Hello Rui,
Yes, it should be the one I want. I modified the code as:
for(i in grep("data", names(df))) {
? try2.un$ab2 <-
? ? ifelse(grepl("ab2",? [i]),? ?[i], NA)
}
But I got error message:?
Error: unexpected '[' in:
"? try2.un$ab2 <-
? ? ifelse(grepl("ab2",["
I think I use [i] in a wrong way. Do you have any suggestion?
Thanks,
Kai On Tuesday, November 15, 2022 at 10:54:08 AM PST, Rui Barradas
<ruipbarradas at sapo.pt> wrote:
?s 16:18 de 15/11/2022, Kai Yang via R-help escreveu:> Hi Team,
> I can write a for loop like this:
> for (i in columns(df)){
>? ? ......
> }
>
> But it will working on all column in dataframe df. If I want to work on
some of specific fields (say: the fields' name content 'date'), how
should I modify the for loop? I changed the code below, but it doesn't work.
> for (i in columns(df) %in% 'date' ){
>? ? .....
> }
>
>
> Thank you,
> Kai
>
> ??? [[alternative HTML version deleted]]
>
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Hello,
Something like this?
for(i in grep("date", names(df))) {
? #
}
Hope this helps,
Rui Barradas
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