Here, we show some basic data operations in R such as sort, reverse, unique values, duplicate values, rank, head values, and tail values.

All functions are from the "base" package, except head() and tail() which are from the "utils" package.

Summary Functions for Basic Data Operations in R
Function	Usage
`sort()`	Sort data
`rev()`	Reverse vector elements
`unique()`	Return unique elements
`duplicated()`	Find duplicated elements
`rank()`	Rank in numeric or alphanumeric order
`head()`	See first few values of data
`tail()`	See last few values of data

1 Sort or Reverse Vectors in R

Sort letters or words in a vector:

vec1 = c("B", "C", "E", "A", "D")
sort(vec1)

[1] "A" "B" "C" "D" "E"

Sort numbers:

vec2 = c(4, 2, 7, 8, 5, 3, 2, 7)
sort(vec2)

[1] 2 2 3 4 5 7 7 8

Sort numbers in decreasing order:

sort(vec2, decreasing = TRUE)

[1] 8 7 7 5 4 3 2 2

Reverse order of vector elements:

vec3 = c(39, 32, 43, 46, 48, 35)
rev(vec3)

[1] 35 48 46 43 32 39

2 List Unique Vector Elements or Find Duplicated Vector Elements in R

Get unique elements:

The unique elements will be listed.

vec1 = c(4, 2, 2, 7, 8, 5, 3, 3)
unique(vec1)

[1] 4 2 7 8 5 3

Find duplicated values:

TRUE will be returned in the positions of duplicated elements.

duplicated(vec1)

[1] FALSE FALSE  TRUE FALSE FALSE FALSE FALSE  TRUE

Return numeric rank order of elements:

Numeric ranks will be returned with "1" for the lowest number.

vec1 = c(14, 2, 70, 18, 777)
rank(vec1)

[1] 2 1 4 3 5

Return alphanumeric rank order of elements:

Alphanumeric ranks will be returned with "1" for the first number on the alphanumeric order.

vec2 = c("Pen", "Fan", "Art", "Book")
rank(vec2)

[1] 4 3 1 2

vec3 = c(14, 2, 70, "Pen", 18, "Art", 777)
rank(vec3)

[1] 1 3 4 7 2 6 5

Using the dataframe below:

dtf = data.frame(Letter = c("A", "B", "C", "D", "E", "F"),
                 Number = c(1, 2, 3, 4, 5, 6))
dtf

  Letter Number
1      A      1
2      B      2
3      C      3
4      D      4
5      E      5
6      F      6

Return only the first 3 rows:

head(dtf, 3)

  Letter Number
1      A      1
2      B      2
3      C      3

Return only the last 2 rows:

tail(dtf, 2)

  Letter Number
5      E      5
6      F      6

Return only the first 3 or last 3 values of a vector:

vec = c(4, 6, 2, 8, 9, 5)
head(vec, 3)

[1] 4 6 2

tail(vec, 3)

[1] 8 9 5

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