Hi Kai, You seem to be asking the same question again and again. This does not give us the warm feeling that you know what you want.
testdf<-data.frame(a=c("Negative","Positive","Neutral","Random","VUS"), b=c("No","Yes","No","Maybe","Yes"), c=c("Off","On","Off","Off","On"), d=c("Bad","Good","Bad","Bad","Good"), stringsAsFactors=FALSE) testdf match_strings<-c("Positive","VUS") testdf$b<-ifelse(testdf$a %in% match_strings,testdf$b,"") testdf$c<-ifelse(testdf$a %in% match_strings,testdf$c,"") testdf$d<-ifelse(testdf$a %in% match_strings,testdf$d,"") testdf I have assumed that you mean "zero length strings" rather than "zeros". Also note that your initial code was producing logical values that were never assigned to anything. Jim On Mon, May 31, 2021 at 2:29 AM Kai Yang via R-help <r-help@r-project.org> wrote: > > Hello List,I have a data frame which having the character columns: > > | a1 | b1 | c1 | d1 | > | a2 | b2 | c2 | d2 | > | a3 | b3 | c3 | d3 | > | a4 | b4 | c4 | d4 | > | a5 | b5 | c5 | d5 | > > > > I need to do: if a1 not = "Positive" and not = "VUS" then values of b1, c1 > and d1 will be zero out. And do the same thing for the a2 to a5 series. > I write the code below to do this. But it doesn't work. Would you please > correct my code? > Thank you, > Kai > > > for (i in 1:5) > { > if (isTRUE(try$a[i] != "Positive" && try$a[i] != "VUS")) > { > try$b[i]== '' > try$c[i] == '' > try$d[i]== '' > } > } > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.