Print one column of data frame with row names

Question

Consider a data frame with custom row names:

> data <- data.frame(a=1:3,b=2:4,c=3:5,row.names=c("x","y","z")) > data   a b c x 1 2 3 y 2 3 4 z 3 4 5 

If I select more than one column, R prints them along with the row names:

> data[,c("a","c")]   a c x 1 3 y 2 4 z 3 5 

But if I select only one column, R prints it as a simple vector, without the row names:

> data[,"c"] [1] 3 4 5 

My question is, how do I tell R to print one column in the same way it prints multiple columns, that is, with the row names?

Answer 1

You can use the drop argument (see also ?'['):

data[,"c", drop=FALSE] 

gives you a data.frame

  c x 3 y 4 z 5 

Answer 2

An even easier way is data['c'], which will result in the same output:

  c x 3 y 4 z 5