Rename whole data sets

[IsBeth]

Hello! Sorry if my question seems a bit stupid, cause I think it has to be easy, but I don't have enough knowhow...
I want to rename a character string in R which contains numbers. It's something like this:

"3435" "4364" a.s.o.

I want to change that so there are words before the numbers. There must be the same words for the whole length of the object, like this:

"mygenes_3435" "mygenes_4364"...

is there a command to do this? Would it be similar if I wanted to rename a data.frame for example? I really need help, it's very urgent! =(

[Jeremy]

call that string MyString
NewString <- paste("mygenes_", MyString, sep="")

If that is a column of a data frame called DF
DF$MyString <- paste("mygenes_", DF$MyString, sep="")

[dpryan]

Another option is sprintf:

NewString <- sprintf("mygenes_%s", MyString)

Paste is easier for concatenating two strings like this, but should you want to merge multiple things (possibly with formatting), then you'll find sprintf very helpful.