Extract

Thank   you Bert!
However, the last line of the script.

dat |> names() |> _[4:8] <- paste0("s", 1:5)

is giving me an error as shown below
Error: pipe placeholder can only be used as a named argument

Thank you!

On Sat, Jul 20, 2024 at 7:41?PM Bert Gunter <bgunter.4567 at gmail.com> wrote:

Val:
I wanted to add here a base R solution to your problem that I realize
you can happily ignore. However, in the course of puzzling over how to
do it using the R native pipe syntax ("|>") , I learned some new stuff
that I thought others might find useful, and it seemed sensible to
keep the code with this thread for comparison.

 I want to acknowledge that in the course of my labor, I posted a
query to R-Help to which Iris Simmons posted a very clever answer that
I would never have figured out myself and that is used below at the
end to change a subset of the names of the modified data frame via a
pipe.

Here's the whole solution starting from your (excellent!) example dat:

   dat <- dat$string |>
      strsplit(" ") |>
      sapply(FUN = \(x)c(x, rep(NA, 5 - length(x)))) |>
      t() |> cbind(dat, ..2 = _)

   ## And Iris's trick for changing a subset of attributes, i.e. the
"names", in a pipe
   dat |> names() |> _[4:8] <- paste0("s", 1:5)

## and here's the result:

dat

  Year Sex          string s1   s2   s3   s4   s5
1 2002   F        15 xc Ab 15   xc   Ab <NA> <NA>
2 2003   F              14 14 <NA> <NA> <NA> <NA>
3 2004   M  18 xb 25 35 21 18   xb   25   35   21
4 2005   M           13 25 13   25 <NA> <NA> <NA>
5 2006   M 14 ac 256 AV 35 14   ac  256   AV   35
6 2007   F              11 11 <NA> <NA> <NA> <NA>

As I noted previously, all columns beyond Sex are character

Cheers,
Bert


On Fri, Jul 19, 2024 at 12:26?PM Val <valkremk at gmail.com> wrote:

Thank you Jeff and Bert for your help!
The components of the string  could be nixed (i.e,  numeric, character
or date). Once that is splitted it would be easy for me to format it
accordingly.

On Fri, Jul 19, 2024 at 2:10?PM Bert Gunter <bgunter.4567 at gmail.com> wrote:

I did not look closely at the solutions that you were offered, but
note that you did not specify in your post whether the numbers in your
string were to be character or numeric variables after they are broken
out into their own columns. I believe that they are character in the
solutions, but you should check this. If you want them as numeric,
e.g., for further processing, you will need to convert them. Or
vice-versa.

Bert


On Fri, Jul 19, 2024 at 9:52?AM Val <valkremk at gmail.com> wrote:

Hi All,

I want to extract new variables from a string and add it to the dataframe.
Sample data is csv file.

dat<-read.csv(text="Year, Sex,string
2002,F,15 xc Ab
2003,F,14
2004,M,18 xb 25 35 21
2005,M,13 25
2006,M,14 ac 256 AV 35
2007,F,11",header=TRUE)

The string column has  a maximum of five variables. Some rows have all
and others may not have all the five variables. If missing then  fill
it with NA,
Desired result is shown below,


Year,Sex,string, S1, S2, S3 S4,S5
2002,F,15 xc Ab, 15,xc,Ab, NA, NA
2003,F,14, 14,NA,NA,NA,NA
2004,M,18 xb 25 35 21,18, xb, 25, 35, 21
2005,M,13 25,13, 25,NA,NA,NA
2006,M,14 ac 256 AV 35, 14, ac, 256, AV, 35
2007,F,11, 11,NA,NA,NA,NA

Any help?
Thank you in advance.