[R] Split

[Val]

Thank you all for the help!

LMH, Yes I would like to see the alternative.  I am using this for a
large data set and if the  alternative is more efficient than this
then I would be happy.

On Tue, Sep 22, 2020 at 6:25 PM Bert Gunter <bgunter.4567 using 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 <ruipbarradas using 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 using 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 using 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 using 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.