How to add a name column of character vectors to a data frame in R

Question

I have a data frame built as such:

dput(au.weighted.scores)

    structure(list(AUDIT = c(0.283333333333333, 0.283333333333333, 
    0.183333333333333, 0.3, 0.2625), CORC = c(0.2, 0, 0.76, 0.82, 
    0.545), GOV = c(0.82, 0.82, 0.74, 0.66, 0.76), PPS = c(0.2, 0.2, 
    0.2, 0.266666666666667, 0.216666666666667), TMSC = c(0.525, 0.525, 
    0.25, 0.158333333333333, 0.189583333333333), TRAIN = c(0.233333333333333, 
    0.233333333333333, 0.216666666666667, 0.266666666666667, 0.2375
    )), .Names = c("AUDIT", "CORC", "GOV", "PPS", "TMSC", "TRAIN"
    ), row.names = c(NA, -5L), class = "data.frame")

I need to add a column of names that accompany the rows of this data frame. The column is c("Group1", "Group2", "Group3", "Group4", "Group5").

How can I add this column of names in with it's own column name like "Group_Name"?

The end result would look like this:

au.weighted.scores

 Group_Name     AUDIT  CORC  GOV       PPS      TMSC     TRAIN
1 Group1        0.2833333 0.200 0.82 0.2000000 0.5250000 0.2333333
2 Group2        0.2833333 0.000 0.82 0.2000000 0.5250000 0.2333333
3 Group3        0.1833333 0.760 0.74 0.2000000 0.2500000 0.2166667
4 Group4        0.3000000 0.820 0.66 0.2666667 0.1583333 0.2666667
5 Group5        0.2625000 0.545 0.76 0.2166667 0.1895833 0.2375000

`au.weighted.scores %>% mutate(Group_Name = c("Group1", "Group2", "Group3", "Group4", "Group5"))` — alistaire, Aug 27 '17 at 04:57
Possible duplicate of [How to add new column to an dataframe (to the front not end)?](https://stackoverflow.com/questions/19508256/how-to-add-new-column-to-an-dataframe-to-the-front-not-end) or this one: https://stackoverflow.com/questions/10150579/adding-a-column-to-a-data-frame — mt1022, Aug 27 '17 at 05:24

score 2 · Accepted Answer · answered Aug 27 '17 at 04:55

We can create the vector with paste and cbind it to the original dataset

cbind(Group_Name = paste0("Group", seq_len(nrow(au.weighted.scores))), au.weighted.scores)
#  Group_Name     AUDIT  CORC  GOV       PPS      TMSC     TRAIN
#1     Group1 0.2833333 0.200 0.82 0.2000000 0.5250000 0.2333333
#2     Group2 0.2833333 0.000 0.82 0.2000000 0.5250000 0.2333333
#3     Group3 0.1833333 0.760 0.74 0.2000000 0.2500000 0.2166667
#4     Group4 0.3000000 0.820 0.66 0.2666667 0.1583333 0.2666667
#5     Group5 0.2625000 0.545 0.76 0.2166667 0.1895833 0.2375000

Note that we used cbind so that the column will be the in the first position as in the expected output

Simple and effective. I ended up using it this way: au.weighted.scores <- cbind(AU = paste0(au.names), au.weighted.scores) \\ where au.names is a character vectors of the names I wanted to include. — Zach, Aug 27 '17 at 05:28

score 2 · Answer 2 · answered Aug 27 '17 at 04:56

2

If you just want the simplest possible way, I would use this:

au.weighted.scores$Group_Name <- paste0("Group", 1:5)

answered Aug 27 '17 at 04:56

Stedy

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How to add a name column of character vectors to a data frame in R

2 Answers2