R move index column to first column

Question

I have following data frame:

              RMSE
A         0.03655830
B         0.24513014
C         0.02009853
D         0.02223135

I want to move column that has A,B,C,D to be the first column and add an index to the data.frame.

score 29 · Answer 1 · answered Apr 04 '16 at 08:05

29

try this:

df <- cbind(newColName = rownames(df), df)
rownames(df) <- 1:nrow(df)

hope this is what you meant, the result will be:

  newColName       RMSE
1          A 0.03655830
2          B 0.24513014
3          C 0.02009853
4          D 0.02223135

answered Apr 04 '16 at 08:05

cccmir

2

Also `rownames(df) <- NULL` – Sotos Apr 04 '16 at 08:42
@Sotos Doesn't this do the same thing as `rownames(df) <- 1:nrow(df)`? – Adam_G Dec 05 '22 at 23:58
@Adam_G Yes. Thats what they have in their answer. I wrote that as an alternative – Sotos Dec 06 '22 at 07:40

1 Answers1