In this article, we will discuss how to combine two dataframes with different columns in R Programming Language.
Method 1 : Using plyr package
The “plyr” package in R is used to work with data, including its enhancements and manipulations. It can be loaded and installed into the working space by the following command :
install.packages(“plyr”)
rbind.fill() method in R is an enhancement of the rbind() method in base R, is used to combine data frames with different columns. The column names are number may be different in the input data frames. Missing columns of the corresponding data frames are filled with NA. The output data frame contains a column only if it is present in any of the data frame.
Syntax:
rbind.fill( df1, df2)
The following properties are maintained by the rbind.fill() method :
- The data frames are appended in the order of their specification in the function.
- The total number of columns is equivalent to the summation of a number of columns of both the data frames.
- The total number of rows are equivalent to the summation of number of rows of both the data frames.
- The appearance of columns is in the order of data frame arguments declaration during function call.
- Empty cells are created in the missing columns.
Example:
# loading the required library library("plyr")
# declaring first data frame data_frame1 <- data.frame(col1 = c(2,4,6),
col2 = c(4,6,8),
col3 = c(8,10,12),
col4 = LETTERS[1:3])
print ("First Dataframe")
print (data_frame1)
# declaring second data frame data_frame2 <- data.frame(col4 = letters[1:4],
col5 = TRUE)
print ("Second Dataframe")
print (data_frame2)
print ("Combining Dataframe")
# binding data frames rbind.fill(data_frame1,data_frame2)
|
Output
[1] "First Dataframe" col1 col2 col3 col4 1 2 4 8 A 2 4 6 10 B 3 6 8 12 C [1] "Second Dataframe" col4 col5 1 a TRUE 2 b TRUE 3 c TRUE 4 d TRUE [1] "Combining Dataframe" [1] "First Dataframe" col1 col2 col3 col4 1 2 4 8 20 2 4 6 10 16 3 6 8 12 14 [1] "Second Dataframe" col5 col6 1 a TRUE 2 b TRUE 3 c TRUE 4 d TRUE [1] "Combining Dataframe" col1 col2 col3 col4 col5 1 2 4 8 A NA 2 4 6 10 B NA 3 6 8 12 C NA 4 NA NA NA a TRUE 5 NA NA NA b TRUE 6 NA NA NA c TRUE 7 NA NA NA d TRUE
Method 2: Using dplyr package
The “dplyr” package in R is used to work with data, including its enhancements and manipulations. It can be loaded and installed into the working space by the following command :
install.packages(“dplyr”)
The bind_rows() method is used to combine data frames with different columns. The column names are number may be different in the input data frames. Missing columns of the corresponding data frames are filled with NA. The output data frame contains a column only if it is present in any of the data frame.
Syntax:
bind_rows(df1, df2)
The following properties are maintained by the bind_rows() method :
- The data frames are appended in the order of their specification in the function.
- The total number of columns are equivalent to the summation of number of columns of both the data frames.
- The total number of rows are equivalent to the summation of number of rows of both the data frames.
Example:
# loading the required library library("dplyr")
# declaring first data frame data_frame1 <- data.frame(col1 = c(2,4,6),
col2 = c(4,6,8),
col3 = c(8,10,12),
col4 = c(20,16,14))
print ("First Dataframe")
print (data_frame1)
# declaring second data frame data_frame2 <- data.frame(col5 = letters[1:4],
col6 = TRUE)
print ("Second Dataframe")
print (data_frame2)
print ("Combining Dataframe")
# binding data frames bind_rows(data_frame1,data_frame2)
|
Output
[1] "First Dataframe" col1 col2 col3 col4 1 2 4 8 20 2 4 6 10 16 3 6 8 12 14 [1] "Second Dataframe" col5 col6 1 a TRUE 2 b TRUE 3 c TRUE 4 d TRUE [1] "Combining Dataframe" col1 col2 col3 col4 col5 col6 1 2 4 8 20 <NA> NA 2 4 6 10 16 <NA> NA 3 6 8 12 14 <NA> NA 4 NA NA NA NA a TRUE 5 NA NA NA NA b TRUE 6 NA NA NA NA c TRUE 7 NA NA NA NA d TRUE
In case, any of the column name is same in both of the input data frames, then the following properties are encountered :
- The class of the common column should be same in both the data frames, otherwise an error is encountered.
- In this case, the total number of columns in the output data frame should be equivalent to the total input columns minus the intersecting columns.
Example:
# loading the required library library("dplyr")
# declaring first data frame data_frame1 <- data.frame(col1 = c(2,4,6),
col2 = c(4,6,8),
col3 = c(8,10,12),
col4 = LETTERS[1:3])
print ("First Dataframe")
print (data_frame1)
# declaring second data frame data_frame2 <- data.frame(col4 = letters[1:4],
col5 = TRUE)
print ("Second Dataframe")
print (data_frame2)
print ("Combining Dataframe")
# binding data frames bind_rows(data_frame1,data_frame2)
|
Output
[1] "First Dataframe" col1 col2 col3 col4 1 2 4 8 A 2 4 6 10 B 3 6 8 12 C [1] "Second Dataframe" col4 col5 1 a TRUE 2 b TRUE 3 c TRUE 4 d TRUE [1] "Combining Dataframe" [1] "First Dataframe" col1 col2 col3 col4 1 2 4 8 20 2 4 6 10 16 3 6 8 12 14 [1] "Second Dataframe" col5 col6 1 a TRUE 2 b TRUE 3 c TRUE 4 d TRUE [1] "Combining Dataframe" col1 col2 col3 col4 col5 1 2 4 8 A NA 2 4 6 10 B NA 3 6 8 12 C NA 4 NA NA NA a TRUE 5 NA NA NA b TRUE 6 NA NA NA c TRUE 7 NA NA NA d TRUE