How can I use a file name as column name in R?

Question

I have multiple files to concatenate its columns in a dataframe, but for each column I need to use the file name as column name. How should I do it?

For example:

In the file "amostra4A" I have two columns named "V1" and "V2", but I want to replace it for the file name and repeat the same way for the last files.

Sorry for same mistakes, I'm new in R.

You can't have duplicate column names i.e. if you are replacing V1 and V2 with 'amostra4A', it will be duplicate names which are not allowed in data.frames. Do you have list of data.frames or just objects created in the global env? — akrun
– akrun, Commented Nov 8, 2022 at 17:46
Greetings! Usually it is helpful to provide a minimally reproducible dataset for questions here so people can troubleshoot your problems. One way of doing this is by using the dput function. You can find out how to use it here: youtu.be/3EID3P1oisg — Shawn Hemelstrand
– Shawn Hemelstrand, Commented Nov 15, 2022 at 3:18

G. Grothendieck · Accepted Answer · 2022-11-08 19:30:07Z

0

Put the data frames into a list L such that the name of each data frame is the name you want to use. We will use BOD which comes with R. Convert the list to a data frame and change the names.

L <- list(A = BOD, B = BOD)
DF <- as.data.frame(L)
names(DF) <- sub("\\..*", "", names(DF))
DF
##   A    A B    B
## 1 1  8.3 1  8.3
## 2 2 10.3 2 10.3
## 3 3 19.0 3 19.0
## 4 4 16.0 4 16.0
## 5 5 15.6 5 15.6
## 6 7 19.8 7 19.8

That said it is normally assumed that column names in a data frame are unique and you are bound to run into subsequent problems if you do the above. Better would be to use a prefix of the A or B name followed by the column name so that the names are unique.

as.data.frame(L)
##   A.Time A.demand B.Time B.demand
## 1      1      8.3      1      8.3
## 2      2     10.3      2     10.3
## 3      3     19.0      3     19.0
## 4      4     16.0      4     16.0
## 5      5     15.6      5     15.6
## 6      7     19.8      7     19.8

Note that if the data frames are sitting loose in the global environment an alternative to creating L is:

A <- BOD
B <- BOD
L <- mget(c("A", "B"))

edited Nov 8, 2022 at 19:30

answered Nov 8, 2022 at 18:23

G. Grothendieck

273k18 gold badges221 silver badges365 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Thiago de Araujo Over a year ago

Hello, thank you for helping me, but it didn't work. I have multiples files and each with two columns, I whant to concatenate all columns and put the original file name as column name.

G. Grothendieck Over a year ago

Please read the information at the top of the r tag page on how to ask a question. You need to provide a reproducible example that anyone else can run. Since that was not provided I provided one in the answer and it does work on the example I provided.

Collectives™ on Stack Overflow

How can I use a file name as column name in R?

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related