[R] Split

[Bert Gunter]

That was still slower and doesn't quite give what was requested:

> cbind(F1,utils::strcapture("([^_]*)_(.*)", F1$text,
proto=data.frame(Before_=character(), After_=character())))
  ID1 ID2  text Before_ After_
1  A1  B1  NONE    <NA>   <NA>
2  A1  B1 cf_12      cf     12
3  A1  B1  NONE    <NA>   <NA>
4  A2  B2 X2_25      X2     25
5  A2  B3 fd_15      fd     15

> system.time({
+ cbind(F2,utils::strcapture("([^_]*)_(.*)", F2$text,
proto=data.frame(Before_=character(), After_=character())))
+ }
+ )
   user  system elapsed
 32.712   0.736  33.587

Cheers,
Bert




On Tue, Sep 22, 2020 at 5:45 PM Bill Dunlap <williamwdunlap using gmail.com>
wrote:

> 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$text,
> proto=data.frame(Before_=character(), After_=character()))
>
> -Bill
>
> On Tue, Sep 22, 2020 at 4:25 PM Bert Gunter <bgunter.4567 using gmail.com>
> wrote:
>
>> To be clear, I think Rui's solution is perfectly fine and probably better
>> than what I offer below. But just for fun, I wanted to do it without the
>> lapply().  Here is one way. I think my comments suffice to explain.
>>
>> > ## which are the  non "_" indices?
>> > wh <- grep("_",F1$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.
>> >
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> 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.
>>
>

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