How to Append Data Frames in R

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Here are two ways to append data frames in R.

  1. Using rbind() function
  2. Using nrow() function

Method 1: Using the rbind() function

The easiest way to append data frames in R is to the “rbind()” function. The “rbind()” function appends all records from the second data frame at the end of the first data frame.

Syntax

rbind(a, b)

Parameters

  1. The a is input data.
  2. The b is the data that needs to be binded.

Example 1: Appending data frames in R

data("cars")

df1 <- head(cars)
df2 <- tail(cars)

cat("First Data Frame: ", "\n")
df1
cat("Second Data Frame: ", "\n")
df2

appendedDf <- rbind(df1, df2)
cat("The appended data frame", "\n")
appendedDf

Output

First Data Frame:
  speed   dist
1   4      2
2   4     10
3   7      4
4   7     22
5   8     16
6   9     10
Second Data Frame:
   speed  dist
45  23     54
46  24     70
47  24     92
48  24     93
49  24    120
50  25     85
The appended data frame
   speed  dist
1    4     2
2    4    10
3    7     4
4    7    22
5    8    16
6    9    10
45  23    54
46  24    70
47  24    92
48  24    93
49  24   120
50  25    85

Example 2: Append a Column to a data frame

To append a column to the data frame in R, use the symbol $ to append the data frame variable and add a column. 

data("cars")

df <- head(cars)

cat("The Data Frame: ", "\n")
df

mileage <- c(70, 80, 90, 100, 110, 120)
cat("After Appendung a new column Data Frame: ", "\n")

df$mileage <- mileage
df

Output

The Data Frame:
  speed   dist
1   4      2
2   4     10
3   7      4
4   7     22
5   8     16
6   9     10
After Appendung a new column Data Frame:
  speed   dist   mileage
1   4      2      70
2   4     10      80
3   7      4      90
4   7     22     100
5   8     16     110
6   9     10     120

Example 3: Append Row to Data Frame

Use the rbind() function to combine the data frame with the row to be appended.

# Create a data frame.
df <- data.frame(
  Name = c("Ankit", "Rushabh", "Dhaval"),
  Age = c(20, 25, 28)
)

# Append a row to the data frame.
new_row <- data.frame(
  Name = "Krunal",
  Age = 30
)

# Combine the data frame with the row to be appended.
df <- rbind(df, new_row)

# Print the data frame.
print(df)

Output

   Name   Age
1  Ankit   20
2  Rushabh 25
3  Dhaval  28
4  Krunal  30

Method 2: Using the nrow() function

You can use the nrow() function to append a row to the end of a given data frame.

The expression for appending data frames is df[nrow(df) + 1,] = c(value1, value2, …).

Syntax

nrow(obj)

Parameters

obj: It can be a vector, array, data frame, NULL, or matrix.

Example

df <- data.frame(
        var1 = c(11, 21, 19),
        var2 = c(18, 46, 29),
        var3 = c(20, 23, 7)
      )
df

cat("After appending a row using rnow() function", "\n")

df[nrow(df) + 1, ] <- c(2, 52, 4)
df

Output

  var1  var2  var3
1  11    18    20
2  21    46    23
3  19    29    7
After appending a row using rnow() function
  var1  var2  var3
1  11   18    20
2  21   46    23
3  19   29    7
4   2   52    4

That’s it.

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