Related Articles

# Reverse the values of an Object in R Programming – rev() Function

• Last Updated : 17 Jun, 2020

rev() function in R Language is used to return the reverse version of data objects. The data objects can be defined as Vectors, Data Frames by Columns & by Rows, etc.

Syntax: rev(x)

Parameter:
x: Data object

Returns: Reverse of the data object passed

Example 1:

 # R program to reverse a vector  # Create a vectorvec <- 1:5                           vec    # Apply rev() function to vector    vec_rev <- rev(vec)                      vec_rev

Output:

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

Example 2: Reverse Columns of a Data Frame

 # R program to reverse # columns of a Data Frame  # Creating a data.framedata <- data.frame(x1 = 1:5,                               x2 = 6:10,                   x3 = 11:15)data    # Print reversed example data framedata_rev <- rev(data)                    data_rev

Output:

x1 x2 x3
1  1  6 11
2  2  7 12
3  3  8 13
4  4  9 14
5  5 10 15

x3 x2 x1
1 11  6  1
2 12  7  2
3 13  8  3
4 14  9  4
5 15 10  5

Example 3: Reverse Rows of a Data Frame

 # R program to reverse# rows of a data frame  # Creating a data framedata <- data.frame(x1 = 1:5,                               x2 = 6:10,                   x3 = 11:15)data    # Calling rev() & apply() functions combineddata_rev_row_a <- apply(data, 2, rev)    data_rev_row_a   # Alternative without rev()  data_rev_row_b <- data[nrow(data):1, ]   data_rev_row_b

Output:

x1 x2 x3
1  1  6 11
2  2  7 12
3  3  8 13
4  4  9 14
5  5 10 15
x1 x2 x3
[1,]  5 10 15
[2,]  4  9 14
[3,]  3  8 13
[4,]  2  7 12
[5,]  1  6 11
x1 x2 x3
5  5 10 15
4  4  9 14
3  3  8 13
2  2  7 12
1  1  6 11

My Personal Notes arrow_drop_up