1 Create Vectors in R

Create a vector with numeric (or double) elements:

vec1 = c(1, 4, 9, 16, 25, 36, 49, 64, 81, 100)
vec1

 [1]   1   4   9  16  25  36  49  64  81 100

Create a vector with character elements:

vec2 = c("Red", "Blue", "Green")
vec2

[1] "Red"   "Blue"  "Green"

Create an empty vector:

vec3 = rep(NA, times = 5)
vec3

[1] NA NA NA NA NA

Assign values to (or edit) some index of a vector:

vec4 = rep(NA, times = 5)
vec4[1:3] = 10
vec4[5] = 100
vec4

[1]  10  10  10  NA 100

• type is numeric, integer, character, logical, or complex.

• See examples below.

2 Check Vectors in R

Check the length of a vector:

vec1 = c(1, 4, 9, 16, 25)
length(vec1)

[1] 5

Set or change the length of a vector:

vec1 = c(1, 4, 9, 16, 25)
vec1

[1]  1  4  9 16 25

length(vec1) = 10
vec1

 [1]  1  4  9 16 25 NA NA NA NA NA

length(vec1) = 3
vec1

[1] 1 4 9

Check if an object is a vector:

vec1 = c(1, 4, 9)
is.vector(vec1) # This will return TRUE or FALSE.

[1] TRUE

Check the data type or mode of a vector:

vec1 = c(10, 20, 30)
typeof(vec1)

[1] "double"

vec2 = c("A", "B", "C")
typeof(vec2)

[1] "character"

Check if a vector’s components are of a type/mode:

vec1 = c(10, 20, 30)
is.double(vec1)

[1] TRUE

is.integer(vec1)

[1] FALSE

vec2 = c("A", "B", "C")
is.character(vec2)

[1] TRUE

3 Coerce (into) Vectors in R

Coerce an object into a vector:

This example turns a matrix into a vector.

mat1 = matrix(c(1, 2, 4, 8, 16, 32),
              nrow = 3, byrow = TRUE)
mat1

     [,1] [,2]
[1,]    1    2
[2,]    4    8
[3,]   16   32

vec1 = as.vector(mat1) # This will turn into a vector by column.
vec1

[1]  1  4 16  2  8 32

Coerce a vector’s components into a different type/mode:

vec1 = c(10, 20, 30)
vec2 = as.integer(vec1)
typeof(vec2)

[1] "integer"

vec3 = as.character(vec1)
typeof(vec3)

[1] "character"

4 Add and Subtract Vectors in R

Add or subtract vectors of the same lengths:

vec1 = c(1, 2, 3, 4, 5)
vec1

[1] 1 2 3 4 5

vec2 = c(1:5)
vec2

[1] 1 2 3 4 5

# Add two vectors
vec1 + vec2

[1]  2  4  6  8 10

# Subtract a number from a vector
vec1 - 1

[1] 0 1 2 3 4

You can also add or subtract vectors of different lengths:

vec3 = rep(2, times = 8)
vec3

[1] 2 2 2 2 2 2 2 2

vec4 = c(1, 100, 1000)
vec4

[1]    1  100 1000

vec5 = c(0,1)
vec5

[1] 0 1

vec3 + vec4

Warning in vec3 + vec4: longer object length is not a multiple of shorter
object length

[1]    3  102 1002    3  102 1002    3  102

vec3 - vec5

[1] 2 1 2 1 2 1 2 1

5 Multiply and Divide Vectors in R

Multiply or divide vectors of the same lengths:

vec1 = c(6, 7, 8, 9, 10)
vec1

[1]  6  7  8  9 10

vec2 = c(6:10)
vec2

[1]  6  7  8  9 10

# Multiple two vectors
vec1 * vec2

[1]  36  49  64  81 100

# Divide a vector by a number
vec1 / 10

[1] 0.6 0.7 0.8 0.9 1.0

You can also multiply or divide vectors of different lengths:

vec3 = rep(2, times = 8)
vec3

[1] 2 2 2 2 2 2 2 2

vec4 = c(1, 2, 3)
vec4

[1] 1 2 3

vec5 = c(1, 2)
vec5

[1] 1 2

# Multiply two vectors
vec3 * vec4

Warning in vec3 * vec4: longer object length is not a multiple of shorter
object length

[1] 2 4 6 2 4 6 2 4

# Divide a vector by another
vec3 / vec5

[1] 2 1 2 1 2 1 2 1

6 Join Strings from Character Vectors in R

For character vectors, you can use the paste() or paste0() (with no spacing) to join components:

vec1 = c("Red", "Blue", "Green")
vec2 = rep("Color", times = 3)
vec1; vec2

[1] "Red"   "Blue"  "Green"

[1] "Color" "Color" "Color"

paste(vec1, vec2)

[1] "Red Color"   "Blue Color"  "Green Color"

# paste0 will not add spacing when joining the strings
paste0(vec1, vec2)

[1] "RedColor"   "BlueColor"  "GreenColor"

paste("The color", vec1, "is a primary color.")

[1] "The color Red is a primary color."   "The color Blue is a primary color." 
[3] "The color Green is a primary color."