Applying names to dataframe column variables

Question

I have a data frame with 563 columns in which I would like to change the names of column variables in all except the first 2 columns using a character vector(Cnames) of length 561. I tried using:

colnames(df[,3:563]) <- Cnames

But nothing happens here. But if I try changing the names of all column variables as follows then renaming works:

CoName <- c("char0", "char01", Cnames)
colnames(df) <- CoName

Can someone tell me why this happens? Thanks in advance.

I tried that but get an error: Error in colnames(df)[, 3:563] <- Cnames : incorrect number of subscripts on matrix — user3922546, Aug 27 '14 at 09:37

score 3 · Answer 1 · answered Aug 27 '14 at 09:35

3

You can do

colnames(df)[3:563] <- Cnames

which will work.

I'm not familiar with the R memory model, but I suspect that the call to colnames(df[,3:563]) returns a new, temporary object which has nothing to do with the original data frame. On the other hand, colnames(df) will allow you to directly update the reference in the data frame.

answered Aug 27 '14 at 09:35

martin

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or make it general `colnames(df)[3:ncol(df)] <- Cnames` – user1436187 Aug 27 '14 at 09:42
See [here](http://stackoverflow.com/questions/23427925/difference-between-namesdf1-and-namesdf1) on why this is happening – David Arenburg Aug 27 '14 at 09:44

Applying names to dataframe column variables

1 Answers1