 61 4 21 67 89 2 
using seq() function 1 3.25 5.5 7.75 10 
using colon 2 3 4 5 6 7

Accessing vector elements

Accessing elements in a vector is the process of performing operation on an individual element of a vector. There are many ways through which we can access the elements of the vector. The most common is using the ‘[]’, symbol.

Note: Vectors in R are 1 based indexing unlike the normal C, python, etc format.

# R program to access elements of a Vector
  
# accessing elements with an index number.
X <- c(2, 5, 18, 1, 12)
cat('Using Subscript operator', X[2], '\n')
  
# by passing a range of values
# inside the vector index.
Y <- c(4, 8, 2, 1, 17)
cat('Using combine() function', Y[c(4, 1)], '\n')
  
# using logical expressions
Z <- c(5, 2, 1, 4, 4, 3)
cat('Using Logical indexing', Z[Z>4])

Output

Using Subscript operator 5 
Using combine() function 1 4 
Using Logical indexing 5

Modifying a vector

Modification of a Vector is the process of applying some operation on an individual element of a vector to change its value in the vector. There are different ways through which we can modify a vector:

# R program to modify elements of a Vector
  
# Creating a vector
X <- c(2, 7, 9, 7, 8, 2)
  
# modify a specific element
X[3] <- 1
X[2] <-9
cat('subscript operator', X, '\n')
  
# Modify using different logics.
X[X>5] <- 0
cat('Logical indexing', X, '\n')
  
# Modify by specifying 
# the position or elements.
X <- X[c(3, 2, 1)]
cat('combine() function', X)

Output

subscript operator 2 9 1 7 8 2 
Logical indexing 2 0 1 0 0 2 
combine() function 1 0 2

Deleting a vector

Deletion of a Vector is the process of deleting all of the elements of the vector. This can be done by assigning it to a NULL value.

# R program to delete a Vector
  
# Creating a Vector
M <- c(8, 10, 2, 5)
  
# set NULL to the vector
M <- NULL 
cat('Output vector', M)

Output:

Output vector NULL

Sorting elements of a Vector

sort() function is used with the help of which we can sort the values in ascending or descending order.

# R program to sort elements of a Vector
  
# Creation of Vector
X <- c(8, 2, 7, 1, 11, 2)
  
# Sort in ascending order
A <- sort(X)
cat('ascending order', A, '\n')
  
# sort in descending order 
# by setting decreasing as TRUE
B <- sort(X, decreasing = TRUE)
cat('descending order', B)

Output:

ascending order 1  2  2  7  8 11
descending order 11  8  7  2  2  1

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Related Articles

Types of vectors

Creating a vector

Accessing vector elements

Modifying a vector

Deleting a vector

Sorting elements of a Vector