Another way to make columns out of the stuff before and after the underscore, with NAs if there is no underscore, is
utils::strcapture("([^_]*)_(.*)", F1$text, proto=data.frame(Before_=character(), After_=character())) -Bill On Tue, Sep 22, 2020 at 4:25 PM Bert Gunter <bgunter.4...@gmail.com> wrote: > To be clear, I think Rui's solution is perfectly fine and probably better > than what I offer below. But just for fun, I wanted to do it without the > lapply(). Here is one way. I think my comments suffice to explain. > > > ## which are the non "_" indices? > > wh <- grep("_",F1$text, fixed = TRUE, invert = TRUE) > > ## paste "_." to these > > F1[wh,"text"] <- paste(F1[wh,"text"],".",sep = "_") > > ## Now strsplit() and unlist() them to get a vector > > z <- unlist(strsplit(F1$text, "_")) > > ## now cbind() to the data frame > > F1 <- cbind(F1, matrix(z, ncol = 2, byrow = TRUE)) > > F1 > ID1 ID2 text 1 2 > 1 A1 B1 NONE_. NONE . > 2 A1 B1 cf_12 cf 12 > 3 A1 B1 NONE_. NONE . > 4 A2 B2 X2_25 X2 25 > 5 A2 B3 fd_15 fd 15 > >## You can change the names of the 2 columns yourself > > Cheers, > Bert > > Bert Gunter > > "The trouble with having an open mind is that people keep coming along and > sticking things into it." > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) > > > On Tue, Sep 22, 2020 at 12:19 PM Rui Barradas <ruipbarra...@sapo.pt> > wrote: > > > Hello, > > > > A base R solution with strsplit, like in your code. > > > > F1$Y1 <- +grepl("_", F1$text) > > > > tmp <- strsplit(as.character(F1$text), "_") > > tmp <- lapply(tmp, function(x) if(length(x) == 1) c(x, ".") else x) > > tmp <- do.call(rbind, tmp) > > colnames(tmp) <- c("X1", "X2") > > F1 <- cbind(F1[-3], tmp) # remove the original column > > rm(tmp) > > > > F1 > > # ID1 ID2 Y1 X1 X2 > > #1 A1 B1 0 NONE . > > #2 A1 B1 1 cf 12 > > #3 A1 B1 0 NONE . > > #4 A2 B2 1 X2 25 > > #5 A2 B3 1 fd 15 > > > > > > Note that cbind dispatches on F1, an object of class "data.frame". > > Therefore it's the method cbind.data.frame that is called and the result > > is also a df, though tmp is a "matrix". > > > > > > Hope this helps, > > > > Rui Barradas > > > > > > Às 20:07 de 22/09/20, Rui Barradas escreveu: > > > Hello, > > > > > > Something like this? > > > > > > > > > F1$Y1 <- +grepl("_", F1$text) > > > F1 <- F1[c(1, 2, 4, 3)] > > > F1 <- tidyr::separate(F1, text, into = c("X1", "X2"), sep = "_", fill = > > > "right") > > > F1 > > > > > > > > > Hope this helps, > > > > > > Rui Barradas > > > > > > Às 19:55 de 22/09/20, Val escreveu: > > >> HI All, > > >> > > >> I am trying to create new columns based on another column string > > >> content. First I want to identify rows that contain a particular > > >> string. If it contains, I want to split the string and create two > > >> variables. > > >> > > >> Here is my sample of data. > > >> F1<-read.table(text="ID1 ID2 text > > >> A1 B1 NONE > > >> A1 B1 cf_12 > > >> A1 B1 NONE > > >> A2 B2 X2_25 > > >> A2 B3 fd_15 ",header=TRUE,stringsAsFactors=F) > > >> If the variable "text" contains this "_" I want to create an indicator > > >> variable as shown below > > >> > > >> F1$Y1 <- ifelse(grepl("_", F1$text),1,0) > > >> > > >> > > >> Then I want to split that string in to two, before "_" and after "_" > > >> and create two variables as shown below > > >> x1= strsplit(as.character(F1$text),'_',2) > > >> > > >> My problem is how to combine this with the original data frame. The > > >> desired output is shown below, > > >> > > >> > > >> ID1 ID2 Y1 X1 X2 > > >> A1 B1 0 NONE . > > >> A1 B1 1 cf 12 > > >> A1 B1 0 NONE . > > >> A2 B2 1 X2 25 > > >> A2 B3 1 fd 15 > > >> > > >> Any help? > > >> Thank you. > > >> > > >> ______________________________________________ > > >> 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. > > > > ______________________________________________ > > 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. > > > > [[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. > [[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.