Add Column to R Data Frame
To add a new column to R Data Frame, use dollar sign $
as shown in the following syntax.
mydataframe$newcolumn <- vector_name
In this tutorial, we will learn how to add a column to a Data Frame in R programming.
where
mydataframe
is the data frame to which we shall add a new column.newcolumn
is the name of the new column.vector_name
is the vector containing the values of new column.
Examples
1 – Add Column to R Data Frame
In this example, we will create a data frame DF1
and add a column to the data frame.
> DF1 = data.frame(V1= c(1, 5, 14, 23, 54), V2= c(9, 15, 85, 3, 42), V3= c(9, 7, 42, 87, 16)) > DF1 V1 V2 V3 1 1 9 9 2 5 15 7 3 14 85 42 4 23 3 87 5 54 42 16 > DF1$V4 = c(55, 66, 85, 12, 21) > DF1 V1 V2 V3 V4 1 1 9 9 55 2 5 15 7 66 3 14 85 42 85 4 23 3 87 12 5 54 42 16 21 >
Column V4
is successfully added to the data frame.
Example 2 – Add Column (with lesser length) to R Data Frame
In this example, we will create a data frame DF1
and add a column with number of rows less than the existing number of rows in the data frame.
> DF1 = data.frame(V1= c(1, 5, 14, 23, 54), V2= c(9, 15, 85, 3, 42), V3= c(9, 7, 42, 87, 16)) > DF1 V1 V2 V3 1 1 9 9 2 5 15 7 3 14 85 42 4 23 3 87 5 54 42 16 > DF1$V4 = c(55, 66, 85, 12) Error in `$<-.data.frame`(`*tmp*`, V4, value = c(55, 66, 85, 12)) : replacement has 4 rows, data has 5 >
You will get an error “replacement has 4rows, data has 5”.